Articles | Volume 16, issue 5
https://doi.org/10.5194/acp-16-3563-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/acp-16-3563-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
17 Mar 2016
Research article |
| 17 Mar 2016
The contrasting roles of water and dust in controlling daily variations in radiative heating of the summertime Saharan heat low
National Centre for Atmospheric Science (NCAS), Leeds,
UK
School of Earth and Environment, University
of Leeds, Leeds, UK
Douglas J. Parker
School of Earth and Environment, University
of Leeds, Leeds, UK
Martin C. Todd
Department of Geography, University of Sussex, Brighton,
UK
Jamie R. Banks
Space and Atmospheric Physics Group, The Blackett
Laboratory, Imperial College, London, UK
Helen E. Brindley
Space and Atmospheric Physics Group, The Blackett
Laboratory, Imperial College, London, UK
Luis Garcia-Carreras
School of Earth and Environment, University
of Leeds, Leeds, UK
Alexander J. Roberts
School of Earth and Environment, University
of Leeds, Leeds, UK
Claire L. Ryder
Department of Meteorology, University of Reading, Reading,
UK
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We use an aerosol model and observations to explore model representation of aerosol emissions from fires in the Amazon. We find that observed aerosol concentrations are captured by the model over deforestation fires in the western Amazon but underestimated over savanna fires in the Cerrado environment. The model underestimates observed aerosol optical depth (AOD) even when the observed aerosol vertical profile is reproduced. We suggest this may be due to uncertainties in the AOD calculation.
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Atmos. Chem. Phys., 17, 5789–5807, https://doi.org/10.5194/acp-17-5789-2017, https://doi.org/10.5194/acp-17-5789-2017, 2017
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This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
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Joseph Smith, Cathryn Birch, John Marsham, Simon Peatman, Massimo Bollasina, and George Pankiewicz
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Revised manuscript accepted for AMT
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Jianyu Zheng, Zhibo Zhang, Hongbin Yu, Anne Garnier, Qianqian Song, Chenxi Wang, Claudia Di Biagio, Jasper F. Kok, Yevgeny Derimian, and Claire Ryder
Atmos. Chem. Phys., 23, 8271–8304, https://doi.org/10.5194/acp-23-8271-2023, https://doi.org/10.5194/acp-23-8271-2023, 2023
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We developed a multi-year satellite-based retrieval of dust optical depth at 10 µm and the coarse-mode dust effective diameter over global oceans. It reveals climatological coarse-mode dust transport patterns and regional differences over the North Atlantic, the Indian Ocean and the North Pacific.
Claire L. Ryder, Clèment Bézier, Helen F. Dacre, Rory Clarkson, Vassilis Amiridis, Eleni Marinou, Emmanouil Proestakis, Zak Kipling, Angela Benedetti, Mark Parrington, Samuel Rémy, and Mark Vaughan
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Eleni Drakaki, Vassilis Amiridis, Alexandra Tsekeri, Antonis Gkikas, Emmanouil Proestakis, Sotirios Mallios, Stavros Solomos, Christos Spyrou, Eleni Marinou, Claire L. Ryder, Demetri Bouris, and Petros Katsafados
Atmos. Chem. Phys., 22, 12727–12748, https://doi.org/10.5194/acp-22-12727-2022, https://doi.org/10.5194/acp-22-12727-2022, 2022
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State-of-the-art atmospheric dust models have limitations in accounting for a realistic dust size distribution (emission, transport). We modify the parameterization of the mineral dust cycle by including particles with diameter >20 μm, as indicated by observations over deserts. Moreover, we investigate the effects of reduced settling velocities of dust particles. Model results are evaluated using airborne and spaceborne dust measurements above Cabo Verde.
Anthony C. Jones, Adrian Hill, John Hemmings, Pascal Lemaitre, Arnaud Quérel, Claire L. Ryder, and Stephanie Woodward
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Maya Ben-Yami, Hilke Oetjen, Helen Brindley, William Cossich, Dulce Lajas, Tiziano Maestri, Davide Magurno, Piera Raspollini, Luca Sgheri, and Laura Warwick
Atmos. Meas. Tech., 15, 1755–1777, https://doi.org/10.5194/amt-15-1755-2022, https://doi.org/10.5194/amt-15-1755-2022, 2022
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Alcide Zhao, Claire L. Ryder, and Laura J. Wilcox
Atmos. Chem. Phys., 22, 2095–2119, https://doi.org/10.5194/acp-22-2095-2022, https://doi.org/10.5194/acp-22-2095-2022, 2022
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The CMIP6 models' simulated dust processes are getting more uncertain as models become more sophisticated. Of particular challenge are the links between dust cycles and optical properties, and we recommend more detailed output relating to dust cycles in future intercomparison projects to constrain such links. Also, models struggle to capture certain key regional dust processes such as dust accumulation along the slope of the Himalayas and dust seasonal cycles in North China and North America.
Hongbin Yu, Qian Tan, Lillian Zhou, Yaping Zhou, Huisheng Bian, Mian Chin, Claire L. Ryder, Robert C. Levy, Yaswant Pradhan, Yingxi Shi, Qianqian Song, Zhibo Zhang, Peter R. Colarco, Dongchul Kim, Lorraine A. Remer, Tianle Yuan, Olga Mayol-Bracero, and Brent N. Holben
Atmos. Chem. Phys., 21, 12359–12383, https://doi.org/10.5194/acp-21-12359-2021, https://doi.org/10.5194/acp-21-12359-2021, 2021
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This study characterizes a historic African dust intrusion into the Caribbean Basin in June 2020 using satellites and NASA GEOS. Dust emissions in West Africa were large albeit not extreme. However, a unique synoptic system accumulated the dust near the coast for about 4 d before it was ventilated. Although GEOS reproduced satellite-observed plume tracks well, it substantially underestimated dust emissions and did not lift up dust high enough for ensuing long-range transport.
Rei Kudo, Henri Diémoz, Victor Estellés, Monica Campanelli, Masahiro Momoi, Franco Marenco, Claire L. Ryder, Osamu Ijima, Akihiro Uchiyama, Kouichi Nakashima, Akihiro Yamazaki, Ryoji Nagasawa, Nozomu Ohkawara, and Haruma Ishida
Atmos. Meas. Tech., 14, 3395–3426, https://doi.org/10.5194/amt-14-3395-2021, https://doi.org/10.5194/amt-14-3395-2021, 2021
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Jessica C. A. Baker, Luis Garcia-Carreras, Manuel Gloor, John H. Marsham, Wolfgang Buermann, Humberto R. da Rocha, Antonio D. Nobre, Alessandro Carioca de Araujo, and Dominick V. Spracklen
Hydrol. Earth Syst. Sci., 25, 2279–2300, https://doi.org/10.5194/hess-25-2279-2021, https://doi.org/10.5194/hess-25-2279-2021, 2021
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Evapotranspiration (ET) is a vital part of the Amazon water cycle, but it is difficult to measure over large areas. In this study, we compare spatial patterns, seasonality, and recent trends in Amazon ET from a water-budget analysis with estimates from satellites, reanalysis, and global climate models. We find large differences between products, showing that many widely used datasets and climate models may not provide a reliable representation of this crucial variable over the Amazon.
David MacLeod, Mary Kilavi, Emmah Mwangi, Maurine Ambani, Michael Osunga, Joanne Robbins, Richard Graham, Pedram Rowhani, and Martin C. Todd
Nat. Hazards Earth Syst. Sci., 21, 261–277, https://doi.org/10.5194/nhess-21-261-2021, https://doi.org/10.5194/nhess-21-261-2021, 2021
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Forecasts of natural hazards save lives. But the accuracy of forecasts must be evaluated before use. Here we evaluate heavy rainfall advisories over Kenya. We assess their ability to anticipate heavy rainfall and show how well they warned of recent floods which had significant impacts. We find that although they effectively warn of heavy rainfall and flooding, issues such as a lack of spatial detail limit their utility for systematic approaches to preparedness.
Richard J. Bantges, Helen E. Brindley, Jonathan E. Murray, Alan E. Last, Jacqueline E. Russell, Cathryn Fox, Stuart Fox, Chawn Harlow, Sebastian J. O'Shea, Keith N. Bower, Bryan A. Baum, Ping Yang, Hilke Oetjen, and Juliet C. Pickering
Atmos. Chem. Phys., 20, 12889–12903, https://doi.org/10.5194/acp-20-12889-2020, https://doi.org/10.5194/acp-20-12889-2020, 2020
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Understanding how ice clouds influence the Earth's energy balance remains a key challenge for predicting the future climate. These clouds are ubiquitous and are composed of ice crystals that have complex shapes that are incredibly difficult to model. This work exploits new measurements of the Earth's emitted thermal energy made from instruments flown on board an aircraft to test how well the latest ice cloud models can represent these clouds. Results indicate further developments are required.
Debbie O'Sullivan, Franco Marenco, Claire L. Ryder, Yaswant Pradhan, Zak Kipling, Ben Johnson, Angela Benedetti, Melissa Brooks, Matthew McGill, John Yorks, and Patrick Selmer
Atmos. Chem. Phys., 20, 12955–12982, https://doi.org/10.5194/acp-20-12955-2020, https://doi.org/10.5194/acp-20-12955-2020, 2020
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Mineral dust is an important component of the climate system, and we assess how well it is predicted by two operational models. We flew an aircraft in the dust layers in the eastern Atlantic, and we also make use of satellites. We show that models predict the dust layer too low and that it predicts the particles to be too small. We believe that these discrepancies may be overcome if models can be constrained with operational observations of dust vertical and size-resolved distribution.
Teruyuki Nakajima, Monica Campanelli, Huizheng Che, Victor Estellés, Hitoshi Irie, Sang-Woo Kim, Jhoon Kim, Dong Liu, Tomoaki Nishizawa, Govindan Pandithurai, Vijay Kumar Soni, Boossarasiri Thana, Nas-Urt Tugjsurn, Kazuma Aoki, Sujung Go, Makiko Hashimoto, Akiko Higurashi, Stelios Kazadzis, Pradeep Khatri, Natalia Kouremeti, Rei Kudo, Franco Marenco, Masahiro Momoi, Shantikumar S. Ningombam, Claire L. Ryder, Akihiro Uchiyama, and Akihiro Yamazaki
Atmos. Meas. Tech., 13, 4195–4218, https://doi.org/10.5194/amt-13-4195-2020, https://doi.org/10.5194/amt-13-4195-2020, 2020
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This paper overviews the progress in sky radiometer technology and the development of the network called SKYNET. It is found that the technology has produced useful on-site calibration methods, retrieval algorithms, and data analyses from sky radiometer observations of aerosol, cloud, water vapor, and ozone. The paper also discusses current issues of SKYNET to provide better information for the community.
Claire L. Ryder, Eleanor J. Highwood, Adrian Walser, Petra Seibert, Anne Philipp, and Bernadett Weinzierl
Atmos. Chem. Phys., 19, 15353–15376, https://doi.org/10.5194/acp-19-15353-2019, https://doi.org/10.5194/acp-19-15353-2019, 2019
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Mineral dust is lifted into the atmosphere from desert regions, where it can be transported over thousands of kilometres around the world. Dust impacts weather, climate, aviation, and air quality. We evaluate new aircraft observations of dust size. We find that the largest particles typically omitted by models have a significant impact on the interactions of dust with radiation and therefore climate. We also find that large dust particles are retained in the atmosphere longer than expected.
Carly L. Reddington, William T. Morgan, Eoghan Darbyshire, Joel Brito, Hugh Coe, Paulo Artaxo, Catherine E. Scott, John Marsham, and Dominick V. Spracklen
Atmos. Chem. Phys., 19, 9125–9152, https://doi.org/10.5194/acp-19-9125-2019, https://doi.org/10.5194/acp-19-9125-2019, 2019
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We use an aerosol model and observations to explore model representation of aerosol emissions from fires in the Amazon. We find that observed aerosol concentrations are captured by the model over deforestation fires in the western Amazon but underestimated over savanna fires in the Cerrado environment. The model underestimates observed aerosol optical depth (AOD) even when the observed aerosol vertical profile is reproduced. We suggest this may be due to uncertainties in the AOD calculation.
Christophe Bellisario, Helen E. Brindley, Simon F. B. Tett, Rolando Rizzi, Gianluca Di Natale, Luca Palchetti, and Giovanni Bianchini
Atmos. Chem. Phys., 19, 7927–7937, https://doi.org/10.5194/acp-19-7927-2019, https://doi.org/10.5194/acp-19-7927-2019, 2019
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We explore the possibility of inferring far-infrared downwelling radiances from mid-infrared observations to better constrain radiation schemes in climate models. Our results imply that while it is feasible to use this type of approach, the quality of the extension will be strongly dependent on the noise characteristics of the observations and on the accurate characterisation of the atmospheric state.
Jamie R. Banks, Anja Hünerbein, Bernd Heinold, Helen E. Brindley, Hartwig Deneke, and Kerstin Schepanski
Atmos. Chem. Phys., 19, 6893–6911, https://doi.org/10.5194/acp-19-6893-2019, https://doi.org/10.5194/acp-19-6893-2019, 2019
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Saharan dust storms may be observed over the desert using false-colour infrared satellite imagery; in one widely used scheme dust displays characteristic pink colours. Simulating satellite imagery using a dust transport model, we confirm that water vapour is a major control on the apparent colour of dust in the false-colour imagery and that dust displays its deepest colours when it is at a high altitude and when the atmosphere is dry. Water vapour can obscure the presence of low-altitude dust.
Seshagiri Rao Kolusu, Mohammad Shamsudduha, Martin C. Todd, Richard G. Taylor, David Seddon, Japhet J. Kashaigili, Girma Y. Ebrahim, Mark O. Cuthbert, James P. R. Sorensen, Karen G. Villholth, Alan M. MacDonald, and Dave A. MacLeod
Hydrol. Earth Syst. Sci., 23, 1751–1762, https://doi.org/10.5194/hess-23-1751-2019, https://doi.org/10.5194/hess-23-1751-2019, 2019
Franco Marenco, Claire Ryder, Victor Estellés, Debbie O'Sullivan, Jennifer Brooke, Luke Orgill, Gary Lloyd, and Martin Gallagher
Atmos. Chem. Phys., 18, 17655–17668, https://doi.org/10.5194/acp-18-17655-2018, https://doi.org/10.5194/acp-18-17655-2018, 2018
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The AER-D airborne campaign characterised Saharan dust in the eastern Atlantic. We report an instance of unusual vertical structure of the Saharan Air Layer during an intense event, showing a large radiative impact and correlated with anomalous lightning activity. Moreover, we report a significant presence of giant dust particles. This is important because most models would miss the giant particles. Our findings may change the way we represent dust transport and deposition in the Atlantic.
Claire L. Ryder, Franco Marenco, Jennifer K. Brooke, Victor Estelles, Richard Cotton, Paola Formenti, James B. McQuaid, Hannah C. Price, Dantong Liu, Patrick Ausset, Phil D. Rosenberg, Jonathan W. Taylor, Tom Choularton, Keith Bower, Hugh Coe, Martin Gallagher, Jonathan Crosier, Gary Lloyd, Eleanor J. Highwood, and Benjamin J. Murray
Atmos. Chem. Phys., 18, 17225–17257, https://doi.org/10.5194/acp-18-17225-2018, https://doi.org/10.5194/acp-18-17225-2018, 2018
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Every year, millions of tons of Saharan dust particles are carried across the Atlantic by the wind, where they can affect weather patterns and climate. Their sizes span orders of magnitude, but the largest (over 10 microns – around the width of a human hair) are difficult to measure and few observations exist. Here we show new aircraft observations of large dust particles, finding more than we would expect, and we quantify their properties which allow them to interact with atmospheric radiation.
Qianqian Song, Zhibo Zhang, Hongbin Yu, Seiji Kato, Ping Yang, Peter Colarco, Lorraine A. Remer, and Claire L. Ryder
Atmos. Chem. Phys., 18, 11303–11322, https://doi.org/10.5194/acp-18-11303-2018, https://doi.org/10.5194/acp-18-11303-2018, 2018
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Mineral dust is the most abundant atmospheric aerosol component in terms of dry mass. In this study, we integrate recent aircraft measurements of dust microphysical and optical properties with satellite retrievals of aerosol and radiative fluxes to quantify the dust direct radiative effects on the shortwave and longwave radiation at both the top of the atmosphere and the surface in the tropical North Atlantic during summer months.
Angela Benedetti, Jeffrey S. Reid, Peter Knippertz, John H. Marsham, Francesca Di Giuseppe, Samuel Rémy, Sara Basart, Olivier Boucher, Ian M. Brooks, Laurent Menut, Lucia Mona, Paolo Laj, Gelsomina Pappalardo, Alfred Wiedensohler, Alexander Baklanov, Malcolm Brooks, Peter R. Colarco, Emilio Cuevas, Arlindo da Silva, Jeronimo Escribano, Johannes Flemming, Nicolas Huneeus, Oriol Jorba, Stelios Kazadzis, Stefan Kinne, Thomas Popp, Patricia K. Quinn, Thomas T. Sekiyama, Taichu Tanaka, and Enric Terradellas
Atmos. Chem. Phys., 18, 10615–10643, https://doi.org/10.5194/acp-18-10615-2018, https://doi.org/10.5194/acp-18-10615-2018, 2018
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Numerical prediction of aerosol particle properties has become an important activity at many research and operational weather centers. This development is due to growing interest from a diverse set of stakeholders, such as air quality regulatory bodies, aviation authorities, solar energy plant managers, climate service providers, and health professionals. This paper describes the advances in the field and sets out requirements for observations for the sustainability of these activities.
Jamie R. Banks, Kerstin Schepanski, Bernd Heinold, Anja Hünerbein, and Helen E. Brindley
Atmos. Chem. Phys., 18, 9681–9703, https://doi.org/10.5194/acp-18-9681-2018, https://doi.org/10.5194/acp-18-9681-2018, 2018
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Satellite observations are used to visualize dust storms over the Sahara, and specific infrared channel combinations can highlight dust with distinctive pink colours. Using output from a dust-atmosphere model to simulate satellite imagery, we explore the consequences of particle size, shape, and refractive index for the colour of dust in the imagery. Particles with a radius of ~ 1.5 microns perturb the colour the most and an assumption of spherical dust appears to be insufficient.
Alexander J. Roberts, Margaret J. Woodage, John H. Marsham, Ellie J. Highwood, Claire L. Ryder, Willie McGinty, Simon Wilson, and Julia Crook
Atmos. Chem. Phys., 18, 9025–9048, https://doi.org/10.5194/acp-18-9025-2018, https://doi.org/10.5194/acp-18-9025-2018, 2018
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The summer Saharan dust hotspot is seasonally tied to the occurrence of convective storms. Global weather and climate models parameterise convection and so are unable to represent their associated dust uplift (haboobs). However, this work shows that even when simulations represent convection explicitly: (1) dust fields are not strongly affected, (2) convective storms are too small, (3) haboobs are too weak and (4) the land surface (bare soil and soil moisture) is dominant in controlling dust.
Gillian D. Thornhill, Claire L. Ryder, Eleanor J. Highwood, Len C. Shaffrey, and Ben T. Johnson
Atmos. Chem. Phys., 18, 5321–5342, https://doi.org/10.5194/acp-18-5321-2018, https://doi.org/10.5194/acp-18-5321-2018, 2018
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We investigated the impact on the regional climate of different amounts of smoke emission (aerosol) from the burning of vegetation in South America using a climate model. We looked at differences between high and low smoke emissions and found impacts from the higher smoke emissions on the amount of cloud cover, solar radiation reaching the surface, wind patterns and rainfall. This means the local climate may be affected if there is more deforestation and more smoke from burning of vegetation.
Jake J. Gristey, J. Christine Chiu, Robert J. Gurney, Cyril J. Morcrette, Peter G. Hill, Jacqueline E. Russell, and Helen E. Brindley
Atmos. Chem. Phys., 18, 5129–5145, https://doi.org/10.5194/acp-18-5129-2018, https://doi.org/10.5194/acp-18-5129-2018, 2018
Dantong Liu, Jonathan W. Taylor, Jonathan Crosier, Nicholas Marsden, Keith N. Bower, Gary Lloyd, Claire L. Ryder, Jennifer K. Brooke, Richard Cotton, Franco Marenco, Alan Blyth, Zhiqiang Cui, Victor Estelles, Martin Gallagher, Hugh Coe, and Tom W. Choularton
Atmos. Chem. Phys., 18, 3817–3838, https://doi.org/10.5194/acp-18-3817-2018, https://doi.org/10.5194/acp-18-3817-2018, 2018
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This article presents measurements of aerosol properties off the coast of west Africa during August 2015. For the first time, an airborne laser-induced incandescence instrument was deployed to measure the hematite content of dust. The single scattering albedo of dust was found to be influenced by the hematite content, but depended on the dust source and potential dust age. This highlights the importance of size-dependent composition in determining the optical properties of dust.
Netsanet K. Alamirew, Martin C. Todd, Claire L. Ryder, John H. Marsham, and Yi Wang
Atmos. Chem. Phys., 18, 1241–1262, https://doi.org/10.5194/acp-18-1241-2018, https://doi.org/10.5194/acp-18-1241-2018, 2018
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This paper quantifies the radiative effects of dust and water vapour in the Saharan heat low. Dust has a warming effect at the top of the atmosphere while cooling the surface. Water vapour has a warming effect both at the top of atmosphere and the surface. We find dust and water vapour have similar effects in driving the variability in the top-of-atmosphere radiative budget, while dust has a stronger effect than water vapour in controlling day-to-day variability of the surface radiative budget.
Adriana Rocha-Lima, J. Vanderlei Martins, Lorraine A. Remer, Martin Todd, John H. Marsham, Sebastian Engelstaedter, Claire L. Ryder, Carolina Cavazos-Guerra, Paulo Artaxo, Peter Colarco, and Richard Washington
Atmos. Chem. Phys., 18, 1023–1043, https://doi.org/10.5194/acp-18-1023-2018, https://doi.org/10.5194/acp-18-1023-2018, 2018
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We present results of ground-based measurements and subsequent laboratory analysis of Sahara dust samples collected in Algeria and Mauritania during the Fennec campaign in 2011. The results show that the sampled dust has low absorption characteristics and exhibits a distinct spectral bow-like shape. We find distinctive differences in the composition and optical characteristics of the dust from the two sites, corroborating with other studies that not all Saharan dust is the same.
Anna Mackie, Paul I. Palmer, and Helen Brindley
Atmos. Chem. Phys., 17, 15095–15119, https://doi.org/10.5194/acp-17-15095-2017, https://doi.org/10.5194/acp-17-15095-2017, 2017
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We compare the balance of solar and thermal radiation at the surface and the top of the atmosphere from a forecasting model to observations at a site in Niamey, Niger, in the Sahel. To interpret the energy budgets we examine other factors, such as cloud properties, water vapour and aerosols, which we use to understand the differences between the observation and model. We find that some differences are linked to lack of ice in clouds, underestimated aerosol loading and surface temperatures.
Peter Knippertz, Andreas H. Fink, Adrien Deroubaix, Eleanor Morris, Flore Tocquer, Mat J. Evans, Cyrille Flamant, Marco Gaetani, Christophe Lavaysse, Celine Mari, John H. Marsham, Rémi Meynadier, Abalo Affo-Dogo, Titike Bahaga, Fabien Brosse, Konrad Deetz, Ridha Guebsi, Issaou Latifou, Marlon Maranan, Philip D. Rosenberg, and Andreas Schlueter
Atmos. Chem. Phys., 17, 10893–10918, https://doi.org/10.5194/acp-17-10893-2017, https://doi.org/10.5194/acp-17-10893-2017, 2017
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In June–July 2016 DACCIWA (Dynamics–Aerosol–Chemistry–Cloud Interactions in West Africa), a large, EU-funded European–African project, organised an international field campaign in densely populated southern West Africa, including measurements from ground sites, research aircraft, weather balloons and urban sites. This paper gives an overview of the atmospheric evolution during this period focusing on meteorological (precipitation, cloudiness, winds) and composition (gases, particles) aspects.
John C. Kealy, Franco Marenco, John H. Marsham, Luis Garcia-Carreras, Pete N. Francis, Michael C. Cooke, and James Hocking
Atmos. Chem. Phys., 17, 5789–5807, https://doi.org/10.5194/acp-17-5789-2017, https://doi.org/10.5194/acp-17-5789-2017, 2017
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Using novel methods of cloud detection from aircraft data over the Sahara desert, we evaluate the performance of the Meteosat satellite in measuring cloud properties: namely, the cloud mask and the cloud-top height. We find that the cloud mask can justifiably be used for many applications (such as creating a detailed Saharan cloud climatology), and we also discuss its limitations. As for the cloud-top height, we show that the dataset cannot yet be considered robust in this part of the world.
Jamie R. Banks, Helen E. Brindley, Georgiy Stenchikov, and Kerstin Schepanski
Atmos. Chem. Phys., 17, 3987–4003, https://doi.org/10.5194/acp-17-3987-2017, https://doi.org/10.5194/acp-17-3987-2017, 2017
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From an 11-year analysis of satellite measurements of atmospheric dust presence over the Red Sea, it is clear that there is a strong north–south gradient in dust activity and a pronounced interannual variability in this activity. Analysing two commonly used satellite retrieval methods to quantify dust presence, we find that under the most extreme dust storm conditions the measured dust optical thicknesses can diverge strongly between the two methods.
Céline Planche, Graham W. Mann, Kenneth S. Carslaw, Mohit Dalvi, John H. Marsham, and Paul R. Field
Atmos. Chem. Phys., 17, 3371–3384, https://doi.org/10.5194/acp-17-3371-2017, https://doi.org/10.5194/acp-17-3371-2017, 2017
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A convection-permitting limited area model with prognostic aerosol microphysics is applied to investigate how concentrations of cloud condensation nuclei (CCN) in the marine boundary layer are affected by high-resolution dynamical and thermodynamic fields at sub-climate model scale. We gain new insight into the way primary sea-salt and secondary sulfate particles contribute to the overall CCN variance, and find a marked difference in the variability of super- and sub-micron CCN.
Anna R. Esteve, Eleanor J. Highwood, and Claire L. Ryder
Atmos. Chem. Phys., 16, 7639–7651, https://doi.org/10.5194/acp-16-7639-2016, https://doi.org/10.5194/acp-16-7639-2016, 2016
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The radiative effect of aerosols over Europe during the EUCAARI-LONGREX campaign has been calculated using measurements made by the FAAM BAe-146 aircraft and radiative transfer modelling. For one specially designed flight, simulated irradiances have been compared to radiation measurements to explore the validity of model assumptions. We have quantified the uncertainties in our calculations due to the way in which aerosols and other parameters are represented in a radiative transfer model.
Bernd Heinold, Ina Tegen, Kerstin Schepanski, and Jamie R. Banks
Geosci. Model Dev., 9, 765–777, https://doi.org/10.5194/gmd-9-765-2016, https://doi.org/10.5194/gmd-9-765-2016, 2016
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In the aerosol-climate model ECHAM6-HAM2, dust source activation (DSA) observations from MSG satellite are used to replace the current Saharan source map. The new setup provides more realistically distributed, up to 20 % higher annual Saharan emissions. Modeled dust AOT is partly improved in the Sahara-Sahel region, as is the spatial variability. As a comparison to sub-daily MSG DSAs and a regional model shows, the representation of meteorological drivers of dust uplift remains a critical issue.
S. R. Kolusu, J. H. Marsham, J. Mulcahy, B. Johnson, C. Dunning, M. Bush, and D. V. Spracklen
Atmos. Chem. Phys., 15, 12251–12266, https://doi.org/10.5194/acp-15-12251-2015, https://doi.org/10.5194/acp-15-12251-2015, 2015
S. Osipov, G. Stenchikov, H. Brindley, and J. Banks
Atmos. Chem. Phys., 15, 9537–9553, https://doi.org/10.5194/acp-15-9537-2015, https://doi.org/10.5194/acp-15-9537-2015, 2015
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The radiative effect of dust over the Arabian Peninsula for different surfaces and for a range of optical depths is calculated and tested using satellite and ground-based observations.
C. L. Ryder, J. B. McQuaid, C. Flamant, P. D. Rosenberg, R. Washington, H. E. Brindley, E. J. Highwood, J. H. Marsham, D. J. Parker, M. C. Todd, J. R. Banks, J. K. Brooke, S. Engelstaedter, V. Estelles, P. Formenti, L. Garcia-Carreras, C. Kocha, F. Marenco, H. Sodemann, C. J. T. Allen, A. Bourdon, M. Bart, C. Cavazos-Guerra, S. Chevaillier, J. Crosier, E. Darbyshire, A. R. Dean, J. R. Dorsey, J. Kent, D. O'Sullivan, K. Schepanski, K. Szpek, J. Trembath, and A. Woolley
Atmos. Chem. Phys., 15, 8479–8520, https://doi.org/10.5194/acp-15-8479-2015, https://doi.org/10.5194/acp-15-8479-2015, 2015
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Measurements of the Saharan atmosphere and of atmospheric mineral dust are lacking but are vital to our understanding of the climate of this region and their impacts further afield. Novel observations were made by the Fennec climate programme during June 2011 and 2012 using ground-based, remote sensing and airborne platforms. Here we describe the airborne observations and the contributions they have made to furthering our understanding of the Saharan climate system.
C. A. Randles, S. Kinne, G. Myhre, M. Schulz, P. Stier, J. Fischer, L. Doppler, E. Highwood, C. Ryder, B. Harris, J. Huttunen, Y. Ma, R. T. Pinker, B. Mayer, D. Neubauer, R. Hitzenberger, L. Oreopoulos, D. Lee, G. Pitari, G. Di Genova, J. Quaas, F. G. Rose, S. Kato, S. T. Rumbold, I. Vardavas, N. Hatzianastassiou, C. Matsoukas, H. Yu, F. Zhang, H. Zhang, and P. Lu
Atmos. Chem. Phys., 13, 2347–2379, https://doi.org/10.5194/acp-13-2347-2013, https://doi.org/10.5194/acp-13-2347-2013, 2013
C. L. Ryder, E. J. Highwood, P. D. Rosenberg, J. Trembath, J. K. Brooke, M. Bart, A. Dean, J. Crosier, J. Dorsey, H. Brindley, J. Banks, J. H. Marsham, J. B. McQuaid, H. Sodemann, and R. Washington
Atmos. Chem. Phys., 13, 303–325, https://doi.org/10.5194/acp-13-303-2013, https://doi.org/10.5194/acp-13-303-2013, 2013
Related subject area
Subject: Radiation | Research Activity: Field Measurements | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)
Tethered balloon-borne observations of thermal-infrared irradiance and cooling rate profiles in the Arctic atmospheric boundary layer
Assessing the cloud radiative bias at Macquarie Island in the ACCESS-AM2 model
Surface energy balance fluxes in a suburban area of Beijing: energy partitioning variability
Effects of variable ice–ocean surface properties and air mass transformation on the Arctic radiative energy budget
Broadband and filter radiometers at Ross Island, Antarctica: Detection of cloud ice phase versus liquid water influences on shortwave and longwave radiation
Airborne observations of the surface cloud radiative effect during different seasons over sea ice and open ocean in the Fram Strait
Assessment of spectral UV radiation at Marambio Base, Antarctic Peninsula
Parameterization of downward long-wave radiation based on long-term baseline surface radiation measurements in China
An assessment of land energy balance over East Asia from multiple lines of evidence and the roles of the Tibet Plateau, aerosols, and clouds
Ozone, DNA-active UV radiation, and cloud changes for the near-global mean and at high latitudes due to enhanced greenhouse gas concentrations
In situ observation of warm atmospheric layer and the heat contribution of suspended dust over the Tarim Basin
Eight-year variations in atmospheric radiocesium in Fukushima city
Variability and trends in surface solar spectral ultraviolet irradiance in Italy: on the influence of geopotential height and lower-stratospheric ozone
Fifty-six years of surface solar radiation and sunshine duration over São Paulo, Brazil: 1961–2016
Changes in the surface broadband shortwave radiation budget during the 2017 eclipse
Reassessment of shortwave surface cloud radiative forcing in the Arctic: consideration of surface-albedo–cloud interactions
Deposition of brown carbon onto snow: changes in snow optical and radiative properties
Solar UV radiation measurements in Marambio, Antarctica, during years 2017–2019
A revisiting of the parametrization of downward longwave radiation in summer over the Tibetan Plateau based on high-temporal-resolution measurements
Trends in surface radiation and cloud radiative effect at four Swiss sites for the 1996–2015 period
Can downwelling far-infrared radiances over Antarctica be estimated from mid-infrared information?
Measurements of spectral irradiance during the solar eclipse of 21 August 2017: reassessment of the effect of solar limb darkening and of changes in total ozone
UV measurements at Marambio and Ushuaia during 2000–2010
On the suitability of current atmospheric reanalyses for regional warming studies over China
A long-term time series of global and diffuse photosynthetically active radiation in the Mediterranean: interannual variability and cloud effects
Long-term series and trends in surface solar radiation in Athens, Greece
Reconstruction and analysis of erythemal UV radiation time series from Hradec Králové (Czech Republic) over the past 50 years
Trends in erythemal doses at the Polish Polar Station, Hornsund, Svalbard based on the homogenized measurements (1996–2016) and reconstructed data (1983–1995)
Effects of vernal equinox solar eclipse on temperature and wind direction in Switzerland
Sky radiance at a coastline and effects of land and ocean reflectivities
Impact of aerosols and clouds on decadal trends in all-sky solar radiation over the Netherlands (1966–2015)
Contributions of surface solar radiation and precipitation to the spatiotemporal patterns of surface and air warming in China from 1960 to 2003
Multiresolution analysis of the spatiotemporal variability in global radiation observed by a dense network of 99 pyranometers
Validation of satellite-based noontime UVI with NDACC ground-based instruments: influence of topography, environment and satellite overpass time
Is global dimming and brightening in Japan limited to urban areas?
The climatology of planetary boundary layer height in China derived from radiosonde and reanalysis data
Detection of dimming/brightening in Italy from homogenized all-sky and clear-sky surface solar radiation records and underlying causes (1959–2013)
Comparison of land–atmosphere interaction at different surface types in the mid- to lower reaches of the Yangtze River valley
Spectral optical layer properties of cirrus from collocated airborne measurements and simulations
Local short-term variability in solar irradiance
Global dimming and urbanization: did stronger negative SSR trends collocate with regions of population growth?
Short- and long-term variability of spectral solar UV irradiance at Thessaloniki, Greece: effects of changes in aerosols, total ozone and clouds
On the progress of the 2015–2016 El Niño event
Role of radiatively forced temperature changes in enhanced semi-arid warming in the cold season over east Asia
Assessment of long-term WRF–CMAQ simulations for understanding direct aerosol effects on radiation "brightening" in the United States
Comparison of OMI UV observations with ground-based measurements at high northern latitudes
Characterisation of J(O1D) at Cape Grim 2000–2005
On the scaling of the solar incident flux
Analysis of actinic flux profiles measured from an ozonesonde balloon
Relations between erythemal UV dose, global solar radiation, total ozone column and aerosol optical depth at Uccle, Belgium
Michael Lonardi, Elisa F. Akansu, André Ehrlich, Mauro Mazzola, Christian Pilz, Matthew D. Shupe, Holger Siebert, and Manfred Wendisch
Atmos. Chem. Phys., 24, 1961–1978, https://doi.org/10.5194/acp-24-1961-2024, https://doi.org/10.5194/acp-24-1961-2024, 2024
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Profiles of thermal-infrared irradiance were measured at two Arctic sites. The presence or lack of clouds influences the vertical structure of these observations. In particular, the cloud top region is a source of radiative energy that can promote cooling and mixing in the cloud layer. Simulations are used to further characterize how the amount of water in the cloud modifies this forcing. A case study additionally showcases the evolution of the radiation profiles in a dynamic atmosphere.
Zhangcheng Pei, Sonya L. Fiddes, W. John R. French, Simon P. Alexander, Marc D. Mallet, Peter Kuma, and Adrian McDonald
Atmos. Chem. Phys., 23, 14691–14714, https://doi.org/10.5194/acp-23-14691-2023, https://doi.org/10.5194/acp-23-14691-2023, 2023
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In this paper, we use ground-based observations to evaluate a climate model and a satellite product in simulating surface radiation and investigate how radiation biases are influenced by cloud properties over the Southern Ocean. We find that significant radiation biases exist in both the model and satellite. The cloud fraction and cloud occurrence play an important role in affecting radiation biases. We suggest further development for the model and satellite using ground-based observations.
Junxia Dou, Sue Grimmond, Shiguang Miao, Bei Huang, Huimin Lei, and Mingshui Liao
Atmos. Chem. Phys., 23, 13143–13166, https://doi.org/10.5194/acp-23-13143-2023, https://doi.org/10.5194/acp-23-13143-2023, 2023
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Multi-timescale variations in surface energy fluxes in a suburb of Beijing are analyzed using 16-month observations. Compared to previous suburban areas, this study site has larger seasonal variability in energy partitioning, and summer and winter Bowen ratios are at the lower and higher end of those at other suburban sites, respectively. Our analysis indicates that precipitation, irrigation, crop/vegetation growth activity, and land use/cover all play critical roles in energy partitioning.
Manfred Wendisch, Johannes Stapf, Sebastian Becker, André Ehrlich, Evelyn Jäkel, Marcus Klingebiel, Christof Lüpkes, Michael Schäfer, and Matthew D. Shupe
Atmos. Chem. Phys., 23, 9647–9667, https://doi.org/10.5194/acp-23-9647-2023, https://doi.org/10.5194/acp-23-9647-2023, 2023
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Atmospheric radiation measurements have been conducted during two field campaigns using research aircraft. The data are analyzed to see if the near-surface air in the Arctic is warmed or cooled if warm–humid air masses from the south enter the Arctic or cold–dry air moves from the north from the Arctic to mid-latitude areas. It is important to study these processes and to check if climate models represent them well. Otherwise it is not possible to reliably forecast the future Arctic climate.
Kristopher Scarci, Ryan Scott, Madison Ghiz, Andrew Vogelmann, and Dan Lubin
EGUsphere, https://doi.org/10.5194/egusphere-2023-1665, https://doi.org/10.5194/egusphere-2023-1665, 2023
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We demonstrate what can be learned about an Antarctic region's climate from basic atmospheric irradiance measurements made by broadband and filter radiometers, instruments suitable for deployment at very remote sites, assisted by meteorological reanalysis and satellite remote sensing. Analysis of shortwave and longwave irradiance reveals subtle contrasts between meteorological regimes favoring cloud ice versus liquid water, relevant to onset versus inhibition of surface melt over ice shelves.
Sebastian Becker, André Ehrlich, Michael Schäfer, and Manfred Wendisch
Atmos. Chem. Phys., 23, 7015–7031, https://doi.org/10.5194/acp-23-7015-2023, https://doi.org/10.5194/acp-23-7015-2023, 2023
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This study analyses the variability of the warming or cooling effect of clouds on the Arctic surface. Therefore, aircraft radiation measurements were performed over sea ice and open ocean during three seasonally different campaigns. It is found that clouds cool the open-ocean surface most strongly in summer. Over sea ice, clouds warm the surface in spring but have a neutral effect in summer. Due to the variable sea ice extent, clouds warm the surface during spring but cool it during late summer.
Klára Čížková, Kamil Láska, Ladislav Metelka, and Martin Staněk
Atmos. Chem. Phys., 23, 4617–4636, https://doi.org/10.5194/acp-23-4617-2023, https://doi.org/10.5194/acp-23-4617-2023, 2023
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The study deals with ultraviolet (UV) radiation in southern polar conditions, where ozone depletion occurs each spring. A 10-year-long time series of UV spectra from Marambio Base, Antarctic Peninsula, has been studied, with a focus on the changes of UV radiation at different wavelengths and the effects of atmospheric and terrestrial variables like ozone, solar elevation, or cloudiness. At the very short wavelengths, the effect of ozone and its deficiency was clearly observed.
Junli Yang, Jianglin Hu, Qiying Chen, and Weijun Quan
Atmos. Chem. Phys., 23, 4419–4430, https://doi.org/10.5194/acp-23-4419-2023, https://doi.org/10.5194/acp-23-4419-2023, 2023
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Downward long-wave radiation (DLR) affects energy exchange between the land surface and the atmosphere, while it is seldom observed at conventional radiation stations. Therefore, parameterization of DLR based on the near-surface meteorological variables provides a chance to estimate the DLR over most meteorological stations. This work established three parameterizations suited to estimating the DLR over China by using the measurements from the CBSRN with an accuracy of ~6.1 %.
Qiuyan Wang, Hua Zhang, Su Yang, Qi Chen, Xixun Zhou, Bing Xie, Yuying Wang, Guangyu Shi, and Martin Wild
Atmos. Chem. Phys., 22, 15867–15886, https://doi.org/10.5194/acp-22-15867-2022, https://doi.org/10.5194/acp-22-15867-2022, 2022
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The present-day land energy balance over East Asia is estimated for the first time. Results indicate that high aerosol loadings, clouds, and the Tibet Plateau (TP) over East Asia play vital roles in the shortwave budgets, while the TP is responsible for the longwave budgets during this regional energy budget assessment. This study provides a perspective to understand fully how the potential factors influence the diversifying regional energy budget assessments.
Kostas Eleftheratos, John Kapsomenakis, Ilias Fountoulakis, Christos S. Zerefos, Patrick Jöckel, Martin Dameris, Alkiviadis F. Bais, Germar Bernhard, Dimitra Kouklaki, Kleareti Tourpali, Scott Stierle, J. Ben Liley, Colette Brogniez, Frédérique Auriol, Henri Diémoz, Stana Simic, Irina Petropavlovskikh, Kaisa Lakkala, and Kostas Douvis
Atmos. Chem. Phys., 22, 12827–12855, https://doi.org/10.5194/acp-22-12827-2022, https://doi.org/10.5194/acp-22-12827-2022, 2022
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We present the future evolution of DNA-active ultraviolet (UV) radiation in view of increasing greenhouse gases (GHGs) and decreasing ozone depleting substances (ODSs). It is shown that DNA-active UV radiation might increase after 2050 between 50° N–50° S due to GHG-induced reductions in clouds and ozone, something that is likely not to happen at high latitudes, where DNA-active UV radiation will continue its downward trend mainly due to stratospheric ozone recovery from the reduction in ODSs.
Chenglong Zhou, Yuzhi Liu, Qingzhe Zhu, Qing He, Tianliang Zhao, Fan Yang, Wen Huo, Xinghua Yang, and Ali Mamtimin
Atmos. Chem. Phys., 22, 5195–5207, https://doi.org/10.5194/acp-22-5195-2022, https://doi.org/10.5194/acp-22-5195-2022, 2022
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Based on the radiosonde observations, an anomalously warm layer is measured at altitudes between 500 and 300 hPa over the Tarim Basin (TB) with an average intensity of 2.53 and 1.39 K in the spring and summer, respectively. The heat contributions of dust to this anomalously warm atmospheric layer in spring and summer were 13.77 and 10.25 %, respectively. Topographically, the TB is adjacent to the Tibetan Plateau; we propose the concept of the Tibetan heat source’s northward extension.
Akira Watanabe, Mizuo Kajino, Kazuhiko Ninomiya, Yoshitaka Nagahashi, and Atsushi Shinohara
Atmos. Chem. Phys., 22, 675–692, https://doi.org/10.5194/acp-22-675-2022, https://doi.org/10.5194/acp-22-675-2022, 2022
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This study summarizes continuous measurements of surface air concentrations and deposition of radiocesium in Fukushima city over 8 years after the Fukushima nuclear accident. The concentration in the city was high in winter and low in summer (inverse of the forest area). The decreasing trends were much faster in the earlier stage, probably because dissolved cesium discharged faster from the local environment. Biotite might play a key role in circulation of particulate cesium in Fukushima city.
Ilias Fountoulakis, Henri Diémoz, Anna Maria Siani, Alcide di Sarra, Daniela Meloni, and Damiano M. Sferlazzo
Atmos. Chem. Phys., 21, 18689–18705, https://doi.org/10.5194/acp-21-18689-2021, https://doi.org/10.5194/acp-21-18689-2021, 2021
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The variability and trends of solar spectral UV irradiance have been studied for the periods 1996–2020 (for Rome) and 2006–2020 (for Lampedusa, Rome, and Aosta) with respect to the variability and trends of total ozone and geopotential height. Analyses revealed increasing UV in particular months at all sites, possibly due to decreasing lower-stratospheric ozone (at Rome in 1996–2020) and decreasing attenuation by aerosols and/or clouds (at all stations in 2006–2020).
Marcia Akemi Yamasoe, Nilton Manuel Évora Rosário, Samantha Novaes Santos Martins Almeida, and Martin Wild
Atmos. Chem. Phys., 21, 6593–6603, https://doi.org/10.5194/acp-21-6593-2021, https://doi.org/10.5194/acp-21-6593-2021, 2021
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Spatio-temporal disparity to assess global dimming and brightening phenomena has been a critical topic. For instance, few studies addressed surface solar irradiation (SSR) long-term trend in South America. In this study, SSR, sunshine duration (SD) and the diurnal temperature range (DTR) are analysed for São Paulo, Brazil. We found a dimming phase, identified by SSR, SD and DTR, extending till 1983. Then, while SSR is still declining, consistent with cloud increasing, SD and DTR are increasing.
Guoyong Wen, Alexander Marshak, Si-Chee Tsay, Jay Herman, Ukkyo Jeong, Nader Abuhassan, Robert Swap, and Dong Wu
Atmos. Chem. Phys., 20, 10477–10491, https://doi.org/10.5194/acp-20-10477-2020, https://doi.org/10.5194/acp-20-10477-2020, 2020
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We combine the ground-based observations and radiative transfer model to quantify the impact of the 2017 solar eclipse on surface shortwave irradiation reduction. We find that the eclipse caused local reductions of time-averaged surface flux of about 379 W m-2 (50 %) and 329 W m-2 (46 %) during the ~ 3 h course of the eclipse at the Casper and Columbia sites, respectively. We estimate that the Moon’s shadow caused a reduction of approximately 7 %–8 % in global average surface broadband SW radiation.
Johannes Stapf, André Ehrlich, Evelyn Jäkel, Christof Lüpkes, and Manfred Wendisch
Atmos. Chem. Phys., 20, 9895–9914, https://doi.org/10.5194/acp-20-9895-2020, https://doi.org/10.5194/acp-20-9895-2020, 2020
Nicholas D. Beres, Deep Sengupta, Vera Samburova, Andrey Y. Khlystov, and Hans Moosmüller
Atmos. Chem. Phys., 20, 6095–6114, https://doi.org/10.5194/acp-20-6095-2020, https://doi.org/10.5194/acp-20-6095-2020, 2020
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Brown carbon (BrC) aerosol can be produced by the smoldering combustion of peat, a wildland fuel common at high latitude, often adjacent to the cryosphere. However, little is known about how BrC deposition onto snow changes snow optical and radiative properties. Here, we artificially deposited BrC onto natural snow surfaces, monitored changes of the spectral surface albedo, characterized optical properties of deposited aerosol, and compared to modeled values of albedo and radiative forcing.
Margit Aun, Kaisa Lakkala, Ricardo Sanchez, Eija Asmi, Fernando Nollas, Outi Meinander, Larisa Sogacheva, Veerle De Bock, Antti Arola, Gerrit de Leeuw, Veijo Aaltonen, David Bolsée, Klara Cizkova, Alexander Mangold, Ladislav Metelka, Erko Jakobson, Tove Svendby, Didier Gillotay, and Bert Van Opstal
Atmos. Chem. Phys., 20, 6037–6054, https://doi.org/10.5194/acp-20-6037-2020, https://doi.org/10.5194/acp-20-6037-2020, 2020
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In 2017, new measurements of UV radiation started in Marambio, Antarctica, by the Finnish Meteorological Institute in collaboration with the Argentinian Servicio Meteorológico Nacional. The paper presents the results of UV irradiance measurements from March 2017 to March 2019, and it
compares them with those from 2000–2008 and also with UV measurements at other Antarctic stations. In 2017/2018, below average UV radiation levels were recorded due to favourable ozone and cloud conditions.
Mengqi Liu, Xiangdong Zheng, Jinqiang Zhang, and Xiangao Xia
Atmos. Chem. Phys., 20, 4415–4426, https://doi.org/10.5194/acp-20-4415-2020, https://doi.org/10.5194/acp-20-4415-2020, 2020
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This study uses 1 min radiation and lidar measurements at three stations over the Tibetan Plateau (TP) to parametrize downward longwave radiation (DLR) during summer months. Clear-sky DLR can be estimated from the best parametrization with a RMSE of 3.8 W m-2 and R2 > 0.98. Additionally cloud base height under overcast conditions is shown to play an important role in cloudy DLR parametrization, which is considered in the locally calibrated parametrization over the TP for the first time.
Stephan Nyeki, Stefan Wacker, Christine Aebi, Julian Gröbner, Giovanni Martucci, and Laurent Vuilleumier
Atmos. Chem. Phys., 19, 13227–13241, https://doi.org/10.5194/acp-19-13227-2019, https://doi.org/10.5194/acp-19-13227-2019, 2019
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The trends of meteorological parameters and surface downward shortwave radiation (DSR) and downward longwave radiation (DLR) were analysed at four stations (between 370 and 3580 m a. s. l.) in Switzerland for the 1996–2015 period. Trends in DSR and DLR were positive during cloudy as well as clear conditions. The trend due to the influence of clouds decreased in magnitude, which implies a reduction in cloud cover and/or a change towards a different cloud type over the four Swiss sites.
Christophe Bellisario, Helen E. Brindley, Simon F. B. Tett, Rolando Rizzi, Gianluca Di Natale, Luca Palchetti, and Giovanni Bianchini
Atmos. Chem. Phys., 19, 7927–7937, https://doi.org/10.5194/acp-19-7927-2019, https://doi.org/10.5194/acp-19-7927-2019, 2019
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We explore the possibility of inferring far-infrared downwelling radiances from mid-infrared observations to better constrain radiation schemes in climate models. Our results imply that while it is feasible to use this type of approach, the quality of the extension will be strongly dependent on the noise characteristics of the observations and on the accurate characterisation of the atmospheric state.
Germar Bernhard and Boyan Petkov
Atmos. Chem. Phys., 19, 4703–4719, https://doi.org/10.5194/acp-19-4703-2019, https://doi.org/10.5194/acp-19-4703-2019, 2019
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Solar radiation at ultraviolet, visible, and infrared wavelengths was measured during the total solar eclipse of 21 August 2017. Data were used to study the wavelength-dependent changes of solar radiation at Earth’s surface and to validate parameterizations of solar limb darkening (LD), which describes the change in the Sun’s brightness between its center and its edge. The study highlights the importance of the LD effect when calculating total ozone and aerosol optical depth during an eclipse.
Kaisa Lakkala, Alberto Redondas, Outi Meinander, Laura Thölix, Britta Hamari, Antonio Fernando Almansa, Virgilio Carreno, Rosa Delia García, Carlos Torres, Guillermo Deferrari, Hector Ochoa, Germar Bernhard, Ricardo Sanchez, and Gerrit de Leeuw
Atmos. Chem. Phys., 18, 16019–16031, https://doi.org/10.5194/acp-18-16019-2018, https://doi.org/10.5194/acp-18-16019-2018, 2018
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Solar UV irradiances were measured at Ushuaia (54° S) and Marambio (64° S) during 2000–2013. The measurements were part of the Antarctic NILU-UV network, which was maintained as a cooperation between Spain, Argentina and Finland. The time series of the network were analysed for the first time in this study. At both stations maximum UV indices and daily doses were measured when spring-time ozone loss episodes occurred. The maximum UV index was 13 and 12 in Ushuaia and Marambio, respectively.
Chunlüe Zhou, Yanyi He, and Kaicun Wang
Atmos. Chem. Phys., 18, 8113–8136, https://doi.org/10.5194/acp-18-8113-2018, https://doi.org/10.5194/acp-18-8113-2018, 2018
Pamela Trisolino, Alcide di Sarra, Fabrizio Anello, Carlo Bommarito, Tatiana Di Iorio, Daniela Meloni, Francesco Monteleone, Giandomenico Pace, Salvatore Piacentino, and Damiano Sferlazzo
Atmos. Chem. Phys., 18, 7985–8000, https://doi.org/10.5194/acp-18-7985-2018, https://doi.org/10.5194/acp-18-7985-2018, 2018
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The long-term (2002–2016) variability of global and diffuse PAR over the central Mediterranean is investigated based on measurements from Lampedusa. PAR modulates biological processes and this study provides useful insight into its variability. Seasonal and interannual variability of global and diffuse PAR is characterized and the effects of clouds are quantified. The analysis suggests that 77 % of the global PAR interannual variability may be ascribed to clouds.
Stelios Kazadzis, Dimitra Founda, Basil E. Psiloglou, Harry Kambezidis, Nickolaos Mihalopoulos, Arturo Sanchez-Lorenzo, Charikleia Meleti, Panagiotis I. Raptis, Fragiskos Pierros, and Pierre Nabat
Atmos. Chem. Phys., 18, 2395–2411, https://doi.org/10.5194/acp-18-2395-2018, https://doi.org/10.5194/acp-18-2395-2018, 2018
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The National Observatory of Athens has been collecting solar radiation, sunshine duration, and cloud and visibility data/observations since the beginning of the 20th century. In this work we present surface solar radiation data since 1953 and reconstructed data since 1900. We have attempted to show and discuss the long-term changes in solar surface radiation over Athens, Greece, using these unique datasets.
Klára Čížková, Kamil Láska, Ladislav Metelka, and Martin Staněk
Atmos. Chem. Phys., 18, 1805–1818, https://doi.org/10.5194/acp-18-1805-2018, https://doi.org/10.5194/acp-18-1805-2018, 2018
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In order to broaden the knowledge of long-term UV radiation variability, we have reconstructed and analyzed a 50-year-long UV radiation time series from Hradec Králové, Czech Republic. The UV radiation intensities increased greatly following the decline of ozone amounts in the 1980s and 1990s. High UV radiation doses were observed in days with low ozone amounts, clear or partly cloudy skies, or snow cover.
Janusz W. Krzyścin and Piotr S. Sobolewski
Atmos. Chem. Phys., 18, 1–11, https://doi.org/10.5194/acp-18-1-2018, https://doi.org/10.5194/acp-18-1-2018, 2018
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Maintaining homogeneity of long-term UV time series taken from various instruments and thus trend estimation are challenging tasks, especially for remote Arctic sites.
Highlights: method of the UV data homogenization is proposed to be used at any remote site. Past UV data built from satellite total O3 and ground-based sunshine duration. Yearly UV doses trendless in the southern Svalbard for 34-year period since 1983. Long-term cloud effects on UV more important than the ozone effects there.
Werner Eugster, Carmen Emmel, Sebastian Wolf, Nina Buchmann, Joseph P. McFadden, and Charles David Whiteman
Atmos. Chem. Phys., 17, 14887–14904, https://doi.org/10.5194/acp-17-14887-2017, https://doi.org/10.5194/acp-17-14887-2017, 2017
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The effects of penumbral shading of the solar eclipse of 20 March 2015 on near-surface meteorology across Switzerland (occultation 65.8–70.1 %) was investigated. Temperature effects at 184 weather stations are compared with temperature drops reported in the literature since 1834. A special focus is, however, put on wind direction effects observed at six flux sites (with 20 Hz data) and 165 meteorological stations (with 10 min resolution data). Results show the importance of local topography.
Axel Kreuter, Mario Blumthaler, Martin Tiefengraber, Richard Kift, and Ann R. Webb
Atmos. Chem. Phys., 17, 14353–14364, https://doi.org/10.5194/acp-17-14353-2017, https://doi.org/10.5194/acp-17-14353-2017, 2017
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We have done measurements of the sky's brightness at the Italian coast and show the influence of the underlying surface: looking towards the land, the sky can be up to 50 % brighter than opposite viewing directions towards the ocean as a result of higher land reflectivity. At low solar elevations, the specular reflection from the ocean, or sun glint, increases the zenith brightness. Understanding these effects requires a 3-D model and is important when retrieving, e.g., aerosol properties.
Reinout Boers, Theo Brandsma, and A. Pier Siebesma
Atmos. Chem. Phys., 17, 8081–8100, https://doi.org/10.5194/acp-17-8081-2017, https://doi.org/10.5194/acp-17-8081-2017, 2017
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In the Netherlands 9 W m−2 more solar radiation falls on the surface today than 50 years ago. Often this increase, which has also been detected in surrounding western Europe, has been attributed to decreasing air pollution due to improved regulatory practices. However, over the Netherlands clouds play an important but ambiguous role. Cloud cover has increased but have become optically thinner as well. Here, the impact of clouds on radiation is in fact more important than that of air pollution.
Jizeng Du, Kaicun Wang, Jiankai Wang, and Qian Ma
Atmos. Chem. Phys., 17, 4931–4944, https://doi.org/10.5194/acp-17-4931-2017, https://doi.org/10.5194/acp-17-4931-2017, 2017
Bomidi Lakshmi Madhavan, Hartwig Deneke, Jonas Witthuhn, and Andreas Macke
Atmos. Chem. Phys., 17, 3317–3338, https://doi.org/10.5194/acp-17-3317-2017, https://doi.org/10.5194/acp-17-3317-2017, 2017
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A method has been introduced to assess the representativeness of the time series of a point measurement compared to results for a larger area centered around the measurement location. This method allows one to determine the optimal accuracy that can be achieved for the validation of satellite products for a given pixel footprint, or the evaluation of an atmospheric model with a given grid-cell resolution.
Colette Brogniez, Frédérique Auriol, Christine Deroo, Antti Arola, Jukka Kujanpää, Béatrice Sauvage, Niilo Kalakoski, Mikko Riku Aleksi Pitkänen, Maxime Catalfamo, Jean-Marc Metzger, Guy Tournois, and Pierre Da Conceicao
Atmos. Chem. Phys., 16, 15049–15074, https://doi.org/10.5194/acp-16-15049-2016, https://doi.org/10.5194/acp-16-15049-2016, 2016
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The atmospheric ozone layer is changing, thus the UV radiation at the surface is changing. Due to both beneficial and adverse effects of UV on the biosphere, monitoring of UV is essential. Satellite sensors provide estimates of UV at the surface with a global coverage. Validation of satellite-sensor UV is therefore needed and this can be done by comparison with ground-based measurements. The present validation in three sites (midlatitude, tropical) shows that OMI and GOME-2 provide reliable UV.
Katsumasa Tanaka, Atsumu Ohmura, Doris Folini, Martin Wild, and Nozomu Ohkawara
Atmos. Chem. Phys., 16, 13969–14001, https://doi.org/10.5194/acp-16-13969-2016, https://doi.org/10.5194/acp-16-13969-2016, 2016
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Surface solar radiation observed in Japan generally shows a strong decline until the end of the 1980s and then a recovery up until around 2000. A substantial number of measurement stations are located close to populated areas and are speculated to have been influenced by air pollution. However, data obtained at 14 meteorological observatories suggest that the large decadal variations in surface solar radiation occur on a large scale and not limited to urban areas.
Jianping Guo, Yucong Miao, Yong Zhang, Huan Liu, Zhanqing Li, Wanchun Zhang, Jing He, Mengyun Lou, Yan Yan, Lingen Bian, and Panmao Zhai
Atmos. Chem. Phys., 16, 13309–13319, https://doi.org/10.5194/acp-16-13309-2016, https://doi.org/10.5194/acp-16-13309-2016, 2016
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The large-scale PBL climatology from sounding observations is still lacking in China. This work investigated the BLH characterization at diurnal, monthly and seasonal timescales throughout China, showing large geographic and meteorological dependences. BLH is, on average, negatively (positively) associated with the surface pressure and lower tropospheric stability (wind speed and temperature). Cloud tends to suppress the development of the PBL, which has implications for air quality forecasts.
Veronica Manara, Michele Brunetti, Angela Celozzi, Maurizio Maugeri, Arturo Sanchez-Lorenzo, and Martin Wild
Atmos. Chem. Phys., 16, 11145–11161, https://doi.org/10.5194/acp-16-11145-2016, https://doi.org/10.5194/acp-16-11145-2016, 2016
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This paper presents the temporal evolution of solar radiation over Italy for the 1959–2013 period and discusses possible reasons for differences between all-sky and clear-sky conditions in order to understand which part of the solar radiation variability depends on aerosols or clouds. The results give evidence of a relevant influence of both anthropogenic and natural aerosols on solar radiation long-term variability.
Weidong Guo, Xueqian Wang, Jianning Sun, Aijun Ding, and Jun Zou
Atmos. Chem. Phys., 16, 9875–9890, https://doi.org/10.5194/acp-16-9875-2016, https://doi.org/10.5194/acp-16-9875-2016, 2016
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Basic characteristics of land–atmosphere interactions at four neighboring sites with different underlying surfaces in southern China, a typical monsoon region, are analyzed systematically. Despite the same climate background, the differences in land surface characteristics like albedo and aerodynamic roughness length due to land use/cover change exert distinct influences on the surface radiative budget and energy allocation and result in differences of near-surface micrometeorological elements.
Fanny Finger, Frank Werner, Marcus Klingebiel, André Ehrlich, Evelyn Jäkel, Matthias Voigt, Stephan Borrmann, Peter Spichtinger, and Manfred Wendisch
Atmos. Chem. Phys., 16, 7681–7693, https://doi.org/10.5194/acp-16-7681-2016, https://doi.org/10.5194/acp-16-7681-2016, 2016
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Solar spectra of optical layer properties of cirrus have been derived from the first truly collocated airborne radiation measurements using an aircraft and a towed sensor platform. The measured layer properties differ slightly due to horizontal cirrus inhomogeneities and the influence of low-level water clouds. Applying a 1-D radiative transfer model sensitivity studies were performed. It was found that if a low-level cloud is not considered, the solar cooling of the cirrus is strongly overestimated.
Gerald M. Lohmann, Adam H. Monahan, and Detlev Heinemann
Atmos. Chem. Phys., 16, 6365–6379, https://doi.org/10.5194/acp-16-6365-2016, https://doi.org/10.5194/acp-16-6365-2016, 2016
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Increasing numbers of photovoltaic (PV) power systems call for the characterization of irradiance variability with very high spatiotemporal resolution. We use 1 Hz irradiance data recorded by as many as 99 pyranometers and show mixed sky conditions to differ substantially from clear and overcast skies. For example, the probabilities of strong fluctuations and their respective spatial autocorrelation structures are appreciably distinct under mixed conditions.
Adel Imamovic, Katsumasa Tanaka, Doris Folini, and Martin Wild
Atmos. Chem. Phys., 16, 2719–2725, https://doi.org/10.5194/acp-16-2719-2016, https://doi.org/10.5194/acp-16-2719-2016, 2016
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Systematic measurements of surface solar radiation revealed a worldwide decrease from the 1960s to the mid-1980s. The role of urbanization for this so called global dimming is still under debate. We developed a set of population-data based urbanization indicators and found no correlation between urbanization and global dimming for Europe and Japan, while an urbanization impact can't be precluded for Asia. It is thus called into question whether the global dimming was mainly a local phenomenon.
Ilias Fountoulakis, Alkiviadis F. Bais, Konstantinos Fragkos, Charickleia Meleti, Kleareti Tourpali, and Melina Maria Zempila
Atmos. Chem. Phys., 16, 2493–2505, https://doi.org/10.5194/acp-16-2493-2016, https://doi.org/10.5194/acp-16-2493-2016, 2016
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Short- and long-term variability of spectral UV irradiance at Thessaloniki, Greece, is discussed in association with changes in total ozone column, aerosols and cloudiness. The UV data set from two Brewer spectrophotometers is used for the analysis. For the entire period 1994–2014, positive, statistically significant increases of UV irradiance were found, mainly attributable to changes in aerosols. UV irradiance is mainly increased from 1994 to 2006 and remains relatively stable thereafter.
Costas A. Varotsos, Chris G. Tzanis, and Nicholas V. Sarlis
Atmos. Chem. Phys., 16, 2007–2011, https://doi.org/10.5194/acp-16-2007-2016, https://doi.org/10.5194/acp-16-2007-2016, 2016
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It has been recently reported that the current 2015–2016 El Niño could become "one of the strongest on record". To further explore this claim, we performed a new analysis that allows the detection of precursory signals of the strong El Niño events by using a recently developed non-linear dynamics tool. The analysis of the SOI time series shows that the 2015–2016 El Niño would be rather a "moderate to strong" or even a "strong” event and not "one of the strongest on record", as that of 1997–1998.
X. Guan, J. Huang, R. Guo, H. Yu, P. Lin, and Y. Zhang
Atmos. Chem. Phys., 15, 13777–13786, https://doi.org/10.5194/acp-15-13777-2015, https://doi.org/10.5194/acp-15-13777-2015, 2015
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Dynamical adjustment methodology has been applied to the raw surface air temperature and has successfully identified and separated the contribution of dynamically induced temperature (DIT) and radiatively forced temperature (RFT). It found that regional anthropogenic radiative forcing caused the enhanced warming in the semi-arid region, which may be closely associated with local human activities.
C.-M. Gan, J. Pleim, R. Mathur, C. Hogrefe, C. N. Long, J. Xing, D. Wong, R. Gilliam, and C. Wei
Atmos. Chem. Phys., 15, 12193–12209, https://doi.org/10.5194/acp-15-12193-2015, https://doi.org/10.5194/acp-15-12193-2015, 2015
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This study attempts to determine the consequences of the changes in tropospheric aerosol burden arising from substantial reductions in emissions of SO2 and NOx associated with control measures under the Clean Air Act especially on trends in solar radiation. Comparisons of model results with observations of aerosol optical depth, aerosol concentration, and radiation demonstrate that the coupled WRF-CMAQ model is capable of replicating the trends well even though it tends to underestimate the AOD.
G. Bernhard, A. Arola, A. Dahlback, V. Fioletov, A. Heikkilä, B. Johnsen, T. Koskela, K. Lakkala, T. Svendby, and J. Tamminen
Atmos. Chem. Phys., 15, 7391–7412, https://doi.org/10.5194/acp-15-7391-2015, https://doi.org/10.5194/acp-15-7391-2015, 2015
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Surface erythemal UV data from the Ozone Monitoring Instrument (OMI) are validated for high northern latitudes (Arctic and Scandinavia) using ground-based measurements. The bias in OMI data caused by incorrect assumptions of the surface albedo are quantified and the mechanism that causes this bias is discussed. Methods to improve the accuracy of OMI data products are presented.
S. R. Wilson
Atmos. Chem. Phys., 15, 7337–7349, https://doi.org/10.5194/acp-15-7337-2015, https://doi.org/10.5194/acp-15-7337-2015, 2015
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Measurements of the photolysis rates which drive production of OH from ozone are reported for Cape Grim, a "clean-air" site in the southern midlatitudes. This remote maritime site sits in the Southern Ocean, a region of the globe which is little studied. From the 6 years of data the dependence of this photolysis on solar zenith angle and stratospheric ozone is determined. Included with the reported values is an estimate of the uncertainties in these measurements.
C. A. Varotsos, S. Lovejoy, N. V. Sarlis, C. G. Tzanis, and M. N. Efstathiou
Atmos. Chem. Phys., 15, 7301–7306, https://doi.org/10.5194/acp-15-7301-2015, https://doi.org/10.5194/acp-15-7301-2015, 2015
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Varotsos et al. (Theor. Appl. Climatol., 114, 725–727, 2013) found that the solar ultraviolet (UV) wavelengths exhibit 1/f-type power-law correlations. In this study, we show that the residues of the spectral solar incident flux with respect to the Planck law over a wider range of wavelengths (i.e. UV-visible) have a scaling regime too.
P. Wang, M. Allaart, W. H. Knap, and P. Stammes
Atmos. Chem. Phys., 15, 4131–4144, https://doi.org/10.5194/acp-15-4131-2015, https://doi.org/10.5194/acp-15-4131-2015, 2015
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Short summary
A green light sensor has been developed at KNMI to measure actinic flux profiles together with an ozonesonde. The impact of clouds on the actinic flux is clearly detected. Good agreement is found between the DAK-simulated actinic flux profiles and the observations for single-layer clouds in fully overcast scenes. The instrument is suitable for operational balloon measurements because of its simplicity and low cost.
V. De Bock, H. De Backer, R. Van Malderen, A. Mangold, and A. Delcloo
Atmos. Chem. Phys., 14, 12251–12270, https://doi.org/10.5194/acp-14-12251-2014, https://doi.org/10.5194/acp-14-12251-2014, 2014
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Short summary
The roles of water, clouds and airborne dust in controlling the heating of the Sahara are uncertain, which has major implications for the West African monsoon. Observations from the Fennec project, with satellite data, show that total atmospheric water content provides a far stronger control on total radiative heating than dust does, but dust provides the stronger control on surface heating. Therefore major heating errors in global models are likely due to known errors in water transport.
The roles of water, clouds and airborne dust in controlling the heating of the Sahara are...
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