References

ACP

Atmospheric Chemistry and Physics

ACP

1680-7324

Copernicus GmbH

Göttingen, Germany

10.5194/acp-8-5033-2008

What can 14CO measurements tell us about OH?

Krol

M. C.

¹ ² ³ Meirink

J. F.

² Bergamaschi

⁴ Mak

J. E.

⁵ Lowe

⁶ Jöckel

⁷ Houweling

¹ ² Röckmann

Netherlands Institute for Space Research (SRON), Utrecht, The Netherlands

Institute for Marine and Atmospheric Research Utrecht (IMAU), Utrecht, The Netherlands

Wageningen University and Research Centre (WUR), Wageningen, The Netherlands

European Commission Joint Research Centre, Institute for Environment and Sustainability, Ispra, Italy

Institute for Terrestrial and Planetary Atmospheres, Stony Brook University, NY, USA

National Institute of Water and Atmospheric Research, Wellington, New Zealand

Max Planck Institute for Chemistry, Mainz, Germany

29 08 2008

8 16 5033 5044

This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

This article is available from http://www.atmos-chem-phys.net/8/5033/2008/acp-8-5033-2008.html

The full text article is available as a PDF file from http://www.atmos-chem-phys.net/8/5033/2008/acp-8-5033-2008.pdf

The possible use of 14CO measurements to constrain hydroxyl radical (OH) concentrations in the atmosphere is investigated. 14CO is mainly produced in the upper atmosphere from cosmic radiation. Measurements of 14CO at the surface show lower concentrations compared to the upper atmospheric source region, which is the result of oxidation by OH. In this paper, the sensitivity of 14CO mixing ratio surface measurements to the 3-D OH distribution is assessed with the TM5 model. Simulated 14CO mixing ratios agree within a few molecules 14CO cm−3 (STP) with existing measurements at five locations worldwide. The simulated cosmogenic 14CO distribution appears mainly sensitive to the assumed upper atmospheric 14C source function, and to a lesser extend to model resolution. As a next step, the sensitivity of 14CO measurements to OH is calculated with the adjoint TM5 model. The results indicate that 14CO measurements taken in the tropics are sensitive to OH in a spatially confined region that varies strongly over time due to meteorological variability. Given measurements with an accuracy of 0.5 molecules 14CO cm−3 STP, a good characterization of the cosmogenic 14CO fraction, and assuming perfect transport modeling, a single 14CO measurement may constrain OH to 0.2–0.3×106 molecules OH cm−3 on time scales of 6 months and spatial scales of 70×70 degrees (latitude×longitude) between the surface and 500 hPa. The sensitivity of 14CO measurements to high latitude OH is about a factor of five higher. This is in contrast with methyl chloroform (MCF) measurements, which show the highest sensitivity to tropical OH, mainly due to the temperature dependent rate constant of the MCF–OH reaction. A logical next step will be the analysis of existing 14CO measurements in an inverse modeling framework. This paper presents the required mathematical framework for such an analysis.

References 1

Bergamaschi, P., Frankenberg, C., Meirink, J. F., Krol, M., Dentener, F., Wagner, T., Platt, U., Kaplan, J. O., Körner, S., Heimann, M., Dlugokencky, E. J., and Goede, A.: Satellite chartography of atmospheric methane from SCIAMACHY onboard ENVISAT – 2: Evaluation based on inverse model simulations, J. Geophys. Res.-Atmos., 112, D02304 , doi:10.1029/2006JD007268, 2007.

Bergamaschi, P., Lowe, D. C., Manning, M. R., Moss, R., Bromley, T., and Clarkson, T. S.: Transects of atmospheric CO, CH4, and their isotopic composition across the Pacific: Shipboard measurements and validation of inverse models, J. Geophys. Res.-Atmos., 106, 7993–8011, 2001.

Bousquet, P., Hauglustaine, D. A., Peylin, P., Carouge, C., and Ciais, P.: Two decades of OH variability as inferred by an inversion of atmospheric transport and chemistry of methyl chloroform, Atmos. Chem. Phys., 5, 2635–2656, 2005.

Brenninkmeijer, C. A. M.: Measurement of the Abundance of (CO)-C-14 in the Atmosphere and the C-13 C-12 and O-18 O-16 Ratio of Atmospheric CO with Applications in New-Zealand and Antarctica, J. Geophys. Res.-Atmos., 98, 10 595–10 614, 1993.

Brenninkmeijer, C. A. M., Lowe, D. C., Manning, M. R., Sparks, R. J., and van Velthoven, P. F. J.: The C-13, C-14 and O-18 isotopic composition of CO, CH4, and CO2 in the higher southern latitudes lower stratosphere, J. Geophys. Res.-Atmos., 100, 26 163–26 172, 1995.

Brenninkmeijer, C. A. M., Manning, M. R., Lowe, D. C., Wallace, G., Sparks, R. J., and Volz Thomas, A.: Interhemispheric Asymmetry in OH Abundance Inferred from Measurements of Atmospheric (CO)-C-14, Nature, 356, 50–52, 1992.

Brühl, C. and Crutzen, P. J.: The MPIC 2-D model, NASA Ref. Publ., 1292, 103–104, 1993.

Ganzeveld, L., Lelieveld, J., and Roelofs, G. J.: A dry deposition parameterization for sulfur oxides in a chemistry and general circulation model, J. Geophys. Res.-Atmos., 103, 5679–5694, 1998.

Giering, R. and Kaminski, T.: Recipes for adjoint code construction, Acm Transactions on Mathematical Software, 24, 437–474, 1998.

Gros, V., Williams, J., Lawrence, M. G., von Kuhlmann, R., van Aardenne, J., Atlas, E., Chuck, A., Edwards, D. P., Stroud, V., and Krol, M.: Tracing the origin and ages of interlaced atmospheric pollution events over the tropical Atlantic Ocean with in situ measurements, satellites, trajectories, emission inventories, and global models, J. Geophys. Res.-Atmos., 109, D22306, doi:10.129/2004JD004846, 2004.

Gros, V., Williams, J., van Aardenne, J. A., Salisbury, G., Hofmann, R., Lawrence, M. G., von Kuhlmann, R., Lelieveld, J., Krol, M., Berresheim, H., Lobert, J. M., and Atlas, E.: Origin of anthropogenic hydrocarbons and halocarbons measured in the summertime European outflow (on Crete in 2001), Atmos. Chem. Phys., 3, 1223–1235, 2003.

Houweling, S., Kaminski, T., Dentener, F., Lelieveld, J., and Heimann, M.: Inverse modeling of methane sources and sinks using the adjoint of a global transport model, J. Geophys. Res., 104, 26 137–26 160, 1999.

Jöckel, P. and Brenninkmeijer, C. A. M.: The seasonal cycle of cosmogenic (CO)-C-14 at the surface level: A solar cycle adjusted, zonal-average climatology based on observations, J. Geophys. Res.-Atmos., 107, 4656, doi:10.1029/2001JD001104, 2002.

Jöckel, P., Brenninkmeijer, C. A. M., and Lawrence, M. G.: Atmospheric response time of cosmogenic (CO)-C-14 to changes in solar activity, J. Geophys. Res.-Atmos., 105, 6737–6744, 2000.

Jöckel, P., Brenninkmeijer, C. A. M., Lawrence, M. G., Jeuken, A. B. M., and van Velthoven, P. F. J.: Evaluation of stratosphere-troposphere exchange and the hydroxyl radical distribution in three-dimensional global atmospheric models using observations of cosmogenic (CO)-C-14, J. Geophys. Res.-Atmos., 107, 4446, doi:10.1029/2001JD001324, 2002.

Jöckel, P., Lawrence, M. G., and Brenninkmeijer, C. A. M.: Simulations of cosmogenic (CO)-C-14 using the three-dimensional atmospheric model MATCH: Effects of C-14 production distribution and the solar cycle, J. Geophys. Res.-Atmos., 104, 11 733–11 743, 1999.

Kaminski, T., Heimann, M., and Giering, T.: A coarse grid three dimensional global inverse model of the atmospheric transport, 1, Adjoint Model and Jacobian Matrix, J. Geophys. Res., 104, 18 535–18 553, 1999.

Krol, M., Houweling, S., Bregman, B., van den Broek, M., Segers, A., van Velthoven, P., Peters, W., Dentener, F., and Bergamaschi, P.: The two-way nested global chemistry-transport zoom model TM5: algorithm and applications, Atmos. Chem. Phys., 5, 417–432, 2005.

Krol, M. and Lelieveld, J.: Can the variability in tropospheric OH be deduced from measurements of 1,1,1-trichloroethane (methyl chloroform)?, J. Geophys. Res., 108, 4125, doi:10.1029/2002JD002423, 2003.

Lassey, K. R., Lowe, D. C., and Smith, A. M.: The atmospheric cycling of radiomethane and the "fossil fraction" of the methane source, Atmos. Chem. Phys., 7, 2141–2149, 2007.

Lelieveld, J., Brenninkmeijer, C. A. M., Joeckel, P., Isaksen, I. S. A., Krol, M. C., Mak, J. E., Dlugokencky, E., Montzka, S. A., Novelli, P. C., Peters, W., and Tans, P. P.: New Directions: watching over tropospheric hydroxyl (OH), Atmos. Environ., 40, 5741–5743, 2006.

Libby, W. F.: Atmospheric helium and radiocarbon from cosmic radiation, Phys. Rev., 69, 671–672, 1946.

Lingenfelter, R. E.: Production of carbon 14 by cosmic-ray neutrons, Rev. Geophys., 1, 35–55, 1963.

Lowe, D. C. and Allan, W.: A simple procedure for evaluating global cosmogenic C-14 production in the atmosphere using neutron monitor data, Radiocarbon, 44, 149–157, 2002.

MacKay, C., Pandow, M., and Wolfgang, R.: On the chemistry of natural radiocarbon, J. Geophys. Res., 68, 3929–3931, 1963.

Mak, J. E., Brenninkmeijer, C. A. M., and Manning, M. R.: Evidence for a Missing Carbon-Monoxide Sink Based on Tropospheric Measurements of (CO)-C-14, Geophys. Res. Lett., 19, 1467–1470, 1992.

Mak, J. E., Brenninkmeijer, C. A. M., and Tamaresis, J.: Atmospheric (CO)-C-14 Observations and Their Use for Estimating Carbon-Monoxide Removal Rates, J. Geophys. Res.-Atmos., 99, 22 915–22 922, 1994.

Mak, J. E., and Southon, J. R.: Assessment of tropical OH seasonality using atmospheric (CO)-C-14 measurements from Barbados, Geophys. Res. Lett., 25, 2801–2804, 1998.

Manning, M. R., Lowe, D. C., Moss, R. C., Bodeker, G. E., and Allan, W.: Short-term variations in the oxidizing power of the atmosphere, Nature, 436, 1001–1004, 2005.

Masarik, J. and Beer, J.: Simulation of particle fluxes and cosmogenic nuclide production in the Earth's atmosphere, J. Geophys. Res.-Atmos., 104, 12 099–12 111, 1999.

Meirink, J. F., Bergamaschi, P., and Krol, M. C.: Technical Note: Four-dimensional variational data assimilation for inverse modelling of atmospheric methane emissions: method and comparison with synthesis inversion, Atmos. Chem. Phys. Discuss., 8, 12 023–12 052, 2008.

Montzka, S. A., Spivakovsky, C. M., Butler, J. H., Elkins, J. W., Lock, L. T., and Mondeel, D. J.: New observational constraints for atmospheric hydroxyl on global and hemispheric scales, Science, 288, 500–503, 2000.

O'Brien, K., de la Zerda Lerner, A., Shea, M. A., and Smart, D. F.: The production of cosmogenic isotopes in the Earth's atmosphere and their inventories, in: The Sun in Time, edited by: Sonett, C. P., Giampapa, M. S., and Matthews, M. S., et al., Univ. of Arizona Press, Tucson, AZ, USA, 317–342, 1991.

Pandow, M., MacKay, C., and Wolfgang, R.: The reaction of atomic carbon with oxygen: Significance for the natural carbon cycle, J. Inorg. Nucl. Chem., 14, 153–158, 1960.

Prinn, R. G., Huang, J., Weiss, R. F., Cunnold, D. M., Fraser, P. J., Simmonds, P. G., McCulloch, A., Harth, C., Reimann, S., Salameh, P., O'Doherty, S., Wang, R. H. J., Porter, L. W., Miller, B. R., and Krummel, P. B.: Evidence for variability of atmospheric hydroxyl radicals over the past quarter century, Geophys. Res. Lett., 32, L07809, doi:10.1029/2004GL022228, 2005.

Prinn, R. G., Weiss, R. F., Miller, B. R., Huang, J., Alyea, F. N., Cunnold, D. M., Fraser, P. J., Hartley, D. E., and Simmonds, P. G.: Atmospheric Trends and Lifetime of CH3CCl3 and Global OH Concentrations, Science, 269, 187–192, 1995.

Quay, P., King, S., White, D., Brockington, M., Plotkin, B., Gammon, R., Gerst, S., and Stutsman, J.: Atmospheric (CO)-C-14: A tracer of OH concentration and mixing rates, J. Geophys. Res.-Atmos., 105, 15 147–15 166, 2000.

Röckmann, T., Jöckel, P., Gros, V., Braunlich, M., Possnert, G., and Brenninkmeijer, C. A. M.: Using C-14, C-13, O-18 and O-17 isotopic variations to provide insights into the high northern latitude surface CO inventory, Atmos. Chem. Phys., 2, 147–159, 2002.

Spivakovsky, C. M., Logan, J. A., Montzka, S. A., Balkanski, Y. J., Foreman-Fowler, M., Jones, D. B. A., Horowitz, L. W., Fusco, A. C., Brenninkmeijer, C. A. M., Prather, M. J., Wofsy, S. C., and McElroy, M. B.: Three-dimensional climatological distribution of tropospheric OH: Update and evaluation, J. Geophys. Res.-Atmos., 105, 8931–8980, 2000.

Usoskin, I. G., Alanko-Huotari, K., Kovaltsov, G. A., and Mursula, K.: Heliospheric modulation of cosmic rays: Monthly reconstruction for 1951–2004, J. Geophys. Res.-Space Phys., 110, A12108, doi:10.1029/2005JA011250, 2005.

Volz, A., Ehhalt, D. H., and Derwent, R. G.: Seasonal and latitudinal variation of $^14$CO and the tropospheric concentration of OH radicals, J. Geophys. Res., 86, 5163–5171, 1981.