ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-12-12183-2012 Quantifying the deep convective temperature signal within the tropical tropopause layer (TTL) Paulik L. C. 1 Birner T. 1 Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA 21 12 2012 12 24 12183 12195 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/12/12183/2012/acp-12-12183-2012.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/12/12183/2012/acp-12-12183-2012.pdf

Dynamics on a vast range of spatial and temporal scales, from individual convective plumes to planetary-scale circulations, play a role in driving the temperature variability in the tropical tropopause layer (TTL). Here, we aim to better quantify the deep convective temperature signal within the TTL using multiple datasets. First, we investigate the link between ozone and temperature in the TTL using the Southern Hemisphere Additional Ozonesondes (SHADOZ) dataset. Low ozone concentrations in the TTL are indicative of deep convective transport from the boundary layer. We confirm the usefulness of ozone as an indicator of deep convection by identifying a typical temperature signal associated with reduced ozone events: an anomalously warm mid to upper troposphere and an anomalously cold upper TTL. We quantify these temperature signals using two diagnostics: (1) the "ozone minimum" diagnostic, which has been used in previous studies and identifies the upper tropospheric minimum ozone concentration as a proxy for the level of main convective outflow; and (2) the "ozone mixing height", which we introduce in order to identify the maximum altitude in a vertical ozone profile up to which reduced ozone concentrations, typical of transport from the boundary layer are observed. Results indicate that the ozone mixing height diagnostic better separates profiles with convective influence than the ozone minimum diagnostic. Next, we collocate deep convective clouds identified by CloudSat 2B-CLDCLASS with temperature profiles based on Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) Global Position System (GPS) radio occultations. We find a robust large-scale deep convective TTL temperature signal, that is persistent in time. However, it is only the convective events that penetrate into the upper half of the TTL that have a significant impact on TTL temperature. A distinct seasonal difference in the spatial scale and the persistence of the temperature signal is identified. Deep-convective cloud top heights are on average found to be well described by the level of neutral buoyancy.

 References Anthes, R A., Kallberg, P W., Simmons, A J., Andrae, U., Bechtold, P., Costa, V D., M. Fiorino, M., Gibson, J K., Haseler, J., Hernandez, A., Kelly, G A., Li, X., Onogi, K., Saarinen, S., Sokka, N., Allan, R P., Andersson, E., Arpe, K., Balmaseda, M A., Beljaars, A. C M., Berg, L. V D., Bidlot, J., Bormann, N., Caires, S., Chevallier, F., Dethof, A., Dragosavac, M., Fisher, M., Fuentes, M., Hagemann, S., Holm, E., Hoskins, B J., Isaksen, L., Janssen, P. A. E M., Jenne, R., McNally, A P., Mahfouf, J.-F., Morcrette, J.-J., Rayner, N A., Saunders, R W., Simon, P., Sterl, A., Trenberth, K E., Untch, A., Vasiljevic, D., Viterbo, P., and Woollen, J.: The COSMIC/FORMOSAT-3 mission: Early results, B. AM. Meteorol. Soc., 89, 313–333, 2008. Brewer, A W.: Evidence for a world circulation provided by the measurements of helium and water vapor distribution in the stratosphere, Q. J. Roy. Meteor. Soc., 75, 351–363, 1949. Chae, J. H., Wu, D. L., Read, W. G., and Sherwood, S. C.: The role of tropical deep convective clouds on temperature, water vapor, and dehydration in the tropical tropopause layer (TTL), Atmos. Chem. Phys., 11, 3811–3821, http://dx.doi.org/10.5194/acp-11-3811-2011doi:10.5194/acp-11-3811-2011, 2011. Fierro, A O., Simpson, J., LeMone, M A., Straka, J M., and Smull, B F.: On how hot towers fuel the Hadley cell: An observational and modeling study of line-organized convection in the equatorial trough from TOGA COARE, J. Atmos. Sci., 66, 2730–2746, 2009. Folkins, I. and Martin, R V.: The vertical structure of tropical convection and its impact on the budgets of water vapor and ozone, J. Atmos. Sci., 62, 1560–1573, 2005. Folkins, I., Loewenstein, M., Podolske, J., Oltmans, S J., and Proffitt, M.: A barrier to vertical mixing at 14 km in the tropics: Evidence from ozonesondes and aircraft measurements, J. Geophys. Res., D18, 22095–22102, 1999. Folkins, I., Braun, C., Thompson, A M., and White, J.: Tropical ozone as indicator of deep convection, J. Geophys. Res., 107, 4184, http://dx.doi.org/10.1029/2001JD001178doi:10.1029/2001JD001178, 2002. Folkins, I., Fueglistaler, S., Lesins, G., and Mitovski, T.: A Low-Level Circulation in the Tropics, J. Atmos. Sci., 65, 1019–1034, 2008. Fueglistaler, S., Bonazzola, M., Haynes, P H., and Peter, T.: Stratospheric water vapor predicted from Lagrangian temperature history of air entering the stratosphere in the tropics, J. Geophys. Res., 110, D08107, http://dx.doi.org/10.1029/2004JD005516doi:10.1029/2004JD005516, 2005. Fueglistaler, S., Dessler, A E., Dunkerton, T J., Folkins, I., Fu, Q., and Mote, P W.: Tropical tropopause layer, Rev. Geophys., 47, RG1004, http://dx.doi.org/10.1029/2008RG000267doi:10.1029/2008RG000267, 2009. Gettelman, A. and Birner, T.: Insights into Tropical Tropopause Layer processes using global models, J. Geophys. Res., 112, D23104, http://dx.doi.org/10.1029/2007JD008945doi:10.1029/2007JD008945, 2007. Gettelman, A. and Forster, P. M. d F.: A climatology of the tropical tropopause layer, J. Meteor. Soc. Jpn., 80, 911–924, 2002. Holloway, C E. and Neelin, J D.: The convective cold top and quasi equilibrium, J. Atmos. Sci., 64, 1467–1487, 2007. Holton, J R. and Gettelman, A.: Horizontal transport and the dehydration of the stratosphere, Geophys. Res. Lett., 28, 2799–2802, 2001. Johnson, R H. and Kriete, D C.: Thermodynamic and circulation characteristics of winter monsoon tropical mesoscale convection, Mon. Weather Rev., 110, 1898–1911, 1982. Kiladis, G N., Straub, K H., Reid, G C., and Gage, K S.: Aspects of interannual and intraseasonal variability of the tropopause and lower stratosphere, Q. J. Roy. Meteor. Soc., 127, 1961–1983, 2001. Kiladis, G N., Straub, K H., and Haertel, P T.: Zonal and vertical structure of the Madden-Julian oscillation, J. Atmos. Sci., 62, 2790–2809, 2005. Kiladis, G N., Wheeler, M C., Haertel, P T., Straub, K H., and Roundy, P E.: Convectively coupled equatorial waves, Rev. Geophys., 47, RG2003, http://dx.doi.org/10.1029/2008RG000266doi:10.1029/2008RG000266, 2009. Kim, J. and Son, S.-W.: Tropical Cold-Point Tropopause: Climatology, Seasonal Cycle, and Intraseasonal Variability Derived from COSMIC GPS Radio Occultation Measurements, J. Climate, 25, 5343–5360, 2012. Kley, D., Crutzen, P J., Smit, H. G J., Vömel, H., Oltmans, S J., Grassl, H., and Ramanathan, V.: Observations of Near-Zero Ozone Concentrations over the Convective Pacific: Effects on Air Chemistry, Science, 274, 230–233, 1996. Komhyr, W D., Barnes, R., Brothers, G., Lathrop, J., and Opperman, D.: Electrochemical concentration cell ozonesonde performance evaluation during STOIC 1989, J. Geophys. Res., 100, 9231–9244, 1995. Kursinski, E R., Hajj, G A., Bertiger, W I., Leroy, S S., Meehan, T K., Romans, L J., Schofield, J T., McCleese, D J., Melbourne, W G., Thornton, C L., Yunck, T P., Eyre, J R., and Nagatani, R N.: Initial results of radio occultation observations of the Earth's atmosphere using the Global Positioning System, Science, 271, 1107–1110, 1996. Kursinski, E R., Haij, G A., Schofield, J T., Linfield, R P., and Hardy, K R.: Observing the Earth's atmosphere with radio occultation measurements using the Global Positioning System, J. Geophys. Res., 102, 23429–23465, 1997. Liu, C. and Zipser, E J.: Global distribution of convection penetrating the tropical tropopause, J. Geophys. Res., 110, D23104, http://dx.doi.org/10.1029/2005JD006063doi:10.1029/2005JD006063, 2005. Ma, D. and Kuang, Z.: Modulation of radiative heating by the Madden Julian Oscillation and convectively coupled Kelvin waves as observed by CloudSat, Geophys. Res. Lett., 38, L21813, http://dx.doi.org/10.1029/2011GL049734doi:10.1029/2011GL049734, 2011. Mitovski, T., Folkins, I., von Salzen, K., and Sigmond, M.: Temperature, Relative Humidity, and Divergence Response to High Rainfall Events in the Tropics: Observations and Models, J. Climate, 23, 3613–3625, 2010. Mote, P W., Rosenlof, K H., McIntyre, M E., Carr, E S., Gille, J G., Holton, J R., Kinnersley, J S., Pumphrey, H C., Russell, J M., I., and Waters, J W.: An atmospheric tape recorder: The imprint of tropical tropopause temperatures on stratospheric water vapor, J Geophys. Res., 101, 3989–4006, 1996. Norton, W A.: Tropical Wave Driving of the Annual Cycle in Tropical Tropopause Temperatures. Part II: Model Results, J. Atmos. Sci., 63, 1420–1431, 2006. Paulik, L C.: Quantifying deep convective influence on the tropical tropopause layer (TTL), Master's thesis, Department of Atmospheric Science, Colorado State University, 122 pp., 2011. Randel, W J. and Thompson, A M.: Interannual variability and trends in tropical ozone derived from SAGE II satellite data and SHADOZ ozonesondes, J. Geophys. Res., 116, D07303, http://dx.doi.org/10.1029/2010JD015195doi:10.1029/2010JD015195, 2011. Randel, W J. and Wu, F.: Thermal variability of the tropical tropopause region derived from GPS/MET observations, J. Geophys. Res., 108, 4024, http://dx.doi.org/10.1029/2002JD002595doi:10.1029/2002JD002595, 2003. Romps, D M. and Kuang, Z.: Do Undiluted Convective Plumes Exist in the Upper Tropical Troposphere?, J. Atmos. Sci., 67, 468–484, 2010. Sassen, K. and Wang, Z.: Classifying clouds around the globe with CloudSat radar: 1-year of results, Geophys. Res. Lett., 35, L04805, http://dx.doi.org/10.1029/2007GL032591doi:10.1029/2007GL032591, 2008. Sherwood, S C. and Wahrlich, R.: Observed Evolution of Tropical Deep Convective Events and Their Environment, Mon. Weather Rev., 127, 1777–1795, 1999. Sherwood, S C., Horinouchi, T., and Zeleznik, H.: Convective impact on temperatures observed near the tropical tropopause, J. Atmos. Sci., 60, 1847–1856, 2003. Solomon, S., Portmann, R W., Sasaki, T., Hofmann, D J., and Thompson, D. W J.: Four decades of ozonesonde measurements over Antarctica, J Geophys. Res., 110, D21311, http://dx.doi.org/10.1029/2005JD005917doi:10.1029/2005JD005917, 2005. Stephens, G L., Vane, D G., Boain, R J., Mace, G G., Sassen, K., Wang, Z., Illingworth, A J., O'Connor, E J., Rossow, W B., Durden, S L., Miller, S D., Austin, R T., Benedetti, A., Mitrescu, C., and The CloudSat Science Team: The CloudSat Mission and the A-Train, B. Am. Meteorol. Soc., 83, 1771–1790, 2002. Takahashi, H. and Luo, Z.: Where is the level of neutral buoyancy for deep convection?, Geophys. Res. Lett., 39, L15809, http://dx.doi.org/10.1029/2012GL052638doi:10.1029/2012GL052638, 2012. Thompson, A M., Witte, J C., McPeters, R D., Oltmans, S J., Schmidlin, F J., Logan, J A., Fujiwara, M., Kirchhoff, V. W. J H., Posny, F., Coetzee, G. J R., Hoegger, B., Kawakami, S., Ogawa, T., Johnson, B J., Vomel, H., and Labow, G.: Southern Hemisphere Additional Ozonesondes (SHADOZ) 1998–2000 tropical ozone climatology 1. Comparison with Total Ozone Mapping Spectrometer (TOMS) and ground-based measurements, J. Geophys. Res., 108, 8238, http://dx.doi.org/10.1029/2001JD000967doi:10.1029/2001JD000967, 2003a. Thompson, A M., Witte, J C., Oltmans, S J., Schmidlin, F J., Logan, J A., Fujiwara, M., Kirchhoff, V. W. J H., Posny, F., Coetzee, G. J R., Hoegger, B., Kawakami, S., Ogawa, T., Fortuin, J. P F., and Kelder, H M.: Southern Hemisphere Additional Ozonesondes (SHADOZ) 1998–2000 tropical ozone climatology 2. Tropospheric variability and the zonal wave-one, J. Geophys. Res., 108, 8241, http://dx.doi.org/10.1029/2002JD002241doi:10.1029/2002JD002241, 2003b. Thompson, A M., Allen, A L., Lee, S., Miller, S K., and Witte, J C.: Gravity and Rossby wave signatures in the tropical troposphere and lower stratosphere based on Southern Hemisphere Additional Ozonesondes (SHADOZ), J. Geophys. Res., 116, D05302, http://dx.doi.org/10.1029/2009JD013429doi:10.1029/2009JD013429, 2011. Zeng, Z., Ho, S.-P., Sokolovskiy, S., and Kuo, Y.-H.: Structural evolution of the Madden-Julian Oscillation from COSMIC radio occultation data, J. Geophys. Res., 117, D22108, http://dx.doi.org/10.1029/2012JD017685doi:10.1029/2012JD017685, 2012.