Atmospheric Chemistry and Physics www.atmos-chem-phys.net 1680-7316 1680-7324 9 15 2009 10.5194/acp-9-5847-2009 http://www.atmos-chem-phys.net/9/5847/2009/ http://www.atmos-chem-phys.net/9/5847/2009/acp-9-5847-2009.html http://www.atmos-chem-phys.net/9/5847/2009/acp-9-5847-2009.pdf 5847 5864 2009-08-12 A statistical analysis of the influence of deep convection on water vapor variability in the tropical upper troposphere J. S. Wright jw2519@columbia.edu R. Fu A. J. Heymsfield Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, USA Jackson School of Geosciences, University of Texas, Austin, TX, USA National Center for Atmospheric Research, Boulder, CO, USA The factors that control the influence of deep convective detrainment on water vapor in the tropical upper troposphere are examined using observations from multiple satellites in conjunction with a trajectory model. Deep convection is confirmed to act primarily as a moisture source to the upper troposphere, modulated by the ambient relative humidity (RH). Convective detrainment provides strong moistening at low RH and offsets drying due to subsidence across a wide range of RH. Strong day-to-day moistening and drying takes place most frequently in relatively dry transition zones, where between 0.01% and 0.1% of Tropical Rainfall Measuring Mission Precipitation Radar observations indicate active convection. Many of these strong moistening events in the tropics can be directly attributed to detrainment from recent tropical convection, while others in the subtropics appear to be related to stratosphere-troposphere exchange. The temporal and spatial limits of the convective source are estimated to be about 36–48 h and 600–1500 km, respectively, consistent with the lifetimes of detrainment cirrus clouds. Larger amounts of detrained ice are associated with enhanced upper tropospheric moistening in both absolute and relative terms. In particular, an increase in ice water content of approximately 400% corresponds to a 10–90% increase in the likelihood of moistening and a 30–50% increase in the magnitude of moistening. Aumann,~H H., Chahine,~M T., Gautier,~C., Goldberg,~M D., Kalnay,~E., McMillin,~L M., Revercomb,~H., Rosenkranz,~P W., Smith,~W L., Staelin,~D H., Strow,~L L., and Susskind,~J.: AIRS/AMSU/HSB on the Aqua mission: design, science objectives, data products, and processing systems, IEEE T. Geosci. Remote, 41, 253–264, 2003. Chaudhuri,~P. and Marron,~J S.: SiZer for exploration of structure in curves, J. Am. Stat. Assoc., 94, 807–823, 1999. Deierling,~W., Petersen,~W A., Latham,~J., Ellis,~S., and Christian,~H J.: The relationship between lightning activity and ice fluxes in thunderstorms, J. Geophys. Res., 113, D15210, \doi10.1029/2007JD009700, 2008. Del~Genio,~A D., Kovari,~W., Yao,~M.-S., and Jonas,~J.: Cumulus microphysics and climate sensitivity, J. Climate, 18, 2376–2386, 2005. Dessler,~A E. and Minschwaner,~K.: An analysis of the regulation of tropical tropospheric water vapor, J. Geophys. Res., 112, D10120, \doi10.1029/2006JD007683, 2007. Dessler,~A E. and Sherwood,~S C.: Simulations of tropical upper tropospheric humidity, J. Geophys. Res., 105, 20 155–20 163, 2000. Divakarla,~M G., Barnet,~C D., Goldberg,~M D., McMillin,~L M., Maddy,~E., Wolf,~W., Zhou,~L., and Liu,~X.: Validation of Atmospheric Infrared Sounder temperature and water vapor retrievals with matched radiosonde measurements and forecasts, J. Geophys. Res., 111, D09515, \doi10.1029/2005JD006116, 2006. Emanuel,~K.: Atmospheric Convection, Oxford University Press, New York, USA, 1994. Emanuel,~K A. and Pierrehumbert,~R T.: Microphysical and dynamical control of tropospheric water vapor, in: Clouds, Chemistry, and Climate, edited by: Crutzen,~P J. and Ramanathan,~V., Springer, New York, USA, 17–28, 1995. Folkins,~I., Kelly,~K K., and Weinstock,~E M.: A~simple explanation for the increase in relative humidity between 11 and 14 km in the tropics, J. Geophys. Res., 107(D23), 4736, doi:10.1029/2002JD002185, 2002. Fu,~R., Del~Genio,~A D., and Rossow,~W B.: Influence of ocean surface conditions on atmospheric vertical thermodynamic structure and deep convection, J. Climate, 7, 1092–1108, 1994. Fuenzalida,~H A., Sánchez,~R., and Garreaud,~R D.: A~climatology of cutoff lows in the Southern Hemisphere, J. Geophys. Res., 110, D18101, \doi10.1029/2005JD005934, 2005. Garreaud,~R D. and Wallace,~J M.: Summertime incursions of midlatitude air into subtropical and tropical South America, Mon. Weather Rev., 126, 2713–2733, 1998. Gettelman,~A., Randel,~W J., Wu,~F., and Massie,~S T.: Transport of water vapor in the tropical tropopause layer, Geophys. Res. Lett., 29(1), 1009, \doi10.1029/2001GL013818, 2002. Gettelman,~A., Weinstock,~E M., Fetzer,~E J., Irion,~F W., Eldering,~A E., Richard,~E C., Rosenlof,~K H., Thompson,~T L., Pittman,~J V., Webster,~C R., and Herman,~R L.: Validation of Aqua satellite data in the upper troposphere and lower stratosphere with in situ aircraft instruments, Geophys. Res. Lett., 31, L22107, \doi10.1029/2004GL020730, 2004. Gettelman,~A., Collins,~W D., Fetzer,~E J., Eldering,~A E., Irion,~F W., Duffy,~P B., and Bala,~G.: Climatology of upper-tropospheric relative humidity from the Atmospheric Infrared Sounder and implications for climate, J. Climate, 19, 6104–6121, \doi10.1175/JCLI3956.1, 2006. Hagan,~D E., Webster,~C R., Farmer,~C B., May,~R D., Herman,~R L., Weinstock,~E M., Christensen,~L E., Lait,~L R., and Newman,~P A.: Validating AIRS upper atmosphere water vapor retrievals using aircraft and balloon in situ measurements, Geophys. Res. Lett., 31, L21103, \doi10.1029/2004GL020302, 2004. Heymsfield,~A J., and Donner,~L.: A scheme for parameterizing ice-cloud water content in general circulation models, J. Atmos. Sci., 47, 1865–1877, 1996. Heymsfield,~A J., Bansemer,~A., Schmitt,~C., Twohy,~C., and Poellot,~M R.: Effective ice particle densities derived from aircraft data, J. Atmos. Sci., 61, 982–1003, 2004. Heymsfield,~A J., Bansemer,~A., Durden,~S L., Herman,~R L., and Bui,~T.: Ice microphysics observations in hurricane Humberto: Comparison with non-hurricane-generated ice cloud layers, J. Atmos. Sci., 63, 288–308, \doi10.1175/JAS3603.1, 2006. Heymsfield,~G M., Geerts,~B., and Tian,~L.: TRMM Precipitation Radar reflectivity profiles compared with high-resolution airborne and ground-based measurements, J. Appl. Meteorol., 39, 2080–2102, \doi10.1175/1520-0450(2001)040<2080:TPRRPA>2.0.CO;2, 2000. Kentarchos,~A S., Davies,~T D., and Terefos,~C S.: A~low latitude stratospheric intrusion associated with a cut-off low, Geophys. Res. Lett., 25, 67–70, 1998. Kummerow,~C., Barnes,~W., Kozu,~T., Shuie,~J., and Simpson,~J.: The Tropical Rainfall Measuring Mission (TRMM) sensor package, J. Atmos. Ocean. Tech., 15, 809–817, 1998. Lane,~T P., Reeder,~M J., and Clark,~T L.: Numerical modeling of gravity wave generation by deep tropical convection, J. Atmos. Sci., 58, 1249–1274, 2001. Luo,~Z. and Rossow,~W B.: Characterizing tropical cirrus life cycle, evolution and interaction with upper-tropospheric water vapor using Lagrangian trajectory analysis of satellite observations, J. Climate, 17, 4541–4563, 2004. Luo,~Z., Kley,~D., Johnson,~R H., and Smit,~H.: Ten years of measurements of tropical upper-tropospheric water vapor by MOZAIC: Part I: variability, transport, and relation to deep convection, J. Climate, 20, 418–435, \doi10.1175/JCLI3997.1, 2007. McCormack,~J P., Fu,~R., and Read,~W G.: The influence of convective outflow on mixing ratios in the tropical upper troposphere: and analysis based on UARS MLS measurements, J. Atmos. Sci., 24, 241–259, 2000. Nesbitt,~S W. and Zipser,~E J.: The diurnal cycle of rainfall and convective intensity according to three years of TRMM measurements, J. Climate, 16, 1456–1475, \doi10.1175/1520-0442(2003)016<1456:TDCORA>2.0.CO;2, 2003. Petersen,~W A. and Rutledge,~S A.: Regional variability in tropical convection: Observations from TRMM, J. Climate, 14, 3566–3586, 2001. Pierrehumbert,~R T.: Thermostats, radiator fins, and the local runaway greenhouse, J. Atmos. Sci., 52, 1784–1806, 1995. Pierrehumbert,~R T.: Lateral mixing as a source of subtropical water vapor, Geophys. Res. Lett., 25, 151–154, 1998. Protat,~A., Delano\"e,~J., Bouniol,~D., Heymsfield,~A J., Bansemer,~A., and Brown,~P.: Evaluation of ice water content retrievals from cloud radar reflectivity and temperature using a large airborne in situ microphysical database, J. Appl. Meteorol. Clim., 46, 557–572, \doi10.1175/JAM2488.1, 2007. Randall,~D A., Wood,~R A., Bony,~S., Colman,~R., Fichefet,~T., Fyfe,~J., Kattsov,~V., Pitman,~A., Shukla,~J., Srinivasan,~J., Stouffer,~R J., Sumi,~A., and Taylor,~K E.: Climate Models and Their Evaluation, in: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Solomon,~S., Qin,~D., Manning,~M., Chen,~Z., Marquis,~M., Averyt,~K B., Tignor,~M., and Miller,~H L., Cambridge University Press, Cambridge, UK and New York, NY, USA, 589–662, 2007. Rapp,~A D., Kummerow,~C., Berg,~W., and Griffith,~B.: An evaluation of the proposed mechanism of the adaptive infrared iris hypothesis using TRMM VIRS and PR measurements, J. Climate, 18, 4185–4194, \doi10.1175/JCLI3528.1, 2005. Rosenfield,~J E., Newman,~P A., and Schoeberl,~M R.: Computations of diabatic descent in the stratospheric polar vortex, J. Geophys. Res., 99, 16677–16689, 1994. Ryoo,~J.-M., Waugh,~D W., and Gettelman,~A.: Variability of subtropical upper tropospheric humidity, Atmos. Chem. Phys., 8, 2643–2655, 2008. Salathé,~E P. and Hartmann,~D L.: A~trajectory analysis of tropical upper-tropospheric moisture and convection, J. Climate, 10, 2533–2547, 1997. Schoeberl,~M R. and Sparling,~L.: Trajectory modeling, in: Diagnostic Tools in Atmospheric Physics, vol 124, Proceedings of the International School of Physics Enrico Fermi, edited by: Fiocco,~G. and Visconti,~G., 289–306, IOS Press, Amsterdam, The Netherlands, 1995. Sherwood,~S C.: Maintenance of the free-tropospheric tropical water vapor distribution. Part II: Simulation by large-scale advection, J. Climate, 9, 2919–2934, 1996. Sherwood,~S C.: A~microphysical connection among biomass burning, cumulus clouds, and stratospheric moisture, Science, 295, 1272–1275, 2002. Shine,~K P. and Sinha,~A.: Sensitivity of the Earth's climate to height-dependent changes in the water vapour mixing ratio, Nature, 354, 382–384, \doi10.1038/354382a0, 1991. Soden,~B J.: The impact of tropical convection and cirrus on upper tropospheric humidity: A~Lagrangian analysis of satellite measurements, Geophys. Res. Lett., 31, L20104, \doi10.1029/2004GL020980, 2004. Soden,~B J. and Fu,~R.: A~seasonal analysis of deep convection, upper-tropospheric humidity, and the greenhouse effect, J. Climate, 8, 2333–2351, 1995. Soden,~B J. and Held,~I M.: An assessment of climate feedbacks in coupled ocean-atmosphere models, J. Climate, 19, 3354–3360, \doi10.1175/JCLI3799.1, 2006. Spencer,~R W. and Braswell,~W D.: How dry is the tropical free troposphere? Implications for global warming theory, B. Am. Meteor. Soc., 78, 1097–1106, 1997. Sprenger,~M., Maspoli,~M C., and Wernli, H.: Tropopause folds and crosstropopause transport: a global investigation based upon ECMWF analyses for the time period March 2000 till February 2001, J. Geophys. Res., 108, \doi10.1029/2002JD002587, 2003. Stephens,~G L. and Greenwald,~T J.: The Earth's radiation budget and its relation to atmospheric hydrology: 2. Observations of cloud effects, J. Geophys. Res., 96, 15325–15340, 1990. Sun,~D.-Z. and Lindzen,~R S.: Distribution of tropical tropospheric water vapor, J. Atmos. Sci., 50, 1643–1660, 1993. Susskind,~J., Barnet,~C D., and Blaisdell,~J M.: Retrieval of atmospheric and surface parameters from AIRS/AMSU/HSB data in the presence of clouds, IEEE T. Geosci. Remote, 41, 390–409, 2003. Swinbank,~R. and O'Neill,~A.: A~stratosphere-troposphere data assimilation system, Mon. Weather Rev., 122, 686–702, 1994. Waliser,~D E., Li,~J.-L F., Woods,~C P., Austin,~R T., Bacmeister,~J., Chern,~J., Del~Genio,~A., Jiang,~J H., Kuang,~Z., Meng,~H., Minnis,~P., Platnick,~S., Rossow,~W B., Stephens,~G L., Sun-Mack,~S., Tao,~W.-K., Tompkins,~A M., Vane,~D G., Walker,~C., and Wu,~D.: Cloud ice: A climate model challenge with signs and expectations of progress, J. Geophys. Res., 114, D00A21, \doi10.1029/2008JD010015, 2009. Waugh,~D W.: Impact of potential vorticity intrusions on subtropical upper tropospheric humidity, J. Geophys. Res., 110, D11305, \doi10.1029/2004JD005664, 2005. Waugh,~D W. and Polvani,~L M.: Climatology of intrusions into the tropical upper troposphere, Geophys. Res. Lett., 27, 3857–3860, 2000. Wernli,~H.: A~Lagrangian-based analysis of extratropical cyclones. II: A~detailed case-study, Q. J. Roy Meteor. Soc., 123, 1677–1706, 1997.