Will moist convection be stronger in a warmer climate?

[1] The intensity of moist convection is an important diagnostic of climate change not currently predicted by most climate models. We show that a simple estimate of the vertical velocity of convective updrafts in a global climate model reproduces observed land-ocean differences in convective intensity. Changes in convective intensity in a doubled CO2 simulation are small because the tropical lapse rate tends to follow a moist adiabatic profile. However, updrafts strengthen by ∼1 m s−1 with warming in the lightning-producing regions of continental convective storms, primarily due to an upward shift in the freezing level. For the western United States, drying in the warmer climate reduces the frequency of lightning-producing storms that initiate forest fires, but the strongest storms occur 26% more often. For the central-eastern United States, stronger updrafts combined with weaker wind shear suggest little change in severe storm occurrence with warming, but the most severe storms occur more often.

[1]  A. Betts,et al.  Contrasting convective regimes over the Amazon: Implications for cloud electrification , 2002 .

[2]  V. Canuto,et al.  Present-Day Atmospheric Simulations Using GISS ModelE: Comparison to In Situ, Satellite, and Reanalysis Data , 2006 .

[3]  Walter A. Petersen,et al.  Regional Variability in Tropical Convection: Observations from TRMM , 2001 .

[4]  H. Ye,et al.  The Changes in Russian Winter Snow Accumulation during 1936–83 and Its Spatial Patterns , 1998 .

[5]  Mark New,et al.  Surface air temperature and its changes over the past 150 years , 1999 .

[6]  Joanne Simpson,et al.  MODELS OF PRECIPITATING CUMULUS TOWERS , 1969 .

[7]  Charles A. Doswell,et al.  Severe Convective Storms , 2001 .

[8]  Edward J. Zipser,et al.  A Census of Precipitation Features in the Tropics Using TRMM: Radar, Ice Scattering, and Lightning Observations , 2000 .

[9]  Leo J. Donner,et al.  A Cumulus Parameterization Including Mass Fluxes, Convective Vertical Velocities, and Mesoscale Effects: Thermodynamic and Hydrological Aspects in a General Circulation Model , 2001 .

[10]  E. Williams,et al.  Lightning and climate: A review , 2005 .

[11]  D. Boccippio.  Lightning Scaling Relations Revisited , 2002 .

[12]  W. Cotton,et al.  Storm and Cloud Dynamics , 1992 .

[13]  Y. Sud,et al.  Microphysics of Clouds with the Relaxed Arakawa–Schubert Scheme (McRAS). Part I: Design and Evaluation with GATE Phase III Data , 1999 .

[14]  Dennis L. Hartmann.  Tropical Surprises , 2002, Science.

[15]  N. Dotzek.  Book review: Doswell, C. A., 2001: Severe Convective Storms. Meteor. Monogr., 28(50), Amer. Meteor. Soc., Boston, 561 S. , 2004 .

[16]  CAPE Variations in the Current Climate and in a Climate Change , 1998 .

[17]  A. Weaver,et al.  Detecting the effect of climate change on Canadian forest fires , 2004 .

[18]  A. D. Del Genio,et al.  Relationships between lightning and properties of convective cloud clusters , 2007 .

[19]  Raúl E. López,et al.  Lightning Casualties and Damages in the United States from 1959 to 1994 , 2000 .

[20]  D. Allen,et al.  Evaluation of lightning flash rate parameterizations for use in a global chemical transport model , 2002 .

[21]  D. Rind,et al.  Use of microwave brightness temperatures with a general circulation model , 1995 .

[22]  D. Gregory.  Estimation of entrainment rate in simple models of convective clouds , 2001 .

[23]  David P. Yorty,et al.  WHERE ARE THE MOST INTENSE THUNDERSTORMS ON EARTH , 2006 .

[24]  M. Yao,et al.  Cumulus Microphysics and Climate Sensitivity , 2005 .

[25]  Harold E. Brooks,et al.  The spatial distribution of severe thunderstorm and tornado environments from global reanalysis data , 2003 .

[26]  A. Genio,et al.  Factors Limiting Convective Cloud-Top Height at the ARM Nauru Island Climate Research Facility , 2006 .

[27]  E. Williams,et al.  The physical origin of the land–ocean contrast in lightning activity , 2002 .

[28]  David Rind,et al.  The Impact of a 2 × CO2 Climate on Lightning-Caused Fires , 1994 .

[29]  E. Zipser,et al.  The Vertical Profile of Radar Reflectivity of Convective Cells: A Strong Indicator of Storm Intensity and Lightning Probability? , 1994 .

[30]  Itamar M. Lensky,et al.  Satellite-Based Insights into Precipitation Formation Processes in Continental and Maritime Convective Clouds , 1998 .

[31]  D. Rind,et al.  Possible implications of global climate change on global lightning distributions and frequencies , 1994 .

[32]  J. Royer,et al.  Contribution to the climatological study of lightning , 1999 .

[33]  T. Swetnam,et al.  Warming and Earlier Spring Increase Western U.S. Forest Wildfire Activity , 2006, Science.