Impact of Convective Organization on the Response of Tropical Precipitation Extremes to Warming

被引:63
作者
Muller, Caroline [1 ,2 ]
机构
[1] Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA
[2] Ecole Polytech, CNRS, Lab Hydrodynam LadHyX, F-91128 Palaiseau, France
关键词
D O I
10.1175/JCLI-D-12-00655.1
中图分类号
P4 [大气科学(气象学)];
学科分类号
0706 ; 070601 ;
摘要
In this study the response of tropical precipitation extremes to warming in organized convection is examined using a cloud-resolving model. Vertical shear is imposed to organize the convection into squall lines. Earlier studies show that in disorganized convection, the fractional increase of precipitation extremes is similar to that of surface water vapor, which is substantially smaller than the increase in column water vapor. It has been suggested that organized convection could lead to stronger amplifications. Regardless of the strength of the shear, amplifications of precipitation extremes in the cloud-resolving simulations are comparable to those of surface water vapor and are substantially less than increases in column water vapor. The results without shear and with critical shear, for which the squall lines are perpendicular to the shear, are surprisingly similar with a fractional rate of increase of precipitation extremes slightly smaller than that of surface water vapor. Interestingly, the dependence on shear is nonmonotonic, and stronger supercritical shear yields larger rates, close to or slightly larger than surface humidity. A scaling is used to evaluate the thermodynamic and dynamic contributions to precipitation extreme changes. To first order, they are dominated by the thermodynamic component, which has the same magnitude for all shears, close to the change in surface water vapor. The dynamic contribution plays a secondary role and tends to weaken extremes without shear and with critical shear, while it strengthens extremes with supercritical shear. These different dynamic contributions for different shears are due to different responses of convective mass fluxes in individual updrafts to warming.
引用
收藏
页码:5028 / 5043
页数:16
相关论文
共 48 条
[1]   Atmospheric warming and the amplification of precipitation extremes [J].
Allan, Richard P. ;
Soden, Brian J. .
SCIENCE, 2008, 321 (5895) :1481-1484
[2]   Constraints on future changes in climate and the hydrologic cycle [J].
Allen, MR ;
Ingram, WJ .
NATURE, 2002, 419 (6903) :224-+
[3]   THERMODYNAMIC CONSTRAINT ON THE CLOUD LIQUID WATER FEEDBACK IN CLIMATE MODELS [J].
BETTS, AK ;
HARSHVARDHAN .
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 1987, 92 (D7) :8483-8485
[4]   Climate-convection feedbacks: Some further issues - An editorial comment [J].
Betts, AK .
CLIMATIC CHANGE, 1998, 39 (01) :35-38
[5]   An energy-balance analysis of deep convective self-aggregation above uniform SST [J].
Bretherton, CS ;
Blossey, PN ;
Khairoutdinov, M .
JOURNAL OF THE ATMOSPHERIC SCIENCES, 2005, 62 (12) :4273-4292
[6]   Dynamic and thermodynamic changes in mean and extreme precipitation under changed climate [J].
Emori, S ;
Brown, SJ .
GEOPHYSICAL RESEARCH LETTERS, 2005, 32 (17) :1-5
[7]  
FOVELL RG, 1988, J ATMOS SCI, V45, P3846, DOI 10.1175/1520-0469(1988)045<3846:NSOAMS>2.0.CO
[8]  
2
[9]  
GARNER ST, 1992, Q J ROY METEOR SOC, V118, P101, DOI 10.1002/qj.49711850306
[10]   An important constraint on tropical cloud - climate feedback [J].
Hartmann, DL ;
Larson, K .
GEOPHYSICAL RESEARCH LETTERS, 2002, 29 (20)