CHANGES IN REGIONAL PRECIPITATION DISTRIBUTION IN RESPONSE TO GLOBAL WARMING

Ambient Factors Controlling the Wintertime Precipitation Distribution across Mountain Ranges in the Interior Western United States. Part II: Changes in Orographic Precipitation Distribution in a Pseudo–Global Warming Simulation

Journal of Applied Meteorology and Climatology ◽

10.1175/jamc-d-18-0173.1 ◽

2019 ◽

Vol 58 (4) ◽

pp. 695-715 ◽

Cited By ~ 3

Author(s):

Xiaoqin Jing ◽

Bart Geerts ◽

Yonggang Wang ◽

Changhai Liu

Keyword(s):

United States ◽

Global Warming ◽

Western United States ◽

Cmip5 Models ◽

Cloud Base ◽

Orographic Precipitation ◽

Precipitation Distribution ◽

Mountain Ranges ◽

Ensemble Mean ◽

Precipitation Increase

AbstractTwo high-resolution (4 km) regional climate simulations over a 10-yr period are conducted to study the changes in wintertime precipitation distribution across mountain ranges in the interior western United States (IWUS) in a warming climate. One simulation represents the current climate, and another represents an ~2050 climate using a pseudo–global warming approach. The climate perturbations are derived from the ensemble mean of 15 global climate models from phase 5 of the Coupled Model Intercomparison Project (CMIP5). These simulations provide an estimate of average changes in wintertime orographic precipitation enhancement and finescale distribution across mountain ranges. The variability in these changes among CMIP5 models is quantified using statistical downscaling relations between orographic precipitation distribution and upstream conditions, developed in Part I. The CMIP5 guidance indicates a robust warming signal (~2 K) over the IWUS by ~2050 but minor changes in relative humidity and cloud-base height. The IWUS simulations reveal a widespread increase in precipitation on account of higher precipitation rates during winter storms in this warmer climate. This precipitation increase is most significant over the mountains rather than on the surrounding plains. The increase in precipitation rate is largely due to an increase in low-level cross-mountain moisture transport. The application of the statistical relations indicates that individual CMIP5 models disagree about the magnitude and distribution of orographic precipitation change in the IWUS, although most agree with the ensemble-mean-predicted orographic precipitation increase.

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Linking regional changes in the intensity distribution of daily tropical precipitation to changes in large-scale circulation and convective inhibition

10.5194/egusphere-egu2020-7761 ◽

2020 ◽

Author(s):

Robin Chadwick ◽

Angeline Pendergrass ◽

Segolene Berthou ◽

Lincoln Alves ◽

Aurel Moise

Keyword(s):

Global Warming ◽

Intensity Distribution ◽

Large Scale ◽

Tropical Region ◽

Large Scale Circulation ◽

Precipitation Distribution ◽

Tropical Precipitation ◽

Distribution Change ◽

Convective Inhibition ◽

Static Energy

<p>Global warming is expected to change the intensity distribution of daily tropical precipitation, with an increased frequency of heavy precipitation and reduced frequency of light precipitation. In general, this is likely to increase the risk of flooding, while also increasing the risk of long dry periods. However, on regional scales circulation change plays a major role in modulating this precipitation distribution change in climate model projections, so related climate change impacts will also be regionally dependent.</p><p>We propose a simple physical framework based on the dry static energy budget which explains regional daily precipitation distribution change in terms of changes in two physical drivers: large-scale circulation and time-mean convective inhibition (CIN). In this framework, increased CIN under global warming tends to reduce the frequency of convection, leading to a greater &#8216;recharge&#8217; of instability between convective events, and consequently greater &#8216;discharge&#8217; of latent heating (precipitation) during each event. Large-scale circulation regulates the speed of this recharge of instability via dry static energy flux convergence or divergence, and its change under warming is very regionally dependent. Changes in regional time-mean tropical precipitation are closely related to changes in large-scale circulation, so this framework also provides a physical link between changes in time-mean precipitation and changes in the daily intensity distribution of precipitation in each tropical region.&#160;</p>

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Modelling ecosystem adaptation and dangerous rates of global warming

Emerging Topics in Life Sciences ◽

10.1042/etls20180113 ◽

2019 ◽

Vol 3 (2) ◽

pp. 221-231 ◽

Cited By ~ 4

Author(s):

Rebecca Millington ◽

Peter M. Cox ◽

Jonathan R. Moore ◽

Gabriel Yvon-Durocher

Keyword(s):

Climate Change ◽

Global Warming ◽

Diffusion Rate ◽

Individual Species ◽

Genetic Evolution ◽

Rates Of Change ◽

Rapid Climate Change ◽

Warming Climate ◽

Intraspecies Competition ◽

High Trait

Abstract We are in a period of relatively rapid climate change. This poses challenges for individual species and threatens the ecosystem services that humanity relies upon. Temperature is a key stressor. In a warming climate, individual organisms may be able to shift their thermal optima through phenotypic plasticity. However, such plasticity is unlikely to be sufficient over the coming centuries. Resilience to warming will also depend on how fast the distribution of traits that define a species can adapt through other methods, in particular through redistribution of the abundance of variants within the population and through genetic evolution. In this paper, we use a simple theoretical ‘trait diffusion’ model to explore how the resilience of a given species to climate change depends on the initial trait diversity (biodiversity), the trait diffusion rate (mutation rate), and the lifetime of the organism. We estimate theoretical dangerous rates of continuous global warming that would exceed the ability of a species to adapt through trait diffusion, and therefore lead to a collapse in the overall productivity of the species. As the rate of adaptation through intraspecies competition and genetic evolution decreases with species lifetime, we find critical rates of change that also depend fundamentally on lifetime. Dangerous rates of warming vary from 1°C per lifetime (at low trait diffusion rate) to 8°C per lifetime (at high trait diffusion rate). We conclude that rapid climate change is liable to favour short-lived organisms (e.g. microbes) rather than longer-lived organisms (e.g. trees).

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