Physical Sciences and Mathematics | Open Access Articles

Deadly Heat Waves Projected In The Densely Populated Agricultural Regions Of South Asia, Eun-Soon Im, Jeremy S. Pal, Elfatih A. B. Eltahir

Civil and Environmental Engineering Faculty Works

The risk associated with any climate change impact reflects intensity of natural hazard and level of human vulnerability. Previous work has shown that a wet-bulb temperature of 35°C can be considered an upper limit on human survivability. On the basis of an ensemble of high-resolution climate change simulations, we project that extremes of wet-bulb temperature in South Asia are likely to approach and, in a few locations, exceed this critical threshold by the late 21st century under the business-as-usual scenario of future greenhouse gas emissions. The most intense hazard from extreme future heat waves is concentrated around densely populated agricultural …

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Metals And Bacteria Partitioning To Various Size Particles In Ballona Creek Storm Water Runoff, John Dorsey, Jeffrey S. Brown, Eric D. Stein, Drew Ackerman, Jessica Lyon, Patrick M. Carter

Civil and Environmental Engineering Faculty Works

Many storm water best management practice (BMP) devices function primarily by capturing particulate matter to take advantage of the well-documented association between storm water particles and pollutants. The hydrodynamic separation or settling methods used by most BMP devices are most effective at capturing medium to large particles; however, these may not be the most predominant particles associated with urban runoff. The present study examined particle size distribution in storm water runoff from an urban watershed in southern California and investigated the pollutant-particle associations of metals (Cu, Pb, Ni, and Zn) and bacteria (enterococci and Escherichia coli). During small storm events …

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Consistency Of Projected Drought Over The Sahel With Changes In The Monsoon Circulation And Extremes In A Regional Climate Model Projections, M. B. Sylla, A. T. Gaye, G. S. Jenkins, Jeremy S. Pal, F. Giorgi

Civil and Environmental Engineering Faculty Works

As a step toward an increased understanding of climate change over West Africa, in this paper we analyze the relationship between rainfall changes and monsoon dynamics in high-resolution regional climate model experiments performed using the Regional Climate Model (RegCM3). Multidecadal simulations are carried out for present-day and future climate conditions under increased greenhouse gas forcing driven by the global climate model European Center/Hamburg 5 (ECHAM5). Compared to the present day, the future scenario simulation produces drier conditions over the Sahel and wetter conditions over orographic areas. The Sahel drying is accompanied by a weaker monsoon flow, a southward migration and …

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Suppression Of South Asian Summer Monsoon Precipitation In The 21st Century, Moetasim Ashfaq, Ying Shi, Wen-Wen Tung, Robert J. Trapp, Xueijie Gao, Jeremy S. Pal, Noah S. Diffenbaugh

Civil and Environmental Engineering Faculty Works

We used a high-resolution nested climate modeling system to investigate the response of South Asian summer monsoon dynamics to anthropogenic increases in greenhouse gas concentrations. The simulated dynamical features of the summer monsoon compared well with reanalysis data and observations. Further, we found that enhanced greenhouse forcing resulted in overall suppression of summer precipitation, a delay in monsoon onset, and an increase in the occurrence of monsoon break periods. Weakening of the large-scale monsoon flow and suppression of the dominant intraseasonal oscillatory modes were instrumental in the overall weakening of the South Asian summer monsoon. Such changes in monsoon dynamics …

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Future Changes In Snowmelt-Driven Runoff Timing Over The Western Us, Sara A. Rauscher, Jeremy S. Pal, Noah S. Diffenbaugh, Michael M. Benedetti

Civil and Environmental Engineering Faculty Works

We use a high-resolution nested climate model to investigate future changes in snowmelt-driven runoff (SDR) over the western US. Comparison of modeled and observed daily runoff data reveals that the regional model captures the present-day timing and trends of SDR. Results from an A2 scenario simulation indicate that increases in seasonal temperature of approximately 3° to 5°C resulting from increasing greenhouse gas concentrations could cause SDR to occur as much as two months earlier than present. These large changes result from an amplified snow-albedo feedback driven by the topographic complexity of the region, which is more accurately resolved in a …

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Changes In Severe Thunderstorm Environment Frequency During The 21st Century Caused By Anthropogenically Enhanced Global Radiative Forcing, Robert J. Trapp, Noah S. Diffenbaugh, Harold E. Brooks, Michael E. Baldwin, Eric D. Robinson, Jeremy S. Pal

Civil and Environmental Engineering Faculty Works

Severe thunderstorms comprise an extreme class of deep convective clouds and produce high-impact weather such as destructive surface winds, hail, and tornadoes. This study addresses the question of how severe thunderstorm frequency in the United States might change because of enhanced global radiative forcing associated with elevated greenhouse gas concentrations. We use global climate models and a high-resolution regional climate model to examine the larger-scale (or “environmental”) meteorological conditions that foster severe thunderstorm formation. Across this model suite, we find a net increase during the late 21st century in the number of days in which these severe thunderstorm environmental conditions …

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Regional Climate Modeling For The Developing World: The Ictp Regcm3 And Regcnet, Jeremy S. Pal, Filippo Giorgi, Xunqiang Bi, Nellie Elguindi, Fabien Solmon, Xuejie Gao, Sara A. Rauscher, Raquel Francisco, Ashraf Zakey, Jonathan Winter, Moetasim Ashfaq, Faisal S. Syed, Jason L. Bell, Noah S. Diffenbaugh, Jagadish Karmacharya, Abourahamane Konaré, Daniel Martinez, Rosmeri P. Da Rocha, Lisa C. Sloan, Allison L. Steiner

Civil and Environmental Engineering Faculty Works

Regional climate models are important research tools available to scientists around the world, including in economically developing nations (EDNs). The Earth Systems Physics (ESP) group of the Abdus Salam International Centre for Theoretical Physics (ICTP) maintains and distributes a state-of-the-science regional climate model called the ICTP Regional Climate Model version 3 (RegCM3), which is currently being used by a large research community for a diverse range of climate-related studies. The RegCM3 is the central, but not only, tool of the ICTP-maintained Regional Climate Research Network (RegCNET) aimed at creating south–south and north–south scientific interactions on the topic of climate and …

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Connection Between Spring Conditions And Peak Summer Monsoon Rainfall In South America: Role Of Soil Moisture, Surface Temperature, And Topography In Eastern Brazil, Alice M. Grimm, Jeremy S. Pal, Filippo Giorgi

Civil and Environmental Engineering Faculty Works

A link between peak summer monsoon rainfall in central-east Brazil, composing part of the South American monsoon core region, and antecedent conditions in spring is disclosed. Rainfall in this region during part of spring holds a significant inverse correlation with rainfall in peak summer, especially during ENSO years. A surface–atmosphere feedback hypothesis is proposed to explain this relationship: low spring precipitation leads to low spring soil moisture and high late spring surface temperature; this induces a topographically enhanced low-level anomalous convergence and cyclonic circulation over southeast Brazil that enhances the moisture flux from northern and central South America into central-east …

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Storm Effects On Regional Beach Water Quality Along The Southern California Shoreline, Rachel T. Nobel, Stephen B. Weisberg, Molly K. Leecaster, Charles D. Mcgee, John Dorsey, Patricia Vainik, Victoria Orozco-Borbón

Civil and Environmental Engineering Faculty Works

Two regional studies conducted during dry weather demonstrated that the Southern California Bight (SCB) shoreline has good water quality, except near areas that drain land-based runoff. Here, we repeat those regional studies 36 h after a rainstorm to assess the influence of runoff under high flow conditions. Two hundred and fifty-four shoreline sites between Santa Barbara, California and Ensenada, Mexico were sampled using a stratified-random sampling design with four strata: sandy beaches, rocky shoreline, shoreline adjacent to urban runoff outlets that flow intermittently, and shoreline adjacent to outlets that flow year-round. Each site was sampled for total coliforms, fecal coliforms …

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Full-Text Articles in Physical Sciences and Mathematics

Deadly Heat Waves Projected In The Densely Populated Agricultural Regions Of South Asia, Eun-Soon Im, Jeremy S. Pal, Elfatih A. B. Eltahir

Civil and Environmental Engineering Faculty Works

Metals And Bacteria Partitioning To Various Size Particles In Ballona Creek Storm Water Runoff, John Dorsey, Jeffrey S. Brown, Eric D. Stein, Drew Ackerman, Jessica Lyon, Patrick M. Carter

Civil and Environmental Engineering Faculty Works

Consistency Of Projected Drought Over The Sahel With Changes In The Monsoon Circulation And Extremes In A Regional Climate Model Projections, M. B. Sylla, A. T. Gaye, G. S. Jenkins, Jeremy S. Pal, F. Giorgi

Civil and Environmental Engineering Faculty Works

Suppression Of South Asian Summer Monsoon Precipitation In The 21st Century, Moetasim Ashfaq, Ying Shi, Wen-Wen Tung, Robert J. Trapp, Xueijie Gao, Jeremy S. Pal, Noah S. Diffenbaugh

Civil and Environmental Engineering Faculty Works

Future Changes In Snowmelt-Driven Runoff Timing Over The Western Us, Sara A. Rauscher, Jeremy S. Pal, Noah S. Diffenbaugh, Michael M. Benedetti

Civil and Environmental Engineering Faculty Works

Changes In Severe Thunderstorm Environment Frequency During The 21st Century Caused By Anthropogenically Enhanced Global Radiative Forcing, Robert J. Trapp, Noah S. Diffenbaugh, Harold E. Brooks, Michael E. Baldwin, Eric D. Robinson, Jeremy S. Pal

Civil and Environmental Engineering Faculty Works

Civil and Environmental Engineering Faculty Works

Connection Between Spring Conditions And Peak Summer Monsoon Rainfall In South America: Role Of Soil Moisture, Surface Temperature, And Topography In Eastern Brazil, Alice M. Grimm, Jeremy S. Pal, Filippo Giorgi

Civil and Environmental Engineering Faculty Works

Storm Effects On Regional Beach Water Quality Along The Southern California Shoreline, Rachel T. Nobel, Stephen B. Weisberg, Molly K. Leecaster, Charles D. Mcgee, John Dorsey, Patricia Vainik, Victoria Orozco-Borbón

Civil and Environmental Engineering Faculty Works