scholarly journals Projected Changes to Spring and Summer Precipitation in the Midwestern United States

2021 ◽  
Vol 3 ◽  
Author(s):  
Kevin A. Grady ◽  
Liang Chen ◽  
Trent W. Ford
Keyword(s):  
United States ◽  
Summer Precipitation ◽  
Fold Increase ◽  
The United States ◽  
Spring Precipitation ◽  
Projected Change ◽  
High Emission ◽  
Projected Changes ◽  
Precipitation Changes ◽  
Model Agreement

Spring and summer precipitation are both important factors for agricultural productivity in the Midwest region of the United States. Adequate summer precipitation, particularly in the reproductive and grain fill stages in July and August, is critical to corn and soybean success. Meanwhile, excessive spring precipitation can cause significant planting delays and introduces challenges with weed and pest management, and soil erosion and compaction. However, uncertainty especially in future summer precipitation changes, translates to uncertainties in how the joint distributions of spring and summer precipitation are expected to change by mid- and late-century across the Midwest. This study examines historical and projected changes in the characteristics of spring and summer precipitation in the Midwest using 12 dynamically downscaled simulations under the high-emission representative concentration pathway (RCP 8.5) from the NA-CORDEX project. Historical increases in spring precipitation and precipitation intensity are projected to continue into the mid- and late-century across the region, with strong model agreement. By comparison, projected changes in Midwest summer precipitation are more modest than for spring and have much less model agreement. Despite a projected three- to four-fold increase in the frequency of wet springs by late-century, relative to the model ensemble historical average, the lack of substantial and robust projected change in summer precipitation results in only a small increase in the risk of dry summers following wet springs in the Midwest by mid- and late-century.

Modeling Tamarisk (Tamarix spp.) Habitat and Climate Change Effects in the Northwestern United States

2009 ◽  
Vol 2 (3) ◽  
pp. 200-215 ◽  
Author(s):  
Becky K. Kerns ◽  
Bridgett J. Naylor ◽  
Michelle Buonopane ◽  
Catherine G. Parks ◽  
Brendan Rogers
Keyword(s):  
Climate Change ◽  
United States ◽  
Habitat Suitability ◽  
Fold Increase ◽  
The United States ◽  
Future Climate Change ◽  
Distribution Data ◽  
Climate Data ◽  
Considerable Uncertainty ◽  
Projected Changes

AbstractTamarisk species are shrubs or small trees considered by some to be among the most aggressively invasive and potentially detrimental exotic plants in the United States. Although extensively studied in the southern and interior west, northwestern (Oregon, Washington, and Idaho) distribution and habitat information for tamarisk is either limited or lacking. We obtained distribution data for the northwest, developed a habitat suitability map, and projected changes in habitat due to climate change in a smaller case study area using downscaled climate data. Results show extensive populations of tamarisk east of the Cascade Mountains. Despite the perceived novelty of tamarisk in the region, naturalized populations were present by the 1920s. Major population centers are limited to the warmest and driest environments in the central Snake River Plain, Columbia Plateau, and Northern Basin and Range. Habitat suitability model results indicate that 21% of the region supports suitable tamarisk habitat. Less than 1% of these areas are occupied by tamarisk; the remainder is highly vulnerable to invasion. Although considerable uncertainty exists regarding future climate change, we project a 2- to 10-fold increase in highly suitable tamarisk habitat by the end of the century. Our habitat suitability maps can be used in “what if” exercises as part of planning, detection, restoration, management, and eradication purposes.

scholarly journals Probabilistic Projections of Anthropogenic Climate Change Impacts on Precipitation for the Mid-Atlantic Region of the United States*

2012 ◽  
Vol 25 (15) ◽  
pp. 5273-5291 ◽  
Author(s):  
Liang Ning ◽  
Michael E. Mann ◽  
Robert Crane ◽  
Thorsten Wagener ◽  
Raymond G. Najjar ◽  
...  
Keyword(s):  
United States ◽  
General Circulation ◽  
Circulation Model ◽  
Summer Precipitation ◽  
Climate Change Impacts ◽  
The United States ◽  
Winter Precipitation ◽  
Specific Humidity ◽  
Atlantic Region ◽  
Projected Changes

Abstract This study uses an empirical downscaling method based on self-organizing maps (SOMs) to produce high-resolution, downscaled precipitation projections over the state of Pennsylvania in the mid-Atlantic region of the United States for the future period 2046–65. To examine the sensitivity of precipitation change to the water vapor increase brought by global warming, the authors test the following two approaches to downscaling: one uses the specific humidity in the downscaling algorithm and the other does not. Application of the downscaling procedure to the general circulation model (GCM) projections reveals changes in the relative occupancy, but not the fundamental nature, of the simulated synoptic circulation states. Both downscaling approaches predict increases in annual and winter precipitation, consistent in sign with the “raw” output from the GCMs but considerably smaller in magnitude. For summer precipitation, larger discrepancies are seen between raw and downscaled GCM projections, with a substantial dependence on the downscaling version used (downscaled precipitation changes employing specific humidity are smaller than those without it). Application of downscaling generally reduces the inter-GCM uncertainties, suggesting that some of the spread among models in the raw projected precipitation may result from differences in precipitation parameterization schemes rather than fundamentally different climate responses. Projected changes in the North Atlantic Oscillation (NAO) are found to be significantly related to changes in winter precipitation in the downscaled results, but not for the raw GCM results, suggesting that the downscaling more effectively captures the influence of climate dynamics on projected changes in winter precipitation.

scholarly journals Contribution of Cutoff Lows to Precipitation across the United States

2016 ◽  
Vol 55 (4) ◽  
pp. 893-899 ◽  
Author(s):  
John T. Abatzoglou
Keyword(s):  
United States ◽  
Great Plains ◽  
Summer Precipitation ◽  
The United States ◽  
Precipitation Variability ◽  
Western United States ◽  
Spring Precipitation ◽  
Mountain Ranges ◽  
Extreme Precipitation Events ◽  
Slow Moving

AbstractA chronology of cutoff lows (COL) from 1979 to 2014 alongside daily precipitation observations across the conterminous United States was used to examine the contribution of COL to seasonal precipitation, extreme-precipitation events, and interannual precipitation variability. COL accounted for between 2% and 32% of annual precipitation at stations across the United States, with distinct geographic and seasonal variability. The largest fractional contribution of COL to precipitation totals and precipitation extremes was found across the Great Plains and the interior western United States, particularly during the transition seasons of spring and autumn. Widespread significant correlations between seasonal COL precipitation and total precipitation on interannual time scales were found across parts of the United States, most notably to explain spring precipitation variability in the interior western United States and Great Plains and summer precipitation variability in the northwestern United States. In addition to regional differences, a distinct gradient in the contributions of COL to precipitation was found in the lee of large mountain ranges in the western United States. Differences in orographic precipitation enhancement associated with slow-moving COL resulted in relatively more precipitation at lower elevations and, in particular, east of north–south-oriented mountain ranges that experience a strong rain shadow with progressive disturbances.

Racial and Political Dynamics of an Approaching “Majority-Minority” United States

2018 ◽  
Vol 677 (1) ◽  
pp. 204-214 ◽  
Author(s):  
Maureen A. Craig ◽  
Julian M. Rucker ◽  
Jennifer A. Richeson
Keyword(s):  
United States ◽  
The United States ◽  
Future Research ◽  
White Americans ◽  
Psychological Mechanisms ◽  
Political Outcomes ◽  
Essential Questions ◽  
Social Scientific ◽  
Demographic Shifts ◽  
Projected Changes

Do demographic shifts in the racial composition of the United States promote positive changes in the nation’s racial dynamics? Change in response to the nation’s growing diversity is likely, but its direction and scope are less clear. This review integrates emerging social-scientific research that examines how Americans are responding to the projected changes in the racial/ethnic demographics of the United States. Specifically, we review recent empirical research that examines how exposure to information that the United States is becoming a “majority-minority” nation affects racial attitudes and several political outcomes (e.g., ideology, policy preferences), and the psychological mechanisms that give rise to those attitudes. We focus primarily on the reactions of members of the current dominant racial group (i.e., white Americans). We then consider important implications of these findings and propose essential questions for future research.

scholarly journals Heat Vulnerability and Heat Island Mitigation in the United States

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 558 ◽  
Author(s):  
Jungmin Lim ◽  
Mark Skidmore
Keyword(s):  
United States ◽  
Local Governments ◽  
Heat Waves ◽  
Fold Increase ◽  
The United States ◽  
Extreme Heat ◽  
Mitigation Measures ◽  
Heat Island ◽  
Weather Extremes ◽  
Heat Vulnerability

Heat waves are the deadliest type of natural hazard among all weather extremes in the United States. Given the observed and anticipated increase in heat risks associated with ongoing climate change, this study examines community vulnerability to extreme heat and the degree to which heat island mitigation (HIM) actions by state/local governments reduce heat-induced fatalities. The analysis uses all heat events that occurred over the 1996–2011 period for all United States counties to model heat vulnerability. Results show that: (1) Higher income reduces extreme heat vulnerability, while poverty intensifies it; (2) living in mobile homes or rental homes heightens susceptibility to extreme heat; (3) increased heat vulnerability due to the growth of the elderly population is predicted to result in a two-fold increase in heat-related fatalities by 2030; and (4) community heat island mitigation measures reduce heat intensities and thus heat-related fatalities. Findings also show that an additional locally implemented measure reduces the annual death rate by 15%. A falsification test rules out the possibility of spurious inference on the life-saving role of heat island mitigation measures. Overall, these findings inform efforts to protect the most vulnerable population subgroups and guide future policies to counteract the growing risk of deadly heat waves.

scholarly journals Holocene Hydroclimate in the Southeastern United States During Abrupt Climate Events: Evidence From New Speleothem Isotopic Records From Alabama

2021 ◽  
Author(s):  
Martin Medina-Elizalde ◽  
Stefan Perritano ◽  
Matthew DeCesare ◽  
Josué Polanco-Martinez ◽  
Gabriela Serrato-Marks ◽  
...  
Keyword(s):  
United States ◽  
Model Simulation ◽  
Southeastern United States ◽  
Precipitation Amount ◽  
Summer Precipitation ◽  
Winter Precipitation ◽  
Meridional Overturning Circulation ◽  
Ice Age ◽  
Annual Rainfall ◽  
Spring Precipitation

Abstract We present new high-resolution absolute-dated stalagmite δ18O and δ13C records from the southeastern United States (SE US) spanning the last 12 thousand years (ka). A local relationship between annual rainfall amount and its amount-weighed δ18O composition exists on interannual timescales, driven mostly by an amount effect during summer and spring seasons, and by an isotopically depleted composition of fall and winter precipitation. Based on a novel interpretation of modern rainfall isotopic data, stalagmite δ18O variability is interpreted to reflect the relative contribution of summer and spring precipitation combined relative to combined fall and winter precipitation. Precipitation amount in the SE US increases during the Younger Dryas, the 8.2 ka and Little Ice Age abrupt cooling events. High precipitation during these events reflects enhancement of spring and summer precipitation while the contribution of fall and winter rainfall remained unchanged or decreased slightly. Results from this study support model simulation results that suggest increased precipitation in the SE US during Atlantic Meridional Overturning Circulation (AMOC) slowdown/shutdown (LeGrande et al., 2006; Renssen et al., 2002; Vellinga and Wood, 2002). In association with Northern Hemisphere mid-latitude cooling from the Early to mid-Holocene, annual precipitation in the SE US decreases, a pattern distinctive from that observed during abrupt cooling events related to AMOC shifts. Long-term hydroclimate change in the SE US is likely sensitive to summer insolation reduction as inferred for other tropical and subtropical regions. This study has implications for our understanding of the sensitivity of subtropical hydroclimate to factors both internal and external to the climate system in a warmer climate.

scholarly journals LB11. Rapid Rise in Decreased Susceptibility to Azithromycin among Shigella Isolates in the United States: A Look at National Surveillance Data, 2011–2017

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S763-S763 ◽  
Author(s):  
Cindy Friedman ◽  
Ian Plumb ◽  
Jared Reynolds ◽  
Jessica Chen ◽  
Kaitlin Tagg ◽  
...  
Keyword(s):  
United States ◽  
Resistance Mechanism ◽  
Fold Increase ◽  
The United States ◽  
Adult Males ◽  
Rapid Rise ◽  
Transmitted Infection ◽  
Sexually Transmitted ◽  
Increased Risk ◽  
Sex With Men

Abstract Background Shigella spp. cause ~500,000 illnesses in the United States annually. Antibiotics are recommended for immunocompromised patients and shorten the duration of illness, thus limiting spread. First-line treatments include ciprofloxacin (CIP) and azithromycin (AZM). CIP resistance is a growing problem in the United States; decreased susceptibility to AZM (DSA) has been reported globally, particularly among men who have sex with men (MSM). We reviewed National Antimicrobial Resistance Monitoring System (NARMS) data to determine DSA trends among Shigella isolates in the United States. Methods Health departments nationwide forward every 20th Shigella isolate to CDC NARMS for antimicrobial susceptibility testing using broth microdilution. We defined CIP resistance using CLSI clinical breakpoints and DSA using epidemiological cutoff values where available. We performed whole genome sequencing on isolates from 2016 and screened the sequences for resistance determinants using ResFinder 3.0. Results To date, we have tested 3,044 Shigella isolates collected during 2011–2017. Overall, 264 isolates (9%) had DSA, increasing from 3% in 2011 to 23% in 2017; 41 (16%) were also CIP resistant. The odds of DSA increased by 1.5 (95% confidence interval [CI] 1.4–1.6) annually. DSA was more common among adult males (OR 21.2, CI 14.9–30.3), in isolates from the West census region (OR 2.4, CI 1.8–3.2), and in S. flexneri (OR 8.2, CI 6.3–10.7). Of 543 sequenced isolates, 52 (10%) had DSA; of these, 31 (60%) contained both mph(A) and erm(B) genes, 17 (33%) contained mph(A) only, and 4 (8%) had no identified macrolide-resistance mechanism. Conclusions In 2017, nearly 1 in 4 Shigella isolates tested had DSA, a 7-fold increase since 2011. This rapid rise in DSA parallels that seen in other countries, where resistance to other clinically relevant drugs is high and macrolides are no longer useful as empiric treatment. The increased risk of DSA in adult males is consistent with previous reports of DSA Shigella in MSM. The resistance genes observed are typically plasmid-mediated and can be transferred to other bacteria. Public health strategies to mitigate the spread of resistant Shigella should include antibiotic stewardship and novel approaches for sexually transmitted infection prevention in MSM. Disclosures All authors: No reported disclosures.

Sign in / Sign up

Export Citation Format

Share Document