scholarly journals Projected Changes in Summertime Circulation Patterns Imply Increased Drought Risk for the South‐Central United States

2018 ◽  
Vol 45 (20) ◽  
Author(s):  
Jung‐Hee Ryu ◽  
Katharine Hayhoe ◽  
Song‐Lak Kang
2017 ◽  
Vol 108 (3) ◽  
pp. 739-755 ◽  
Author(s):  
Volodymyr V. Mihunov ◽  
Nina S. N. Lam ◽  
Lei Zou ◽  
Robert V. Rohli ◽  
Nazla Bushra ◽  
...  

2021 ◽  
Vol 2 ◽  
Author(s):  
Estelle Levetin

Climate change is having a significant effect on many allergenic plants resulting in increased pollen production and shifts in plant phenology. Although these effects have been well-studied in some areas of the world, few studies have focused on long-term changes in allergenic pollen in the South Central United States. This study examined airborne pollen, temperature, and precipitation in Tulsa, Oklahoma over 25 to 34 years. Pollen was monitored with a Hirst-type spore trap on the roof of a building at the University of Tulsa and meteorology data were obtained from the National Weather Service. Changes in total pollen intensity were examined along with detailed analyses of the eight most abundant pollen types in the Tulsa atmosphere. In addition to pollen intensity, changes in pollen season start date, end date, peak date and season duration were also analyzed. Results show a trend to increasing temperatures with a significant increase in annual maximum temperature. There was a non-significant trend toward increasing total pollen and a significant increase in tree pollen over time. Several individual taxa showed significant increases in pollen intensity over the study period including spring Cupressaceae and Quercus pollen, while Ambrosia pollen showed a significant decrease. Data from the current study also indicated that the pollen season started earlier for spring pollinating trees and Poaceae. Significant correlations with preseason temperature may explain the earlier pollen season start dates along with a trend toward increasing March temperatures. More research is needed to understand the global impact of climate change on allergenic species, especially from other regions that have not been studied.


1990 ◽  
Vol 14 (2) ◽  
pp. 59-63
Author(s):  
William H. McWilliams

Abstract Commercial harvests were carried out on 36% of the pine-site timberland in six states of the south-central United States during the interval of time between the last two forest inventories of each state. Half of forest industry's pine-site timberland was harvested, compared with 30% for nonindustrial private owners. Fifty-four percent of the heavily cut pine stands were at least 60% stocked with pine following harvest. The overall rate of replacement for pine stands was 78%. South. J. Appl. For. 14(2):59-63.


2019 ◽  
Vol 20 (3) ◽  
pp. 549-562 ◽  
Author(s):  
Jason A. Otkin ◽  
Yafang Zhong ◽  
Eric D. Hunt ◽  
Jeff Basara ◽  
Mark Svoboda ◽  
...  

Abstract This study examines the evolution of soil moisture, evapotranspiration, vegetation, and atmospheric conditions during an unusual flash drought–flash recovery sequence that occurred across the south-central United States during 2015. This event was characterized by a period of rapid drought intensification (flash drought) during late summer that was terminated by heavy rainfall at the end of October that eliminated the extreme drought conditions over a 2-week period (flash recovery). A detailed analysis was performed using time series of environmental variables derived from meteorological, remote sensing, and land surface modeling datasets. Though the analysis revealed a similar progression of cascading effects in each region, characteristics of the flash drought such as its onset time, rate of intensification, and vegetation impacts differed between regions due to variations in the antecedent conditions and the atmospheric anomalies during its growth. Overall, flash drought signals initially appeared in the near-surface soil moisture, followed closely by reductions in evapotranspiration. Total column soil moisture deficits took longer to develop, especially in the western part of the region where heavy rainfall during the spring and early summer led to large moisture surpluses. Large differences were noted in how land surface models in the North American Land Data Assimilation System depicted soil moisture evolution during the flash drought; however, the models were more similar in their assessment of conditions during the flash recovery period. This study illustrates the need to use multiple datasets to track the evolution and impacts of rapidly evolving flash drought and flash recovery events.


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