scholarly journals Synoptic-Scale Controls of Summer Precipitation in the Southeastern United States

2006 ◽  
Vol 19 (4) ◽  
pp. 613-621 ◽  
Author(s):  
Jeremy E. Diem
Keyword(s):  
United States ◽  
Southeastern United States ◽  
Summer Precipitation ◽  
Future Research ◽  
Strong Impact ◽  
Synoptic Scale ◽  
Precipitation Characteristics ◽  
Daily Precipitation Data ◽  
Upper Level ◽  
June July

Abstract Past climatological research has not quantitatively defined the synoptic-scale circulation deviations responsible for anomalous summer-season precipitation totals in the southeastern United States. Therefore, the objectives of this research were to determine the synoptic-scale controls of wet and dry multiday periods during the summer within a portion of the southeastern United States as well as to assess the linkages between synoptic-scale circulation and multidecadal variations in precipitation characteristics for the study domain. Daily precipitation data from 30 stations for June, July, and August from 1953 to 2002 were converted into 13-day totals. Using standardized principal components analysis (PCA), the study domain was divided into three precipitation regions (i.e., South, Northwest, and Northeast). Wet and dry periods for each region were composed of the top 56 and bottom 56 thirteen-day periods. Composite circulation maps for 500 and 850 mb revealed the following: wet periods were generally associated with an upper-level trough over the interior southeastern United States coincident with strong lower-tropospheric flow into the Southeast from the Gulf of Mexico, and dry periods were characterized by ridges or anticyclones over the midwestern and southeastern United States coupled with weak lower-tropospheric flow. Many of the wet periods had surface fronts. Over the 50-yr period, increased precipitation was significantly correlated with increased occurrences of midtropospheric troughs over the study domain. Future research can benefit from the main finding of a strong impact of synoptic-scale circulation features on summer precipitation in the southeastern United States.

scholarly journals Early indications of drought impacts on forests in the southeastern United States

2015 ◽  
Vol 91 (04) ◽  
pp. 376-383 ◽  
Author(s):  
Michael K. Crosby ◽  
Zhaofei Fan ◽  
Martin A. Spetich ◽  
Theodor D. Leininger ◽  
Xingang Fan
Keyword(s):  
United States ◽  
Forest Type ◽  
Southeastern United States ◽  
Forest Health ◽  
Classification And Regression Tree ◽  
Future Research ◽  
Red Oak ◽  
White Oak ◽  
Cart Analysis ◽  
Crown Dieback

In the southeastern United States, drought can pose a significant threat to forests by reducing the amount of available water, thereby stressing trees. Destructive changes in crown conditions provide the first visible indication of a problem in a forested area, making it a useful indicator for problems within an ecosystem. Forest Health and Monitoring (FHM) and Palmer's Drought Severity Index (PDSI) data from 11 states in the southeastern United States were obtained in an effort to determine the role that drought, forest type, and ecoregion have in indicating differences in crown dieback. Analyses were conducted by species groups using classification and regression tree (CART) analysis. The greatest amount of total relative crown dieback occurred in red oak (18%), followed by other hardwoods (14%), and white oak (11%). Relative crown dieback varied by forest type and ecoregion with a relationship to drought in both red oak and white oak. This information will be useful for focusing future research and modeling efforts to predict forest health conditions affected by changing climate variables.

scholarly journals Precipitation Variations under a Changing Climate from 1961–2015 in the Source Region of the Indus River

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1366
Author(s):  
Muhammad Rizwan ◽  
Xin Li ◽  
Kashif Jamal ◽  
Yingying Chen ◽  
Junaid Nawaz Chauhdary ◽  
...  
Keyword(s):  
Daily Precipitation ◽  
Source Region ◽  
Summer Precipitation ◽  
Heavy Precipitation ◽  
Winter Precipitation ◽  
Indus Basin ◽  
Indus River ◽  
Precipitation Characteristics ◽  
Daily Precipitation Data ◽  
Increasing Trends

The source region of the Indus River (SRIR), which is located in the Hindukush, Karakoram and Himalayan (HKH) mountainous range and on the Third Pole (TP), is very sensitive to climate change, especially precipitation changes, because of its multifarious orography and fragile ecosystem. Climate changes in the SRIR also have important impacts on social and economic development, as well as on the ecosystems of the downstream irrigation areas in Pakistan. This paper investigates the changes in precipitation characteristics by dividing the daily precipitation rate into different classes, such as light (0–10 mm), moderate (10.1–25 mm) and heavy precipitation (>25 mm). Daily precipitation data from gauging and non-gauging stations from 1961–2015 are used. The results of the analysis of the annual precipitation and rainy day trends show significant (p < 0.05) increases and decreases, respectively, while light and heavy precipitation show significant decreasing and increasing trends, respectively. The analysis of the precipitation characteristics shows that light precipitation has the highest number of rainy days compared to moderate or heavy precipitation. The analysis of the seasonal precipitation trends shows that only 18 stations have significant increasing trends in winter precipitation, while 27 stations have significant increasing trends in summer precipitation. Both short and long droughts exhibit increasing trends, which indicates that the Indus Basin will suffer from water shortages for agriculture. The results of this study could help policymakers cope with floods and droughts and sustain eco-environmental resources in the study area.

scholarly journals Synoptic-Scale Flow and Valley Cold Pool Evolution in the Western United States

2009 ◽  
Vol 24 (6) ◽  
pp. 1625-1643 ◽  
Author(s):  
Heather Dawn Reeves ◽  
David J. Stensrud
Keyword(s):  
United States ◽  
Large Scale ◽  
Numerical Models ◽  
Western United States ◽  
Cold Pool ◽  
Synoptic Scale ◽  
Temperature Changes ◽  
Cold Pools ◽  
Upper Level ◽  
Forecast Problem

Abstract Valley cold pools (VCPs), which are trapped, cold layers of air at the bottoms of basins or valleys, pose a significant problem for forecasters because they can lead to several forms of difficult-to-forecast and hazardous weather such as fog, freezing rain, or poor air quality. Numerical models have historically failed to routinely provide accurate guidance on the formation and demise of VCPs, making the forecast problem more challenging. In some case studies of persistent wintertime VCPs, there is a connection between the movement of upper-level waves and the timing of VCP formation and decay. Herein, a 3-yr climatology of persistent wintertime VCPs for five valleys and basins in the western United States is performed to see how often VCP formation and decay coincides with synoptic-scale (∼200–2000 km) wave motions. Valley cold pools are found to form most frequently as an upper-level ridge approaches the western United States and in response to strong midlevel warming. The VCPs usually last as long as the ridge is over the area and usually only end when a trough, and its associated midlevel cooling, move over the western United States. In fact, VCP strength appears to be almost entirely dictated by midlevel temperature changes, which suggests large-scale forcing is dominant for this type of VCP most of the time.

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 The Synoptic Regulation of Dryline Intensity

2007 ◽  
Vol 135 (5) ◽  
pp. 1699-1709 ◽  
Author(s):  
David M. Schultz ◽  
Christopher C. Weiss ◽  
Paul M. Hoffman
Keyword(s):  
United States ◽  
Boundary Layer ◽  
New Mexico ◽  
Short Wave ◽  
Synoptic Scale ◽  
West Texas ◽  
Long Wave ◽  
Surface Cyclone ◽  
The Difference ◽  
Upper Level

Abstract To investigate the role of synoptic-scale processes in regulating the strength of the dryline, a dataset is constructed of all drylines occurring within the West Texas Mesonet (WTM) during April, May, and June of 2004 and 2005. In addition, dewpoint and wind data were collected from stations on the western (Morton; MORT) and eastern (Paducah; PADU) periphery of the WTM domain (230 km across), generally oriented east–west across the typical location of the dryline in west Texas. Drylines were characterized by two variables: the difference in dewpoint between MORT and PADU (hereafter, dryline intensity) and the difference in the eastward component of the wind between MORT and PADU (hereafter, dryline confluence). A high degree of correlation existed between the two variables, consistent with a strong role for dryline confluence in determining dryline intensity. Some cases departing from the strong correlation between these variables represent synoptically quiescent drylines whose strength is likely dominated by boundary layer mixing processes. Composite synoptic analyses were constructed of the upper and lower quartiles of dryline intensity, termed STRONG and WEAK, respectively. STRONG drylines were associated with a short-wave trough in the upper-level westerlies approaching west Texas, an accompanying surface cyclone over eastern New Mexico, and southerly flow over the south-central United States. This synoptic environment was favorable for enhancing the dryline confluence responsible for strengthening the dryline. In contrast, WEAK drylines were associated with an upper-level long-wave ridge over Texas and New Mexico, broad surface cyclogenesis over the southwestern United States, and a weak lee trough—the dryline confluence favorable for dryline intensification was much weaker. A third composite termed NO BOUNDARY was composed of dates with no surface airstream boundary (e.g., front, dryline) in the WTM domain. The NO BOUNDARY composite featured an upper-level long-wave ridge west of Texas and no surface cyclone or lee trough. The results of this study demonstrate the important role that synoptic-scale processes (e.g., surface lee troughs, upper-level short-wave troughs) play in regulating the strength of the dryline. Once such a favorable synoptic pattern occurs, mesoscale and boundary layer processes can lead to further intensification of the dryline.

scholarly journals Social media privacy concerns and risk beliefs

2019 ◽  
Vol 7 (1) ◽  
pp. 1-13
Author(s):  
Johnathan Yerby ◽  
Alex Koohang ◽  
Joanna Paliszkiewicz
Keyword(s):  
United States ◽  
Social Media ◽  
Social Networking ◽  
Personal Information ◽  
Southeastern United States ◽  
Social Networking Site ◽  
Future Research ◽  
Privacy Concerns ◽  
Risk Beliefs ◽  
The Social

The purpose of this study was to investigate the link between users’ risk beliefs and social media privacy concerns (concerns users express regarding social media sites’ practices as to how they collect and use personal information). A Likert-type instrument with seven constructs, six of which described the social media privacy concerns and the seventh construct defined users’ risk beliefs, was used to collect data from students who were studying at a university in the southeastern United States. All students (N = 138) used Facebook as their major social networking site. Collected data were analyzed via multiple regression analysis. The results indicated that subjects’ risk beliefs are influenced by three social media privacy concerns (i.e., collection, error, and awareness). The Findings and their implications are discussed. Recommendations for future research are made.

Tolerance of pintoi peanut to PRE and POST herbicides

2020 ◽  
Vol 34 (6) ◽  
pp. 870-875
Author(s):  
Logan J. Martin ◽  
José Luiz C.S. Dias ◽  
Brent A. Sellers ◽  
Jason A. Ferrell ◽  
Ramon G. Leon ◽  
...  
Keyword(s):  
United States ◽  
Weed Management ◽  
Southeastern United States ◽  
Warm Season ◽  
Future Research ◽  
Herbicide Application ◽  
Forage Crop ◽  
Herbicide Treatments ◽  
Perennial Legume ◽  
Significant Injury

AbstractPintoi peanut is a warm-season perennial legume that shows promise as a forage crop for the southeastern United States, however, little is known about the proper methods of weed management during establishment for this species. The objective of this study was to determine the ability of pintoi peanut to tolerate applications of PRE and POST herbicides during the year of and year after planting. The effects of herbicide treatments on percentage of visual estimates of injury and stand counts of pintoi peanut were investigated at Ona and Marianna, FL, in 2015 and 2016. All PRE herbicides did not result in significant injury or stand reduction. Pintoi peanut’s tolerance to POST herbicides was higher when plants were emerged for at least 2 wk prior to herbicide application. Stands of pintoi peanut that were planted the previous year appear to tolerate all herbicides examined in this work, except sulfosulfuron. Results of this study indicate that at the year of planting pintoi peanut is tolerant to PRE applications of pendimethalin, imazethapyr, and imazapic. Pintoi peanut appears to tolerate applications of 2,4-D, carfentrazone, imazapic and imazethapyr the year after planting at the rates utilized in this study. Future research should evaluate the effects of multiple herbicide applications and tank-mixes to obtain satisfactory weed control and selectivity in pintoi peanut swards.

scholarly journals The Relationship between Political Orientation and Race on Modern Racism

2015 ◽  
Vol 3 (1) ◽  
pp. 67
Author(s):  
David Bryan Oxendine
Keyword(s):  
United States ◽  
Graduate Students ◽  
Southeastern United States ◽  
Ethnically Diverse ◽  
Political Orientation ◽  
Future Research ◽  
Factors Associated ◽  
Modern Racism ◽  
Regional University ◽  
The Relationship

<p>Political orientation and race have consistently found to be associated with attitudes leading to the foundational elements underpinning prejudice. This study investigates these relationships more fully in order to determine the magnitude of these relationships leading to modern racist attitudes. The research participants consisted of 225 undergraduate and graduate students at an ethnically diverse regional university in the southeastern United States. Consistent with existing literature, White participants reported greater levels of modern racist attitudes than did Non-White participants. As hypothesized, political orientation and race significantly related to modern racist attitudes. Implications for continuing future research on political orientation, race and other factors associated with modern racism.</p>

scholarly journals The Effectiveness of Forestry Best Management Practices for Sediment Control in the Southeastern United States: A Literature Review

2011 ◽  
Vol 35 (4) ◽  
pp. 170-177 ◽  
Author(s):  
Christopher J. Anderson ◽  
B. Graeme Lockaby
Keyword(s):  
United States ◽  
Best Management Practices ◽  
Management Practices ◽  
Southeastern United States ◽  
Future Research ◽  
Sediment Retention ◽  
Sediment Control ◽  
Best Management ◽  
Wide Range ◽  
Bmp Effectiveness

Abstract Water quality from forested watersheds (both managed and unmanaged) is normally very good and better than most other human-dominated land uses. Water degradation is possible during forestry operations; however, the use of best management practices (BMP) has been shown to substantially reduce the risk. In the southeastern United States, forests are managed under a wide range of conditions reflective of physiographic region, soil erodibility, climate, and site wetness. Although it is clear that BMP reduce sediment and pollutant loading into streams, there is less information regarding how effective these practices are (i.e., how much sediment did BMP retain? What was the mechanism for sediment retention?). A review of the scientific literature was conducted to evaluate forestry BMP effectiveness to control sediment in the southeastern United States. Our reviewly quantified BMP effectiveness to reduce sediment. In the Coastal Plain, research has focused on forest roads and site wetness, whereas in the Piedmont and regions with steeper terrain, the focus has been on streamside management zones. These studies provide an initial indication of how much sediment is reduced by BMP; however, more information is needed for managers to make reasonable estimations. Future research should focus on quantifying BMP effects on sediment yield and identifying the specific mechanisms involved.

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