scholarly journals The Effects of Heat Stress on Photosynthesis of Coreopsis grandiflora `Sunray' and Gaillardia ×grandiflora `Goblin'

HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 551B-551a
Author(s):  
Melyssa K. Davis ◽  
Jeff S. Kuehny
Keyword(s):  
United States ◽  
High Temperature ◽  
The United States ◽  
Time Of Day ◽  
Flower Senescence ◽  
Optimal Conditions ◽  
Herbaceous Perennials ◽  
Current Production ◽  
Rate Of Photosynthesis ◽  
Heat Tolerant

Herbaceous perennials are one of the fastest growing ornamental sectors in the United States. Current production recommendations do not address the effect of environmental factors, such as high temperature, on growth of herbaceous perennials. The focus of this research was to determine how supra-optimal temperatures effect growth and photosynthesis. Plants were exposed to a high temperature of 35 °C and photosynthesis measurements were recorded over a 6-week period at 1100, 1300, and 1500 hr. Results indicate that the time of day the measurements were taken made little difference on rate of photosynthesis and that there was a similar trend in photosynthetic rate over the 6-week period. Photosynthesis decreased as the plants began to flower and then increased until the onset of flower senescence. Plants grown at supraoptimal and optimal conditions had a similar trend and rate of photosynthesis throughout the 6-week period. Plant growth significantly decreased as the duration of high temperature increased for both species; however, Gaillardia was more heat tolerant then Coreopsis.

scholarly journals 151 The Effect of Supro-optimal Temperature on Photosynthesis, Carbohydrate Allocation, Flowering, and Growth of Coreopsis grandiflora `Sunray' AND Gaillardia × grandiflora `Goblin'

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 415E-416
Author(s):  
Melyssa K. Davis ◽  
Jeff S. Kuehny
Keyword(s):  
High Temperature ◽  
Time Of Day ◽  
Flower Senescence ◽  
Flower Initiation ◽  
Optimal Conditions ◽  
Optimal Temperature ◽  
Carbohydrate Partitioning ◽  
Total Carbohydrates ◽  
Rate Of Photosynthesis ◽  
Heat Tolerant

Coreopsis and Gaillardia were exposed to supra-optimal temperatures of 35 °C for a 6-week period beginning at flower initiation. Photosynthesis measurements were recorded at 1100 hr, 1300 hr, and 1500 hr for 3 days each week and carbohydrate partitioning was determined once per week. Results indicate that the time of day the measurements were taken made little difference on rate of photosynthesis and that there was a similar trend in photosynthetic rate over the 6-week period. Photosynthesis decreased as the plants began to flower and then increased until the onset of flower senescence. The patterns of carbohydrate partitioning were similar to those observed for photosynthesis. The plants grown at supra-optimal and optimal conditions had a similar trend and rate of photosynthesis throughout the 6-week period. Plant growth and total carbohydrates significantly decreased as the duration of high temperature increased for both species, however Gaillardia was more heat tolerant than Coreopsis.

Assessment of Moderate- and High-Temperature Geothermal Resources of the United States

Fact Sheet ◽  
2008 ◽  
Author(s):  
Colin F. Williams ◽  
Marshall J. Reed ◽  
Robert H. Mariner ◽  
Jacob DeAngelo ◽  
S. Peter Galanis
Keyword(s):  
United States ◽  
High Temperature ◽  
The United States ◽  
Geothermal Resources

scholarly journals 692. Effects of Regional Climatic Variability on West Nile Virus Outbreaks in the United States

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S249-S250
Author(s):  
Raghesh Varot Kangath ◽  
Buddhika Maduraperuma ◽  
Juliana Souza Borges ◽  
Rajasreepai Ramachandrapai
Keyword(s):  
United States ◽  
High Temperature ◽  
Population Density ◽  
Climatic Variability ◽  
The United States ◽  
Climatic Data ◽  
Cca Ordination ◽  
Neuroinvasive Disease ◽  
South Central ◽  
Risk Areas

Abstract Background Transmission of WNV to humans in the United States typically occurs between June and September since warm temperatures accelerate mosquito life cycle. Precipitation can cause increase in aquatic breeding but outbreaks often depends upon human water management. We examine epidemiology, patterns of WNV disease transmission, and identification of high-risk areas in the United States from 2003 to 2014. Methods Trends and relationships of WNV cases and climatic factors were analyzed among the regions of the United States from 2003 to 2014. Human WNV tabulate data and climatic data were obtained from Centers for Disease Control, and NOAA and Climate Data Guide, respectively. Canonical correspondence analysis (CCA) was performed using variables: (i) neuroinvasive disease cases, non-neuroinvasive disease cases, deaths, presumptiveviremic blood donors, (ii) precipitation, temperature, Palmer Drought Severity Index (PDSI) and population density. The CCA ordination was explained the variability between WNV disease cases andclimatic variables. Biplots were used to visualize the associations between WNV cases and climatic anomalies. Results We compared the state wise WNV disease cases in relation to climatic and population density in the United States from 2003 to 2014. A total of 4,064 cases in 2006, 956 cases in 2010 and, 2,141 cases in 2014 were reported in the 32 states of the United States. Colorado state reported the highest WNV cases in 2003 (2,947 cases; 33%), followed by Texas in 2012 (1,868 cases; 35%) and California in 2014 (801 case; 37%). CCA ordination showed distinguishable clustering patterns between south central (Texas, Louisiana, Mississippi, Arkansas, and Oklahoma) and northern Great Plains (North Dakota, South Dakota, and Nebraska) regions (Figure 1). High temperature and prolong drought were the most important variable predictor for high WNV outbreak. Conclusion Vector control methods focusing on prevention must be implemented to avoid epidemics of WNV if high temperature is leading to an unusual drought especially at the risk areas, such as Texas and California. However, high temperature with moist spell anomalies in the south central region showed a negative influence on WNV outbreak. Disclosures All authors: No reported disclosures.

Prediction of Flash Droughts over the United States

2020 ◽  
Vol 21 (8) ◽  
pp. 1793-1810
Author(s):  
Kingtse C. Mo ◽  
Dennis P Lettenmaier
Keyword(s):  
United States ◽  
Soil Moisture ◽  
High Temperature ◽  
Pacific Northwest ◽  
Heat Wave ◽  
Late Summer ◽  
The United States ◽  
Late Spring ◽  
The North ◽  
June July

AbstractWe examine reforecasts of flash droughts over the United States for the late spring (April–May), midsummer (June–July), and late summer/early autumn (August–September) with lead times up to 3 pentads based on the NOAA second-generation Global Ensemble Forecast System reforecasts version 2 (GEFSv2). We consider forecasts of both heat wave and precipitation deficit (P deficit) flash droughts, where heat wave flash droughts are characterized by high temperature and depletion of soil moisture and P deficit flash droughts are caused by lack of precipitation that leads to (rather than being the cause of) high temperature. We find that the GEFSv2 reforecasts generally capture the frequency of occurrence (FOC) patterns. The equitable threat score (ETS) of heat wave flash drought forecasts for late spring in the regions where heat wave flash droughts are most likely to occur over the north-central and Pacific Northwest regions is statistically significant up to 2 pentads. The GEFSv2 reforecasts capture the basic pattern of the FOC of P-deficit flash droughts and also are skillful up to lead about 2 pentads. However, the reforecasts overestimate the P-deficit flash drought FOC over parts of the Southwest in late spring, leading to large false alarm rates. For autumn, the reforecasts underestimate P-deficit flash drought occurrence over California and Nevada. The GEFSv2 reforecasts are able to capture the approximately linear relationship between evaporation and soil moisture, but the lack of skill in precipitation forecasts limits the skill of P-deficit flash drought forecasts.

High-Temperature Applications of Intermetallic Compounds

MRS Bulletin ◽  
1996 ◽  
Vol 21 (5) ◽  
pp. 30-36 ◽  
Author(s):  
David P. Pope ◽  
Ram Darolia
Keyword(s):  
United States ◽  
High Temperature ◽  
Intermetallic Compounds ◽  
Weight Ratio ◽  
The United States ◽  
Material System ◽  
National Defense ◽  
New Materials ◽  
Solid Solution Matrix ◽  
High Level

One of the greatest challenges currently facing the materials community is the need to develop a new generation of materials to replace Ni-based superalloys in the hot sections of gas-turbine engines for aircraft-propulsion systems. The present alloys, which have a Ni-based solid-solution matrix surrounding Ni3Al-based precipitates, are currently used at temperatures exceeding 1100°C, which is over 80% of the absolute melting temperature. Since Ni3Al melts at 1395°C and Ni at 1453°C, it is clear that significantly higher operating temperatures, with the attendant improvements in efficiency and thrust-to-weight ratio, can only be attained by the development of an entirely new materials system. This problem is a primary reason for the current high level of interest in high-temperature intermetallic compounds.The development of such a material system has important implications for national defense and for spin-offs to civilian technology, as well as for the economy and balance of payments. Obviously it would be a boon to any economy to have these new materials developed domestically, as was the case in the United States for the currently used single-crystal technology applied to Ni-based superalloys. As an example, the aerospace industry is one area where the United States is still the undisputed world leader, with net exports of $29 billion in 1989, twice that of any other U.S. industry.

scholarly journals On the Anomalous Counterclockwise Turning of the Surface Wind with Time in the Plains of the United States

2018 ◽  
Vol 146 (2) ◽  
pp. 467-484 ◽  
Author(s):  
Howard B. Bluestein ◽  
Glen S. Romine ◽  
Richard Rotunno ◽  
Dylan W. Reif ◽  
Christopher C. Weiss
Keyword(s):  
United States ◽  
Boundary Layer ◽  
Great Plains ◽  
Surface Wind ◽  
Vertical Mixing ◽  
The United States ◽  
Time Of Day ◽  
Boundary Layer Transition ◽  
Vertical Shear ◽  
Layer Transition

Vertical shear in the boundary layer affects the mode of convective storms that can exist if they are triggered. In western portions of the southern Great Plains of the United States, vertical shear, in the absence of any transient features, changes diurnally in a systematic way, thus leading to a preferred time of day for the more intense modes of convection when the shear, particularly at low levels, is greatest. In this study, yearly and seasonally averaged wind observations for each time of day are used to document the diurnal variations in wind at the surface and in the boundary layer, with synoptic and mesoscale features effectively filtered out. Data from surface mesonets in Oklahoma and Texas, Doppler wind profilers, instrumented tower data, and seasonally averaged wind data for each time of day from convection-allowing numerical model forecasts are used. It is shown through analysis of observations and model data that the perturbation wind above anemometer level turns in a clockwise manner with time, in a manner consistent with prior studies, yet the perturbation wind at anemometer level turns in an anomalous, counterclockwise manner with time. Evidence is presented based on diagnosis of the model forecasts that the dynamics during the early evening boundary layer transition are, in large part, responsible for the behavior of the hodographs at that time: as vertical mixing in the boundary layer diminishes, the drag on the wind at anemometer level persists, leading to rapid deceleration of the meridional component of the wind. This deceleration acts to turn the wind to the left rather than to the right, as would be expected from the Coriolis force alone.

scholarly journals Tornado fatalities in context: 1995--2018

2021 ◽  
Author(s):  
Tyler Fricker ◽  
Corey Friesenhahn
Keyword(s):  
United States ◽  
The United States ◽  
Time Of Day ◽  
Fatality Rate ◽  
Quantitative Evidence ◽  
Emergency Managers ◽  
Level Information ◽  
Tornado Damage ◽  
The Relationship ◽  
Impact Events

Tornadoes account for the third highest average annual weather-related fatality rate in the United States. Here tornado fatalities are examined within the context of multiple physical and social factors using tornado level information related to population and housing units within killer tornado damage paths. The 24-year United States per-capita fatality rate is .32%. The per-housing unit fatality rate is .75%. Fatality rates are further evaluated across annual, monthly, and diurnal categorizations. They are also evaluated between fatality locations and across age and sex categorizations. The geographic distribution of fatalities are then given by season, time of day, and residential structures. Results can be used by emergency managers, meteorologists, and planners to better prepare for high-impact events and used by researchers as quantitative evidence to further investigate the relationship between tornadoes, climate, and society.

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