Contiguous US summer maximum temperature and heat stress trends in CRU and NOAA Climate Division data plus comparisons to reanalyses

Abstract Episodes of heat stress constrain crop production and will be aggravated in the near future according to short and medium-term climate scenarios. Global increase in cloudiness has also been observed, decreasing the incident solar radiation. This work was aimed to quantify the probability of occurrence of heat stress and cloudiness, alone or combined, during the typical post-flowering period of wheat and canola in the Southern Cone of South America. Extended climate series (last 3-5 decades with daily register) of 33 conventional weather stations from Argentina, Brazil, Chile and Uruguay (23ºS to 40ºS) were analysed considering the period from September to December. Two different daily events of heat stress were determined: i) maximum daily temperature above 30ºC (T>30ºC), and ii) 5ºC above the historical average maximum temperature of that day (T+5ºC). A cloudiness event was defined in our work as incident solar radiation 50% lower than the historical average radiation of that day (R50%). The T>30ºC event increased its probability of occurrence throughout the post-flowering phase, from September to December. By contrast, the risk of T+5ºC event decreased slightly, just like for R50%, and the higher the latitude, the lower the probability of R50%. The T>30ºC plus R50% combined stresses reached greater cumulated probabilities during post-flowering, compared to T+5ºC plus R50%, being 42% vs. 15% in northernmost locations, 26% vs. 19% in central (between 31ºS to 35ºS), and 28% vs. 1% in southernmost locations, respectively. A curvilinear relationship emerged between the monthly probability of combined stresses and the number of days with stress per month. In summary, T>30ºC was the most frequent thermal stress during post-flowering in wheat and canola. Both combined stresses had a noticeable risk of occurrence, but T>30ºC plus R50% was the highest. Evidence of the recent past and current occurrence of heat stress individually, and its combination with cloudiness events during post-flowering of temperate crops, serves as a baseline for future climate scenarios in main cropped areas in the Southern Cone of South America.

Download Full-text

To Provide a Double Feeder in Growing Pigs Housed under High Environmental Temperatures Reduces Social Interactions but Does Not Improve Weight Gains

Animals ◽

10.3390/ani10122248 ◽

2020 ◽

Vol 10 (12) ◽

pp. 2248

Author(s):

Tâmara Duarte Borges ◽

Mariana Huerta-Jimenez ◽

Nicolau Casal ◽

Joel Gonzalez ◽

Nuria Panella-Riera ◽

...

Keyword(s):

Body Weight ◽

Heat Stress ◽

Social Interactions ◽

Growing Pigs ◽

Maximum Temperature ◽

Lower Body Weight ◽

Body Weights ◽

Weight Gains ◽

Feeding Area ◽

Environmental Temperatures

Heat stress and competition for food are two major challenges in pigs reared in intensive conditions. The aim of the present work was to study the effect of providing a double feeder for pigs reared under two different environmental temperatures. In addition, two types of flooring, of 100% slat and 30% slat 70% concrete, were also considered. A total of 256 pigs in the growing-finishing period (from 27 kg to 110 kg) were housed using two environmental temperatures: control (from 18 °C to 25 °C) and heat stress (above 30 °C six hours a day). They were housed in 32 pens of 8 pigs each, distributed into 4 rooms (16 with one feeder and 16 with two). Pigs subjected to temperatures above 30 °C up to six hours had lower body weight gains than pigs subjected to a maximum temperature of 25 °C, confirming that thermal stress negatively affects performance in pigs. In addition, heat stress affected the final product by decreasing the lean percentage of carcasses by 2.6%. A double feeder reduced the presence of negative social behavior, especially in the feeding area, but body weight was lower than when one single feeder was used. A 30% slat 70% concrete floor showed better results in the pig stress indicators and body weights than 100% slat. It is concluded that providing a double feeder in the pens, although reducing the presence of negative social interactions, negatively affected body weight, in comparison to pigs fed with just one feeder.

Download Full-text

Hydration of the lower stratosphere by ice crystal geysers over land convective systems

Atmospheric Chemistry and Physics ◽

10.5194/acp-9-2275-2009 ◽

2009 ◽

Vol 9 (6) ◽

pp. 2275-2287 ◽

Cited By ~ 75

Author(s):

S. Khaykin ◽

J.-P. Pommereau ◽

L. Korshunov ◽

V. Yushkov ◽

J. Nielsen ◽

...

Keyword(s):

Water Vapour ◽

Lower Stratosphere ◽

Monsoon Season ◽

Extreme Case ◽

Fast Response ◽

Maximum Temperature ◽

Ice Crystal ◽

Convective Systems ◽

Mesoscale Convective ◽

Summer Maximum

Abstract. The possible impact of deep convective overshooting over land has been explored by six simultaneous soundings of water vapour, particles and ozone in the lower stratosphere next to Mesoscale Convective Systems (MCSs) during the monsoon season over West Africa in Niamey, Niger in August 2006. The water vapour measurements were carried out using a fast response FLASH-B Lyman-alpha hygrometer. The high vertical resolution observations of the instrument show the presence of accumulation of enhanced water vapour layers between the tropopause at 370 K and the 420 K level. Most of these moist layers are shown connected with overshooting events occurring upwind as identified from satellite IR images over which the air mass probed by the sondes passed during the three previous days. In the case of a local overshoot identified by echo top turrets above the tropopause by the MIT C-band radar also in Niamey, tight coincidence was found between enhanced water vapour, ice crystal and ozone dip layers indicative of fast uplift of tropospheric air across the tropopause. The water vapour mixing ratio in the enriched layers exceeds frequently by 1–3 ppmv the average 6 ppmv saturation ratio at the tropopause and by up to 7 ppmv in the extreme case of local storm in coincidence with the presence of ice crystals. The presence of such layers strongly suggests hydration of the lower stratosphere by geyser-like injection of ice particles over overshooting turrets. The pile-like increase of water vapour up to 19 km seen by the high-resolution hygrometer during the season of maximum temperature of the tropopause, suggests that the above hydration mechanism may contribute to the summer maximum moisture in the lower stratosphere. If this interpretation is correct, hydration by ice geysers across the tropopause might be an important contributor to the stratospheric water vapour budget.

Download Full-text

Evaluation of trends in extreme temperatures simulated by HighResMIP models across Europe

10.5194/egusphere-egu2020-21769 ◽

2020 ◽

Author(s):

Gerard van der Schrier ◽

Antonello Squintu ◽

Else van den Besselaar ◽

Eveline van der Linden ◽

Enrico Scoccimarro ◽

...

Keyword(s):

High Resolution ◽

Western Europe ◽

Extreme Values ◽

Maximum Temperature ◽

Western Balkans ◽

North West ◽

The Balkans ◽

The North ◽

Summer Maximum ◽

Maximum Temperatures

The comparison of simulated climate with observed daily values allows to assess their reliability and the soundness of their projections on the climate of the future. Frequency and amplitude of extreme events are fundamental aspects that climate simulations need to reproduce. In this work six models developed within the High Resolution Model Intercomparison Project are compared over Europe with the homogenized version of the observational E-OBS gridded dataset. This is done by comparing averages, extremes and trends of the simulated summer maximum temperature and winter minimum temperatures with the observed ones.Extreme values have been analyzed making use of indices based on the exceedances of percentile-based thresholds. Winter minimum temperatures are generally underestimated by models in their averages (down to -4 deg. C of difference over Italy and Norway) while simulated trends in averages and extreme values are found to be too warm on western Europe and too cold on eastern Europe (e.g. up to a difference of -4% per decade on the number of Cold Nights over Spain). On the other hand the models tend to underestimate summer maximum temperatures averages in Northern Europe and overestimate them in the Mediterranean areas (up to +5 deg. C over the Balkans). The simulated trends are too warm on the North West part and too cold on the South East part of Europe (down to -3%/dec. on the number of Warm Days over Italy and Western Balkans).These results corroborate the findings of previous studies about the underestimation of the warming trends of summer temperatures in Southern Europe, where these are more intense and have more impacts. &#160;A comparison of the high resolution models &#160;with the corresponding version in CMIP5 has been performed comparing the absolute biases of extreme values trends. This has shown a slight improvement for the simulation of winter minimum temperatures, while no signs of significant progresses have been found for summer maximum temperatures.

Download Full-text

Summer infertility in pigs: its incidence and characteristics in an Australian commercial piggery

Australian Journal of Experimental Agriculture ◽

10.1071/ea9780698 ◽

1978 ◽

Vol 18 (94) ◽

pp. 698 ◽

Cited By ~ 28

Author(s):

AM Paterson ◽

I Barker ◽

DR Lindsay

Keyword(s):

Heat Stress ◽

High Temperature ◽

Litter Size ◽

Ovarian Function ◽

Embryonic Mortality ◽

Maximum Temperature ◽

Daily Maximum Temperature ◽

Daily Maximum ◽

Fertilization Failure ◽

Summer Temperatures

The records of five years' production in an 800 sow commercial piggery were examined and the relationships between summer temperatures, returns to service and litter size were considered. When mean daily maximum temperature exceeded 32�C during the week of service there was an increase in the number of sows failing to hold to service. The number of sows that returned to service 15-25 days after mating remained constant throughout the year, and summer infertility was characterized by an increase in the number of sows that exhibited extended, irregular return-to-service intervals. The litter size of sows that conceived during the period of summer infertility was not significantly different from that of sows conceiving at other times of the year. The data suggest that summer infertility is not due simply to fertilization failure, embryonic mortality or an increased incidence of abortions in sows mated during periods of high temperature. Neither does boar fertility appear to be in question. It seems most likely that heat stress around the time of mating may affect ovarian function, resulting in temporary infertility and an endocrine imbalance, which causes delayed, irregular returns to oestrus.

Download Full-text

MITIGATION OF HEAT STRESS EFFECTS ON POTATO GROWTH BY CALCIUM AND NITROGEN APPLICATION DURING STRESS

HortScience ◽

10.21273/hortsci.27.6.596f ◽

1992 ◽

Vol 27 (6) ◽

pp. 596f-596 ◽

Cited By ~ 1

Author(s):

Ahmed A. Tawfik ◽

Jiwan P. Palta

Keyword(s):

Heat Stress ◽

Sandy Loam ◽

Leaf Tissue ◽

Maximum Temperature ◽

N Application ◽

Total N ◽

Stress Effects ◽

Loam Soil ◽

Potato Growth ◽

The Impact

The optimum temperature regime for Solanum tuberosum cv. Russet Burbank is usually 20/15°C day/night. We studied the impact of heat stress (30/25°C, day/night) on the growth of this heat sensitive cultivar under controlled conditions (UW-Biotron). Plants were grown in sandy-loam soil which tested at 1500 Kg/ha Ca. Plants were at the maximum temperature for 6h during the middle of the day with a photoperiod of 14 hrs. All pots received identical amounts of total N (rate: 225 Kg N ha1.). The treatments were: (1) NSN: non-split N (N application 1/2 emergence, 1/2 two wks later): (2) SPN: split-N (1/2 emergence 1/6 at 2, 5 and 8 wks later); (3) SPN+Ca: Split-N+Ca (Ca at 2, 5 and 8 wks after emergence, total Ca from CaNO3 was 113 Kg ha1). Total leaf FWT and DWT was significantly reduced in NS treatment by heat stress at 13 wks as compared to optimum conditions. However, this was not reduced in SPN and SPN+Ca. Under heat stress: (a) SPN + Ca gave the highest leaf FWT and DWT, stomatal conductance, transpiration rate, and leaflet tissue Ca content; (b) Young expanding leaflets gave higher growth rate with SPN and SPN + Ca than NSN; (c) Ca content of mature leaflet decreased progressively in both NSN and SPN but not in SPN + Ca. Our results show that application of Ca and N during heat stress can mitigate stress effects and that maintenance of a certain level of calcium in leaf tissue is important under heat stress.

Download Full-text

An Evaluation of Temperature-Based Agricultural Indices Over Korea From the High-Resolution WRF Simulation

Frontiers in Earth Science ◽

10.3389/feart.2021.656787 ◽

2021 ◽

Vol 9 ◽

Author(s):

Eun-Soon Im ◽

Subin Ha ◽

Liying Qiu ◽

Jina Hur ◽

Sera Jo ◽

...

Keyword(s):

Heat Stress ◽

High Resolution ◽

Dynamical Downscaling ◽

Initial Conditions ◽

Added Value ◽

Stress Index ◽

Maximum Temperature ◽

Daily Maximum Temperature ◽

Daily Maximum ◽

Hourly Temperature

This study evaluates the performance of dynamical downscaling of global prediction generated from the NOAA Climate Forecast System (CFSv2) at subseasonal time-scale against dense in-situ observational data in Korea. The Weather Research and Forecasting (WRF) double-nested modeling system customized over Korea is adopted to produce very high resolution simulation that presumably better resolves geographically diverse climate features. Two ensemble members of CFSv2 starting with different initial conditions are downscaled for the summer season (June-July-August) during past 10-year (2011–2020). The comparison of simulations from the nested domain (5 km resolution) of WRF and driving CFSv2 (0.5°) clearly demonstrates the manner in which dynamical downscaling can drastically improve daily mean temperature (Tmean) and daily maximum temperature (Tmax) in both quantitative and qualitative aspects. The downscaled temperature not only better resolves the regional variability strongly tied with topographical elevation, but also substantially lowers the systematic cold bias seen in CFSv2. The added value from the nested domain over CFSv2 is far more evident in Tmax than in Tmean, which indicates a skillful performance in capturing the extreme events. Accordingly, downscaled results show a reasonable performance in simulating the plant heat stress index that counts the number of days with Tmax above 30°C and extreme degree days that accumulate temperature exceeding 30°C using hourly temperature. The WRF simulations also show the potential to capture the variation of Tmean-based index that represents the accumulation of heat stress in reproductive growth for the mid-late maturing rice cultivars in Korea. As the likelihood of extreme hot temperatures is projected to increase in Korea, the modeling skill to predict the ago-meteorological indices measuring the effect of extreme heat on crop could have significant implications for agriculture management practice.

Download Full-text

Untangling the Influence of Heat Stress on Crop Phenology, Seed Set, Seed Weight, and Germination in Field Pea (Pisum sativum L.)

Frontiers in Plant Science ◽

10.3389/fpls.2021.635868 ◽

2021 ◽

Vol 12 ◽

Author(s):

Amrit Lamichaney ◽

Ashok K. Parihar ◽

Kali K. Hazra ◽

Girish P. Dixit ◽

Pradip K. Katiyar ◽

...

Keyword(s):

Heat Stress ◽

High Temperature ◽

Seed Germination ◽

Temperature Stress ◽

Seed Weight ◽

Seed Set ◽

High Temperature Stress ◽

Field Pea ◽

Maximum Temperature ◽

100 Seed Weight

The apparent climatic extremes affect the growth and developmental process of cool-season grain legumes, especially the high-temperature stress. The present study aimed to investigate the impacts of high-temperature stress on crop phenology, seed set, and seed quality parameters, which are still uncertain in tropical environments. Therefore, a panel of 150 field pea genotypes, grouped as early (n = 88) and late (n = 62) maturing, were exposed to high-temperature environments following staggered sowing [normal sowing time or non-heat stress environment (NHSE); moderately late sowing (15 days after normal sowing) or heat stress environment-I (HSE-I); and very-late sowing (30 days after normal sowing) or HSE-II]. The average maximum temperature during flowering was about 22.5 ± 0.17°C for NHSE and increased to 25.9 ± 0.11°C and 30.6 ± 0.19°C in HSE-I and HSE-II, respectively. The average maximum temperature during the reproductive period (RP) (flowering to maturity) was in the order HSE-II (33.3 ± 0.03°C) > HSE-I (30.5 ± 0.10°C) > NHSE (27.3 ± 0.10°C). The high-temperature stress reduced the seed yield (24–60%) and seed germination (4–8%) with a prominent effect on long-duration genotypes. The maximum reduction in seed germination (>15%) was observed in HSE-II for genotypes with >115 days maturity duration, which was primarily attributed to higher ambient maximum temperature during the RP. Under HSEs, the reduction in the RP in early- and late-maturing genotypes was 13–23 and 18–33%, suggesting forced maturity for long-duration genotypes under late-sown conditions. The cumulative growing degree days at different crop stages had significant associations (p < 0.001) with seed germination in both early- and late-maturing genotypes; and the results further demonstrate that an extended vegetative period could enhance the 100-seed weight and seed germination. Reduction in seed set (7–14%) and 100-seed weight (6–16%) was observed under HSEs, particularly in HSE-II. The positive associations of 100-seed weight were observed with seed germination and germination rate in the late-maturing genotypes, whereas in early-maturing genotypes, a negative association was observed for 100-seed weight and germination rate. The GGE biplot analysis identified IPFD 11-5, Pant P-72, P-1544-1, and HUDP 11 as superior genotypes, as they possess an ability to produce more viable seeds under heat stress conditions. Such genotypes will be useful in developing field pea varieties for quality seed production under the high-temperature environments.

Download Full-text

Investigating Applicability of Evaporative Cooling Systems for Thermal Comfort of Poultry Birds in Pakistan

Applied Sciences ◽

10.3390/app10134445 ◽

2020 ◽

Vol 10 (13) ◽

pp. 4445

Author(s):

Hafiz M. U. Raza ◽

Hadeed Ashraf ◽

Khawar Shahzad ◽

Muhammad Sultan ◽

Takahiko Miyazaki ◽

...

Keyword(s):

Heat Stress ◽

Thermal Comfort ◽

Developing Economies ◽

Low Cost ◽

Evaporative Cooling ◽

Ambient Air ◽

Climatic Conditions ◽

Maximum Temperature ◽

Poultry Birds ◽

The City

In the 21st century, the poultry sector is a vital concern for the developing economies including Pakistan. The summer conditions of the city of Multan (Pakistan) are not comfortable for poultry birds. Conventionally, swamp coolers are used in the poultry sheds/houses of the city, which are not efficient enough, whereas compressor-based systems are not economical. Therefore, this study is aimed to explore a low-cost air-conditioning (AC) option from the viewpoint of heat stress in poultry birds. In this regard, the study investigates the applicability of three evaporative cooling (EC) options, i.e., direct EC (DEC), indirect EC (IEC), and Maisotsenko-cycle EC (MEC). Performance of the EC systems is investigated using wet-bulb effectiveness (WBE) for the climatic conditions of Multan. Heat stress is investigated as a function of poultry weight. Thermal comfort of the poultry birds is calculated in terms of temperature-humidity index (THI) corresponding to the ambient and output conditions. The heat production from the poultry birds is calculated using the Pederson model (available in the literature) at various temperatures. The results indicate a maximum temperature gradient of 10.2 °C (MEC system), 9 °C (DEC system), and 6.5 °C (IEC systems) is achieved. However, in the monsoon/rainfall season, the performance of the EC systems is significantly reduced due to higher relative humidity in ambient air.

Download Full-text

Summer maximum temperature over the gulf cooperation council states in the twenty-first century: multimodel simulations overview

Arabian Journal of Geosciences ◽

10.1007/s12517-020-05537-x ◽

2020 ◽

Vol 13 (12) ◽

Cited By ~ 2

Author(s):

Mansour Almazroui

Keyword(s):

Gulf Cooperation Council ◽

Global Climate Models ◽

First Century ◽

Maximum Temperature ◽

Daily Maximum Temperature ◽

Daily Maximum ◽

Gcc Countries ◽

The Future ◽

Summer Maximum ◽

Twenty First Century

Abstract The present study analyzes the Survivability for a Fit Human Threshold (SFHT) maximum temperature during the summer (June–August) over the six Middle Eastern countries known as the Gulf Cooperation Council (GCC) in the twenty-first century. An ensemble of three dynamically downscaled global climate models available from the Coupled Model Intercomparison Project Phase 5 (CMIP5) under the Representative Concentration Pathways (RCPs) RCP4.5 and RCP8.5 emission scenarios is used to analyze the future climate (2006–2099) over the region. The ground-truth air temperature for ten major cities across the GCC countries is utilized for model evaluation and to estimate the model-simulated temperature biases. Both positive and negative biases found during the present climate (1976–2005) are used to adjust the future temperature changes. These adjustments show that the summer maximum temperature is likely to increase continuously for most cities in the GCC countries at the rate of about 0.2 °C (0.6 °C) per decade under RCP4.5 (RCP8.5) for the future period (2020–2099), which is significant at the 99% confidence level. For RCP8.5, the adjusted summer maximum temperature may exceed the SFHT limit of 42 °C in five capital cities of the GCC states and four major cities of Saudi Arabia. The projections based on adjusted values indicate that the average summer maximum temperature should not exceed 52 °C in any city investigated by the end of the twenty-first century. The daily maximum temperature is projected to exceed 55 °C in some cities in the GCC region by the end of the twenty-first century under a business-as-usual scenario that seems to be unrealistic if the biases are not taken into account. It is highly recommended that the GCC states should coordinate their efforts to respond appropriately to these projections using large ensembles of multimodel simulations while allowing for the associated uncertainty.

Download Full-text