Chill Index Research Articles

Seasonal climate predictions for marine risk assessment in the Barents Sea

We investigate the potential for using seasonal climate predictions for marine risk assessment in the Barents Sea. Marine risk is based on the diagnostic of the probability of extreme climate conditions and their consequences to identify time and regions vulnerable to climate hazards. The information on marine risk is operationally provided by Det Norske Veritas (DNV) to support sustainable and safe marine activities. So far, the probability of climate conditions was based on historical observations. Here, we implement predicted probabilities from an ensemble of seasonal predictions provided by the German Meteorological Service. We analyze predicted probabilities for summer for three indicators from the DNV’s marine service: two of them represent meteorological properties such as wind speed and 2-meter temperature. The third indicator, the wind chill index (WCI), is a combination of the previous two. The prediction skill, the “trust level” for predictions, is assessed over 1990–2017 and suggests that 2-meter temperature has the highest skill followed by WCI and wind speed. In addition, we use a real-time prediction to represent an actual application example. The maps of the real-time predicted probabilities show that large areas of the Barents Sea represent favorable conditions for marine operations considering low likelihood for WCI above 1000 W/m2 and T2m below 0 °C in July and August. Wind speed is poorly predicted beyond the first forecast month. We describe the workflow for an application of seasonal predictions for the DNV’s marine service as well as lessons learned for similar applications involving risk assessment.

Stochastic Model of Conditional Non-stationary Time Series of the Wind Chill Index in West Siberia

In this paper, we propose a stochastic model of the conditional time series of the wind chill index. The model is based on the inverse distribution function method and on the normalization method for simulation of the non-Gaussian non-stationary random processes as well as on the method of conditional distributions for simulation of the conditional Gaussian processes. In the framework of the approach considered, two types of conditions (point conditions and interval conditions) are imposed on the time series. The model in question was verified using the real data collected at the weather stations located in West Siberia (Russia). It is shown that the simulated trajectories are close in their statistical properties to the real time series. The model proposed was used for stochastic forecasting of the wind chill index and the results of the numerical experiments have shown that the accuracy of the short-term forecasts is high enough.

Long term genetic selection for reproductive success affects neonatal lamb vitality across cold stress conditions.

Adverse weather conditions are important contributors to mortality in new-born lambs. Previous studies have shown variation between lambs in their ability to cope with circumstances of cold stress, and genetic selection could be a viable option for improving animal robustness. The Elsenburg Merino flock was divergently selected on number of lambs weaned (NLW). This resulted in divergent responses in reproduction and lamb survival. This study evaluated lamb vitality and mortality of positively selected H-Line relative to the negatively selected L-Line in response to cold stress. Traits included lamb rectal temperature (RT), surface temperature (ST), shiver score (SS), lamb vigor score (LVS), breaths per minute (BPM), mortality to three days of age (M3) and to weaning (TM). Cold stress was described by a chill index derived from daily rainfall, wind speed and ambient temperature, and represented as the mean of the one (CI), two (CI-2) or three (CI-3) days since parturition. Overall, H-Line lambs had a higher neonatal RT and were less likely to succumb than L-Line contemporaries. In a significant (P<0.05) interaction, the predicted RT of L-Line showed a non-linear decline with increased levels of CI-2, while H-Line lambs better maintained their core temperature. M3 was also affected by a significant interaction between CI-3 and selection line, further suggesting that observed lower mortality rates in the H-Line depends on H-Line lambs' improved ability to cope with stressful environments. Long term selection for NLW in the H-Line led to improvements in both adaptations associated with lower lamb losses. The continued recording of viability traits to produce larger datasets amenable to genetic analysis is recommended, specifically for rectal temperature.

Numerical stochastic modelling of spatial and spatio-temporal fields of the wind chill index in the South of Western Siberia

Abstract The paper presents the results of comparison of various methods of spatial interpolation of the wind chill index in two regions located in the South of Western Siberia (Russia). It is shown that stochastic interpolation provides the least interpolation error in the considered regions. The results of modelling the spatial and spatio-temporal fields of the considered bioclimatic index on a regular grid are presented.

A new framework to quantify maize production risk from chilling injury in Northeast China

Agricultural production frequently suffers from meteorological risks. Timely and accurately estimating yield losses will greatly improve disaster risk management, especially for a useful tool to transfer risks—agricultural insurance. The weather index insurance products have increasingly become promising alternatives to traditional ones. However, the current single-index insurances, mainly based on a statistical model with a lower explanation ability and at an aggregate scale (e.g. county, province), are lack of mechanistic processes and having huge basis risk. Here, we proposed a new framework to quantify maize production risk by running the well calibrated CERES-Maize driven by various chilling scenarios. We first analyzed the chilling risk across Northeast China, then developed a composite chilling index (CCI) and CCI-based vulnerability curves to derive the corresponding yield losses. Finally, the specific pure premium rates were calculated respectively at 16 sites across the studied areas. The results showed that composite-index insurance (RMSE¯ ≤ 721 kg/ha) outperformed (R2 improved by 35%) every single index (RMSE¯ ≈ 1140 kg/ha) in quantifying yield loss. We believe our proposed framework will benefit insurer companies rapidly estimating yield losses and designing more promising products, and potentially apply into other regions for other crops and hazards to transfer climate risk in the future.

Efficacy of warming systems in mountain rescue: an experimental manikin study

Mountain accident casualties are often exposed to cold and windy weather. This may induce post-traumatic hypothermia which increases mortality. The aim of this study was to assess the ability of warming systems to compensate for the victim’s estimated heat loss in a simulated mountain rescue operation. We used thermal manikins and developed a thermodynamic model of a virtual patient. Manikins were placed on a mountain rescue stretcher and exposed to wind chill indices of 0 °C and − 20 °C in a climatic chamber. We calculated the heat balance for two simulated clinical scenarios with both a shivering and non-shivering victim and measured the heat gain from gel, electrical, and chemical warming systems for 3.5 h. The heat balance in the simulated shivering patient was positive. In the non-shivering patient, we found a negative heat balance for both simulated weather conditions (− 429.53 kJ at 0 °C and − 1469.78 kJ at − 20 °C). Each warming system delivered about 300 kJ. The efficacy of the gel and electrical systems was higher within the first hour than later (p < 0.001). We conclude that none of the tested warming systems is able to compensate for heat loss in a simulated model of a non-shivering patient whose physiological heat production is impaired during a prolonged mountain evacuation. Additional thermal insulation seems to be required in these settings.

Stochastic Model of Spatial Fields of the Average Daily Wind Chill Index

The objective of this paper was to construct a numerical stochastic model of the spatial field of the average daily wind chill index on an irregular grid defined by the location of the weather stations. It is shown in the paper that the field in question was heterogeneous and non-Gaussian. A stochastic model based on the real data collected at the weather stations located in West Siberia and on the method of the inverse distribution function that sufficiently well reproduce different characteristics of the real field of the average daily wind chill index is proposed in this paper. I also discussed several questions related to the simulation of the field on a regular grid. In the future, my intention is to transform the model proposed to a model of the conditional spatio-temporal field defined on a regular grid that allows one to forecast the wind chill index.

Numerical Stochastic Model of Non-stationary Time Series of the Wind Chill Index

A numerical stochastic model of the high-resolution time series of the wind chill index is considered. The model is constructed under the assumption that time series of the wind chill index are non-stationary non-Gaussian random processes with time-dependent one-dimensional distributions. This assumption makes possible to take into account both daily and seasonal variations of real meteorological processes. Data of the long-term real observations at weather stations were used for estimating the model parameters and for the verification of the model. Based on the simulated trajectories, some statistical properties of rare and adverse weather events, like long periods of time with a low wind chill index, are studied. The model is also used to study the dependence of the statistical properties of the wind chill index time series on a climate change.

The effect of age, environment and management on social contact patterns in sheep

Social structures of group-living farm animals can have important implications for animal welfare and productivity. Understanding which factors can have an effect on social behaviour is thus important in order to develop the best management strategies in livestock industries. Here, we studied the social network structure of a flock of 84 Poll Dorset ewes and collecting dyadic associations data through the use of proximity sensors during two study periods. First, we analysed the social structure of ewes at a group-level, by analysing the community structure, and at individual-level, by determining whether the ewes showed social differentiation in their association patterns. Second, we measured for the contribution of genetic relatedness, age, weight, reproductive status and previous management sub grouping on social associations to test for homophily effects. Lastly, we evaluated whether social clustering was influenced by the stocking density of individuals in a field, and by weather parameters, through the use of two climatic indices, the Temperature-Humidity Index (THI) and the Wind Chill Index (WCI). Our results showed that the pairwise associations between ewes are not-random and highly heterogeneous, both in total time spent in contact and in contacts duration. There was no evidence that ewes were subdivided into social communities, and at individual level, they showed markedly differentiated social relationships, demonstrating preferences in social ties. However, the factors that influenced the preferred social interactions between individuals changed over time. In the first study period ewes tended to maintain the social bonds formed in previous management sub grouping, most likely due to a social familiarization resulting from repeated interactions with the same individuals. In the second study period similarity in age influenced the strength of associations among ewes. We found no significant influence of reproductive status, weight (as an indicator of body size) and genetic relatedness on proximity associations in either study period. Moreover, our results showed the tendency of the ewes to form social clusters varied in relation to animals’ density, and Wind Chill Index (WCI). The identification of conditions that modify the social behaviour of sheep is critically important in order to implement management and productivity strategies and our results highlight how flock social structure can change depending on environmental and social contexts.

Changing human-sensible temperature in Korea under a warmer monsoon climate over the last 100 years.

This study explores changes in means and extreme events of human-sensible temperature (HST), which is quantified by selective combination of Universal Apparent Temperature, Heat Index, and a new Wind Chill Index, in Korea for the last 100years (1919-2018) and illustrates the synoptic patterns of the East Asian monsoon system (EAMS) for extreme HST events. The time series analyses show that HST has increased much faster than near-surface air temperature (AT) in winter due to decrease in wind chill as well as to increase in AT. On the other hand, HST in summer, which is higher than AT on average because of high humidity in monsoon climate, has increased at a slow rate compared with those in other seasons. However, more extremely hot, long-lasting HST events have been observed in recent decades, as in 1994, 2013, 2016, and 2018, with shorter recurrent intervals. Greater increases of HST than AT are more distinct in the southern region under maritime subtropical climate than in the temperate climate zone in the north in all seasons. Composite maps for multiple high or low HST extreme events reveal that a dipole pressure anomaly pattern, rather than the intensity at the center of these air masses, is more closely related to the frequency of extreme HST events in Korea: A west high-east low pattern in winter formed by the expansion of the Siberian High accompanying an intense migratory low pressure system, and a south high-north low pattern formed by the westward intrusion of the Northwest Pacific subtropical high in summer after earlier terminations of summer rainy period (Changma). These indicate that monitoring of changing EAMS's characteristics is crucial to the mitigation of potential damages caused by unprecedented HST extreme events in the warmer twenty-first century.

Estimation of Travel Climate Comfort Degree in the Cross-border Region between China and Russia Based on GIS

The duration of travel climate comfort degree is an important factor that influences the length of the tourism season and the development of a tourism destination. In this study, we used the monthly average meteorological data for the last 10 years from 46 weather stations in Heilongjiang Province (China) and Primorsky Krai (Russia) to calculate the temperature–humidity index (THI) and wind chill index (WCI) based on ArcGIS software interpolation technology. We obtained the climate comfort charts of the study area with a grid size a 1 km2 grid size, and analyzed the spatial distribution of comfort for each month. The results show the following: 1) The THI and WCI of the cross-border region gradually decrease from south to north and from low altitude to high altitude. The annual comfortable climate period is longer when analyzed in terms of the WCI rather \than the THI. 2) The travel climate comfortable period of the study area shows significant regional difference and the length of the comfortable period in Heilongjiang Province is 4 to 5 months. Meanwhile, the period in Primorsky Krai decreases from south to north and the length of the comfortable period length in its southern region can reach 7 months. 3) The predominant length of the climate comfortable period in the cross-border area is 5 months per year, and it covers 46.6% of the total area, while areas that have a climate comfortable period of 2 months are the most limited, covering less than 0.3% of the area. The results provide a scientific basis for the utilization and development of a meteorological tourism resources and touring arrangements for tourists in the cross-border region between China and Russia.

Effects of housing condition, feeding style, and age on fattening performances, comfort, and some slaughterhouse characteristics in Eastern Anatolian Red bulls

It is crucial to bring domestic animal breeds to production and to produce meat based on sectoral structure. The objective of this study was to determine the effects of age, housing condition, and feeding style on fattening performance, comfort, and carcass characteristics of the Eastern Anatolian Red (EAR) bulls, a native breed which is suitable for adverse environmental conditions and marginal land as well as resistant to diseases. Twenty-five purebred EAR bulls (15 head of 2-year-olds and 10 head of 1-year-olds) were assigned randomly to 1 of 5 finishing programs after allocating by the age, feeding protocol, and environmental conditions. The groups were housed either individually in pens inside the barn or in paddocks outside the barn during the experimental period. The floor of the roofed paddock was cleaned and kept dry. The results indicated that there were statistically significant differences in daily live weight gain, total live weight gain (P < 0.05), and feed efficiency (P < 0.01) among the groups. The differences among the groups were also significant in terms of hot carcass, dressing, and pelvic fat (P < 0.01), as well as weights of noncarcass components (except head) (P < 0.01). The different values of the Wind Chill Index did not affect animal comfort adversely. It was clearly concluded that the EAR cattle can be a good fattening material if housing conditions and feeding style are appropriately designed.

Impact of Temperature Waves on the Health of Residents in Cities of the Northwestern Region of Russia

Local trends in meteorological indicators in the northwestern cities (St. Petersburg, Arkhangelsk, and Murmansk) were analyzed. Over the last two decades, the trends have demonstrated a nearly 0.9°С per decade increase in St. Petersburg and Murmansk and a more than 1.5°С per decade increase in Arkhangelsk. The health effects of cold waves on mortality were stronger than those of heat waves. Relative predictive powers of ambient air temperature and apparent temperature were compared in the study of the effects of heat waves on mortality. Ambient air temperature was more informative predictor. Wind chill index better than ambient air temperature explained variations in daily mortality during cold spells.

Physiological and Biochemical Responses of Banana ‘Prata-Anã’ Subjected to Hydrothermal Treatment

Objective: The objective of this study was to assess the effect of hydrothermal treatment applied to banana ‘Prata-Anã’ before refrigerated storage.&#x0D; Study Design: The employed experimental design was the completely randomized type (CRD) and composed of 4 repeats with 4 fruits, in a 5 x 4 +1 factorial scheme, with five storage days (days 1, 2, 3, 4 and 5) at 25°C after removal from the refrigerated chamber, four immersion temperatures and one control (fruits without hydrothermal treatment).&#x0D; Study Location and Duration: The experiment was conducted in the Post-Harvest Physiology Laboratory of the State University of Montes Claros between March and June 2017.&#x0D; Methodology: The bananas were harvested and separated into 4-fruit bouquets, which were immersed in water at 50, 52, 54 and 56°C for 2 minutes; fruits without hydrothermal treatment were used as control. Each bouquet was placed in polyolefin membrane packs that were then contained in boxes and stored in chambers at 10oC and RH of 80% for 25 days. After the 25 days, the fruits were taken out of the chamber and stored at 25oC. During the 25oC storage, physical and chemical analyses were performed.&#x0D; Results: On the day of removal from the refrigerated chamber, all bananas, regardless of treatment, presented a yellowish color. The temperature of 56oC resulted in greater fresh mass loss and higher solute extravasation values. Lower chilling index values and higher vitamin C values were found as the immersion temperature increased.&#x0D; Conclusion: The full ripening process of banana ‘Prata-Anã’ occurred after removal from the refrigerated chamber in all hydrothermal treatments and with lower chilling index values.

Effects of meteorological factor and air pollution on sudden sensorineural hearing loss using the health claims data in Busan, Republic of Korea.

Specific meteorological factors, including air pollution in the form of particulate matter (PM), affect the development of otologic disease and have adverse effects on the cardiovascular and respiratory systems. This study investigated relationships between the development of sudden sensorineural hearing loss(SSNHL) and meteorological factor with air pollution including PM. The daily patient number in 2015 admitted to the hospital with SSNHL were extracted from the Health Insurance Review and Assessment Service Bigdata in Busan. The meteorological factors and air pollution data of Busan area were obtained from meteorological stations in Busan. The relationship between the number of hospitalizations and the climatic factors was checked. SSNHL patient group showed more common in women, and the highest rates were observed in patients in their 50s. The daily mean patient numbers were 2.27. The number of SSNHL patients in spring was statistically significantly higher than that in summer. The mean daily PM10 and PM2.5 concentrations were 48.0 and 29.4 μg/m3, respectively. The mean wind speed, maximum wind speed and daily atmospheric pressure range was weakly positively associated with SSNHL patient number. There were weak negative correlations between maximum PM2.5 and SSNHL admissions. The mean temperature and wind chill index showed non-significantly negative relationships with SSNHL admissions. In Busan area, statistically significant weak relationships were detected between the daily numbers of patients admitted to the hospital with SSNHL and meteorological data, including PM level. Further investigation of these associations is required.

Estimation of lamb deaths within 5 days of birth associated with cold weather

In eight Australian Merino and crossbred sheep flocks, all lamb deaths were recorded, together with the corresponding weather before and after each case. Deaths on the day of birth were not strongly associated with a high chill index, but deaths in the following 3 days were significantly increased by a high chill index in the period between birth and the relevant day. Losses were greater for multiple-born lambs than singles under all conditions, but there was not a significant interaction of chill index with multiple births. A model is given for the risk of loss of lambs after birth, on the basis of birthweight, sex of the lamb, multiple birth and chill index for the ewe before birth and the lamb after birth. However, some of this information is not available until after the lamb is born, so a model is also given using only information available shortly before birth, namely, the expected chill index and whether pregnancy scanning has identified single or multiple lambs.

A technique to detect cell damage due to chilling injury for fruits and vegetables using Trypan blue and Evans blue

There are several methods to detect chilling injury symptom of produces such as the changes of electrolyte leakage (EL) or malondialdehyde (MDA) content. However, those methods detected whole injured tissue samples. They could not indicate the area of tissue or cell damage from chilling injury. Furthermore, there were several reports indicated that MDA content of some chilling injured tropical fruits were not concomitant with the EL and chilling injury index. In this study, a simple technique to detect cell damage caused by chilling injury was developed. Five tropical fruits and fruit vegetables which were susceptibility to chilling injury were kept at 4±1°C. Three samples from each fruit were collected daily and cross sectioned to 15 µm thick, then stained with either Trypan blue or Evans blue solutions. Stained tissues were examined under light microscope. The stained tissues were extracted and their optical densities (OD) were measured at 585 nm. The result showed that injured cells which lost cell membrane integrity were stained with Trypan blue and Evans blue, whereas live cells, of which their membrane is impermeable to the dyes, were excluded from staining. Thus these injured cells found mainly in the epidermal, sup-epidermal areas and were parenchyma cells. The ODs of crude extracts from Evans blue stained tissues were found to be related to the chilling injury index and MDA content of the chilling injured fruits. On the contrary, results from the control fruits kept at room temperature showed that the tissues were not stained with both Trypan blue and Evans blue. The OD of the solution from control tissues was not changed during study period. Moreover, Evans blue was more sensitive to detect cell damage compared to that of the Trypan blue. Therefore, this technique could be an alternative method to detect cell damage before chilling injury symptoms occur on the produce.

Application of extreme value distribution theory in the forecast of chilling return periods of Guangdong Province, China.

Chilling is the third weather disaster following flood and typhoon in Guangdong Province. Prediction of chilling return period is of practical significance for scientific reduction and protection of disaster. Four models, including Gumbel distribution, Weibull distribution, log-normal distribution and Peasron-III distribution, were applied, based on the chilling index, to fit the probability distribution of chilling extreme calculated by chilling accumulation for 86 weather stations of Guangdong Province from 1961 to 2015 (December to the following February). The optimal models were selected to calculate the chilling extreme value of return periods. Results showed that Pearson-III distribution was the optimal model for 77 out of the 86 weather stations. The log-normal distribution was optimal for eight weather stations and Gumbel distribution was optimal for only one station. Weibull distribution was not suitable for modeling extreme value of Guangdong Province. Different return periods of 10-, 25-, 50- and 100-year were predicted by optimal distribution models respectively, with a relative error less than 6%. Chilling extreme for years presented obviously latitude distribution feature, with more in north side and less in south side, which matched the distributions of the lowest temperature, average temperature and temperature dipping scale during chilling period. Our results are useful for guiding the chilling defense for relevant industries in Guangdong Province.

Salicylic acid maintained quality and enhanced shelf life of tomato ‘Samrudhi’ at refrigerated storage

Tomatoes are a frequently consumed fruit vegetable of the Solanaceae family and is rich in nutraceuticals. It faces rapid deterioration in edible quality during ambient storage, while refrigerated storage generally causes chilling injury. Therefore, an attempt was made with salicylic acid (SA), a safe phenolic having identified anti-ethylene effect, to evaluate its effect on shelf life and quality of tomatoes stored in refrigerated conditions. Fruits of tomato cultivar 'Samrudhi' at pink to light red stage were treated with different concentrations of salicylic acid (0.2-1.2 mM) along with control (water dipped) and were kept at 4-5°C with 65-80% relative humidity in four replications following completely randomized design. Results showed that SA treated fruits had better retention than control. At 21 days after storage (DAS), fruits kept as control showed maximum weight loss (14.65%) compared with the fruits treated with SA at 1.2 mM (5.88%). Fruits treated with SA at 1.2 mM had minimum chilling injury index (1.42), having high TSS (5.76 °Brix) and ascorbic acid (17.18 mg 100 g-1) retention. SA treated fruit in relatively higher concentration (0.8-1.2 mM), maintained fruit quality attributes with consistent intensification of carotenoids and lycopene even at 21 DAS. Shelf life was recorded maximum (33.25 days) in SA 1.2 mM treated fruits followed by SA 1.0 mM (30.25 days) compared with control (23.75 days).

BIOMETEOROLOGICAL CONDITIONS IN THE ARCTIC DURING THE FIRST INTERNATIONAL POLAR YEAR, 1882–1883

The article provides an initial description of the biometeorological conditions in the Arctic during the first International Polar Year (IPY 1) of 1882–1883. The study is based on hourly measurements taken from nine stations which represent most of the climatic regions in the Arctic. The diversity of biometeorological conditions was analysed in relation to the height above sea level, the distance from the sea and the character of the ground. The analysis made use of such biometeorological indices as wind chill index (WCI), predicted insulation of clothing (Iclp) and the cooling power of the air (H). A considerable spatial diversity of the biometeorological conditions was found during the period investigated. The least favourable thermal sensations occurred at the Sagastyr station, and the most favourable conditions were observed at Kapp Thordsen.