Average Summer Research Articles

Increase in household energy consumption due to ambient air pollution

In response to acute environmental stresses such as air pollution, households may resort to quick and convenient adaptation measures that increase energy use, amplifying the environmental impact and requiring additional adaptation. This cycle of energy-intensive adaptation has so far received little consideration by the broader energy community. Here, we analyse the response of Korean households to PM2.5 (ultrafine dust), based on real-time hourly smart meter data. We show that a 75 μg m–3 increase in PM2.5 concentration led to an 11.2% increase in electricity consumption, equivalent to the impact of a 3.5 °C increase in the average summer temperature. The magnitude of the energy-intensive adaptation correlated with households’ lifestyles and was higher on weekends and during daytime hours on both weekdays and weekends. The responses also reflected seasonal differences and had a U-shape relationship with temperature. We illustrate the importance of integrating the broader impacts of air pollution into policymaking to strike a proper balance between its mitigation and adaptation. The impact of energy consumption on air pollution in various forms has been studied extensively though less is known about how ambient air pollution affects energy use. Here, Eom et al. show how ambient air pollution increases domestic energy use in South Korea.

U.S. HOUSEHOLD PREFERENCES FOR CLIMATE AMENITIES: DEMOGRAPHIC ANALYSIS AND ROBUSTNESS TESTING

We estimate how climate amenities influence where households decide to reside in the United States with two main objectives in mind: (i) to produce estimates with sufficient demographic detail to inform demographic population projections for use in climate impact analysis; (ii) to study the robustness of estimates from the existing literature. With respect to the former goal, we find important differences in job-related migration motives by age group and in the overall propensity to migrate among households with children. With respect to the latter aim, our framework shares a common methodological approach with other, recent attempts to recover climate preferences, allowing us to explore the consequences of a number of key assumptions in a systematic manner. Consistent with the existing literature, we find relatively robust estimates of the impact of the frequency of extreme heat days on household location decisions. The impacts of other common measures of climate, including the frequency of extreme cold days, average summer and winter temperatures, annual precipitation, humidity and frequency of sunshine, do not show a strong enough signal in the data to be estimated with precision.

Transmission of West Nile and five other temperate mosquito-borne viruses peaks at temperatures between 23°C and 26°C.

The temperature-dependence of many important mosquito-borne diseases has never been quantified. These relationships are critical for understanding current distributions and predicting future shifts from climate change. We used trait-based models to characterize temperature-dependent transmission of 10 vector-pathogen pairs of mosquitoes (Culex pipiens, Cx. quinquefascsiatus, Cx. tarsalis, and others) and viruses (West Nile, Eastern and Western Equine Encephalitis, St. Louis Encephalitis, Sindbis, and Rift Valley Fever viruses), most with substantial transmission in temperate regions. Transmission is optimized at intermediate temperatures (23-26°C) and often has wider thermal breadths (due to cooler lower thermal limits) compared to pathogens with predominately tropical distributions (in previous studies). The incidence of human West Nile virus cases across US counties responded unimodally to average summer temperature and peaked at 24°C, matching model-predicted optima (24-25°C). Climate warming will likely shift transmission of these diseases, increasing it in cooler locations while decreasing it in warmer locations.

Linking tundra vegetation, snow, soil temperature, and permafrost

Abstract. Connections between vegetation and soil thermal dynamics are critical for estimating the vulnerability of permafrost to thaw with continued climate warming and vegetation changes. The interplay of complex biophysical processes results in a highly heterogeneous soil temperature distribution on small spatial scales. Moreover, the link between topsoil temperature and active layer thickness remains poorly constrained. Sixty-eight temperature loggers were installed at 1–3 cm depth to record the distribution of topsoil temperatures at the Trail Valley Creek study site in the northwestern Canadian Arctic. The measurements were distributed across six different vegetation types characteristic for this landscape. Two years of topsoil temperature data were analysed statistically to identify temporal and spatial characteristics and their relationship to vegetation, snow cover, and active layer thickness. The mean annual topsoil temperature varied between −3.7 and 0.1 ∘C within 0.5 km2. The observed variation can, to a large degree, be explained by variation in snow cover. Differences in snow depth are strongly related with vegetation type and show complex associations with late-summer thaw depth. While cold winter soil temperature is associated with deep active layers in the following summer for lichen and dwarf shrub tundra, we observed the opposite beneath tall shrubs and tussocks. In contrast to winter observations, summer topsoil temperature is similar below all vegetation types with an average summer topsoil temperature difference of less than 1 ∘C. Moreover, there is no significant relationship between summer soil temperature or cumulative positive degree days and active layer thickness. Altogether, our results demonstrate the high spatial variability of topsoil temperature and active layer thickness even within specific vegetation types. Given that vegetation type defines the direction of the relationship between topsoil temperature and active layer thickness in winter and summer, estimates of permafrost vulnerability based on remote sensing or model results will need to incorporate complex local feedback mechanisms of vegetation change and permafrost thaw.

Air pollution from wildfires and human health vulnerability in Alaskan communities under climate change

Alaskan wildfires are becoming more frequent and severe, but very little is known regarding exposure to wildfire smoke, a risk factor for respiratory and cardiovascular illnesses. We estimated long-term, present-day and future exposure to wildfire-related fine particulate matter (PM2.5) across Alaska for the general population and subpopulations to assess vulnerability using observed data for the present day (1997–2010), modelled estimates for the present day (1997–2001), and modelled estimates for the future (2047–2051). First, we assessed wildfire-PM2.5 exposure by estimating monthly-average wildfire-specific PM2.5 levels across 1997–2010 for 158 Alaskan census tracts, using atmospheric transport modelling based on observed area-burned data. Second, we estimated changes in future (2047–2051) wildfire-PM2.5 exposure compared to the present-day (1997–2001) by estimating the monthly-average wildfire-specific PM2.5 levels for 29 boroughs/census areas (county-equivalent areas), under the Intergovernmental Panel on Climate Change (IPCC) A1B scenario from an ensemble of 13 climate models. Subpopulation risks for present and future exposure levels were estimated by summing area-weighted exposure levels utilizing the 2000 Census and State of Alaska’s population projections. We assessed vulnerability by several subpopulation characteristics (e.g. race/ethnicity, urbanicity). Wildfire-PM2.5 exposure levels during 1997–2010 were highest in interior Alaska during July. Among subpopulations, average summer (June-August) exposure levels for urban dwellers and African-American/Blacks were highest at 9.1 µg m−3 and 10 µg m−3, respectively. Estimated wildfire-PM2.5 varied by Native American tribe, ranging from average summer levels of 2.4 µg m−3 to 13 µg m−3 for Tlingit-Haida and Alaskan Athabascan tribes, respectively. Estimates indicate that by the mid-21st century, under climate change, almost all of Alaska could be exposed to increases of 100% or more in levels of wildfire-specific PM2.5 levels. Exposure to wildfire-PM2.5 likely presents a substantial public health burden in the present day for Alaska communities, with different impacts by subpopulation. Under climate change, wildfire smoke could pose an even greater public health risks for most Alaskans.

Investigation of atmospheric ozone during summer and autumn in Guangdong Province with a lidar network

The overall ozone concentration in China has increased significantly in recent years, as has the atmospheric oxidization, and both of these changes are impacting human activities. Measurements based on differential absorption lidar (DIAL) were conducted from June to October 2019 in order to investigate the vertical distribution of ozone in Guangdong Province. The vertical and horizontal distributions of ozone in six different cities were systematically examined during the summer and autumn and analyzed the two different ozone characteristics (local pollution and regional transport). TrajStat was used to analyze the ozone transport directions and potential contributions of in the summer and autumn, and the following results were obtained. In the cities of Guangzhou and Jiangmen, the ozone concentrations climbed significantly higher in autumn than in summer, with the ozone concentration reaching a height of 1000 m in autumn and 600 m in summer. The diurnal variation of ozone in Yangjiang City in summer was not obvious, whereas in other cities, high levels of ozone were concentrated in the afternoon. The average summer ozone concentration at the Guangzhou site was the highest, approximately 92.57 μg/m3, whereas the average at the Dongguan site was the lowest. The average ozone concentration at the Guangzhou site in autumn was also the highest among the six cities, reaching 133.34 μg/m3. In terms of local pollution, the high-concentration ozone mainly occurred near the ground. The maximum ozone concentration was approximately 162.1 μg/m3 at about 350 m, and the ozone was evenly distributed above 1500 m. The external transport of ozone primarily occurred from 500 to 1100 m and above 1100 m. During summer, the southwest airflow trajectory was dominant, whereas northeast airflow predominated in autumn.

Assessing Heat Stress in Cattle Based on Analysis of Meteorological Factors

The objective of the survey is to assess the regional variation in climate change and the associated level of animals' susceptibility to heat-stress. The air temperature and humidity datasets measured for 1996–2015 at meteorological station nos. 27 595, 28 506, and 28 704 in the Republic of Tatarstan are used. The temperature-humidity index (THI) is estimated according to J. West (1994). The levels of heat stress are classified according to LPHSI (1990). The results show a relative uniformity of air temperature distribution in spring and autumn seasons (5.30 ± 0.21°C and 5.36 ± 0.18°C, respectively). The average 1996 winter temperature tended to be 0.41°C higher than that in winter 2010. Winter 2015 appeared warmest; the average temperature comprised –7.13°C. The average 1996 summer temperature comprised 18.48°C, which was 0.32°C lower than the long-term average. The average summer temperature for 2015 was 0.50°C lower than the long-term average. It was ascertained based on the calculated THI values that the cattle were free from heat stress in 64.02% of cases in the summer season, while the other animals were susceptible to heat stress at different levels in 35.98% of cases. In addition, some specimens were most susceptible to heat stress (24.62%). It is indicated that the temperature factor has a greater influence on the THI values (r = 0.995 (p < 0.01) and R2 = 0.9899).

Effect of self-curing admixture on concrete properties in hot climate conditions

Hot climates prevail in many regions of the globe. The average summer temperature of hot arid areas is in the range of 40–50 °C with temperatures exceeding these values under direct solar radiation. Curing concrete in these regions may be challenging due to limited availability of suitable water for curing and/or rapid loss of curing water by evaporation. For many years self-curing admixtures were recommended as an alternative to water curing, however, limited studies have been conducted on their performance in hot weather conditions. In this investigation, the effects of a hot climate on the fresh and hardened properties of self-curing (SC) concrete and normal conventional concrete (NC) in hot weather were studied. A water-soluble polymer self-curing agent, polyethylene glycol (PEG 400), was added to the SC mixes. The testing parameters were concrete dry materials (25 or 50 °C) and/or mix water temperatures (5, 20 or 35 °C) at the time of mixing. NC samples were continuously water cured at 25 or 50 °C, whereas the SC ones were air cured at the same temperatures. The tested properties were workability, compressive strength, splitting tensile strength, and flexural strength. It was found that SC outperformed NC under varying conditions. The results could not be simply attributed to the retention of mix water by the self-curing admixture. A more comprehensive explanation for the observations is proposed.

Time series assessment of the relationship between land surface temperature due to change in elevation: a case study from Hindukush-Himalayan Region (HKH)

Environmental studies that include studies related to climate change, change in biodiversity, and hydrology consider land surface temperature (LST) and near-surface air temperature as significant variables to contribute. In this context, we investigated the time series assessment of the relationship between LST and elevation over the two decades (1995–2017) using remotely sensed (Landsat 5, Landsat 7, Landsat 8, MODIS) and ground weather stations’ datasets. The study area that is Gilgit-Baltistan, northern province of Pakistan in Hindukush and Himalaya Region (HKH), was selected for quantitative analysis in this study as it has high significance in terms of climate change due to presence of very high and large number of mountains and difficult terrain heavily covered with snow and glaciers. To assess the LST, a linear regression model was developed to quantify the significance of key factors affecting it. Our research results show that there exists a strong negative linear relationship (with correlation coefficient of 0.61 on average) for all datasets (remotely sensed and in situ) between LST and elevation and it is consistent over the study period (1995–2017) for both seasons of winter and summer. Further, there is a difference of change in LST for different seasons (average winter and summer difference is 3.0 °C) and for different datasets (Landsat, MODIS, and weather stations’ dataset). There is a greater change in LST for change of elevation in 1000 m vertically as compared to change horizontally. Our results indicate that the change trend in LST from 1995 to 2007 is downward with minor variation, however, this trend changes into upward trend from 2007 to 2017. The comparison of results of remotely sensed and weather stations’ dataset shows that there is a consistency of change in temperature and LST due to change in elevation. However, there is a less difference in summers (0.76 °C) and large difference in winters, i.e., 3.94 °C.

Norwegian Atlantic Slope Current along the Lofoten Escarpment

Abstract. Observations from moored instruments are analyzed to describe the Norwegian Atlantic Slope Current at the Lofoten Escarpment (13∘ E, 69∘ N). The data set covers a 14-month period from June 2016 to September 2017 and resolves the core of the current from 200 to 650 m depth between the 650 and 1500 m isobaths. The along-isobath current, vertically averaged between 200 and 600 m depth, has an annual cycle amplitude of 0.1 m s−1, with the strongest currents in winter, and a temporal average of 0.15 m s−1. Higher-frequency variability is characterized by fluctuations that reach 0.8 m s−1, lasting for 1 to 2 weeks, and extend as deep as 600 m. In contrast to observations in Svinøy (2∘ E, 63∘ N), the slope current is not barotropic and varies strongly with depth (a shear of 0.05 to 0.1 m s−1 per 100 m in all seasons). Within the limitations of the data, the average volume transport of Atlantic Water is estimated at 2.0±0.8 Sv (1 Sv =106 m3 s−1), with summer and winter averages of 1.6 and 2.9 Sv, respectively. The largest transport is associated with the high temperature classes (&gt;7 ∘C) in all seasons, with the largest values of both transport and temperature in winter. Calculations of the barotropic and baroclinic conversion rates using the moorings are supplemented by results from a high-resolution numerical model. While the conversion from mean to eddy kinetic energy (e.g., barotropic instability) is likely negligible over the Lofoten Escarpment, the baroclinic conversion from mean potential energy into eddy kinetic energy (e.g., baroclinic instability) can be substantial, with volume-averaged values of (1–2)×10-4 W m−3.

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

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.

Remote sensing reveals Antarctic green snow algae as important terrestrial carbon sink

We present the first estimate of green snow algae community biomass and distribution along the Antarctic Peninsula. Sentinel 2 imagery supported by two field campaigns revealed 1679 snow algae blooms, seasonally covering 1.95 × 106 m2 and equating to 1.3 × 103 tonnes total dry biomass. Ecosystem range is limited to areas with average positive summer temperatures, and distribution strongly influenced by marine nutrient inputs, with 60% of blooms less than 5 km from a penguin colony. A warming Antarctica may lose a majority of the 62% of blooms occupying small, low-lying islands with no high ground for range expansion. However, bloom area and elevation were observed to increase at lower latitudes, suggesting that parallel expansion of bloom area on larger landmasses, close to bird or seal colonies, is likely. This increase is predicted to outweigh biomass lost from small islands, resulting in a net increase in snow algae extent and biomass as the Peninsula warms.

Urban mitigation and building adaptation to minimize the future cooling energy needs

In several areas of the world, the population concentrates along the coastal regions, benefitting from the sea breeze, with warmer inland areas. However, increasing population is driving urban sprawl in traditionally low-density areas, enhancing the synergies between global and local climate change. Here we show that local climate mitigation can reduce the impacts of climate change, with the analysis of a new development area in Sydney, 50 km from the coast. With meso-scale climate modelling, we computed that by 2050 the peak summer temperature will increase by 0.8 °C and the daily average summer temperature by 1.6 °C. Mitigation with cool materials, greenery, and irrigation will lower the peak and average daily temperatures respectively by 2.2 °C and 1.6 °C with respect to the unmitigated future climate scenario. Mitigation techniques when applied in the whole Sydney area yield to cooling energy needs reductions by 6.7–8.6 kWh/m2 (13.4–19.3%) for typical residential, office, and school buildings, with a negligible heating penalty, compared to an unmitigated future scenario. Combined adaptation and mitigation can reduce the future cooling energy needs by 31.3 kWh/m2 (70%), 29.3 kWh/m2 (57.3%), and 20.9 kWh/m2 (59.4%) for typical residential, office, and school building, respectively. Our study indicates that the consolidated and widely available mitigation technologies alone cannot counteract the energy impact of both global and local climate change. A structured system of interventions at building and urban scale is necessary while developing novel and higher efficiency mitigation technologies.

Do southern Appalachian Mountain summer stream temperatures respond to removal of understory rhododendron thickets?

AbstractDense understory thickets of the native evergreen shrub Rhododendron maximum expanded initially following elimination of American chestnut by the chestnut blight, and later in response to loss of the eastern hemlock due to hemlock woolly adelgid invasion. Rhododendron thickets often blanket streams and their riparian zones, creating cool, low‐light microclimates. To determine the effect of such understory thickets on summer stream temperatures, we removed riparian rhododendron understory on 300 m reaches of two southern Appalachian Mountain headwater streams, while leaving two 300 m reference reaches undisturbed. Overhead canopy was left intact in all four streams, but all streams were selected to have a significant component of dead or dying eastern hemlock in the overstory, creating time‐varying canopy gaps throughout the reach. We continuously monitored temperatures upstream, within and downstream of treatment and reference reaches. Temperatures were monitored in all four streams in the summer before treatments were imposed (2014), and for two summers following treatment (2015, 2016). Temperatures varied significantly across and within streams prior to treatment and across years for the reference streams. After rhododendron removal, increases in summer stream temperatures were observed at some locations within the treatment reaches, but these increases did not persist downstream and varied by watershed, sensor, and year. Significant increases in daily maxima in treatment reaches ranged from 0.9 to 2.6°C. Overhead canopy provided enough shade to prevent rhododendron removal from increasing summer temperatures to levels deleterious to native cold‐water fauna (average summer temperatures remained below 16°C), and local temperature effects were not persistent.

Has the West been won? A field survey and a species distribution model of Iberolacerta horvathi in the Alps

The Horvath’s rock lizard (Iberolacerta horvathi) is a rupicolous mountain species endemic of the eastern Alps and northern Dinaric range. The species has its known western limit of the distribution in the Veneto region of Italy. It is not known whether the species is really rare in Veneto or whether the area has been insufficiently surveyed. In addition, it is not known whether the westward distribution of the species is limited by a physiographic or by a climatic barrier. During the period 2016-2018, 118 sites were surveyed in the Veneto and Trentino-Alto Adige regions. Four new occurrences of Iberolacerta horvathi were discovered in Veneto that: 1) largely fill the gap between the westernmost known site and the closest site to the east; 2) extend further west the known distribution by 9 km. In addition the species was confirmed in three already known sites. A species distribution model was developed with the software MaxEnt, using 100 occurrences from Italy, Austria and Slovenia. The best model shows that the distribution is explained by the asperity of their habitat, the sedimentary bedrock, the aspect, the average temperature of the coldest quarter, the rainfall seasonality and the average summer rainfall. The last variable appears as the most likely responsible for the rarefaction of the species at its western limit. In addition, the species distribution model suggest that the Horvath’s rock lizard might be present in some additional mountain groups where it has so far not been found yet.

Deep Soil Water-Use Determines the Yield Benefit of Long-Cycle Wheat.

Wheat production in southern Australia is reliant on autumn (April-May) rainfall to germinate seeds and allow timely establishment. Reliance on autumn rainfall can be removed by sowing earlier than currently practiced and using late summer and early autumn rainfall to establish crops, but this requires slower developing cultivars to match life-cycle to seasonal conditions. While slow-developing wheat cultivars sown early in the sowing window (long-cycle), have in some cases increased yield in comparison to the more commonly grown fast-developing cultivars sown later (short-cycle), the yield response is variable between environments. In irrigated wheat in the sub-tropics, the variable response has been linked to ability to withstand water stress, but the mechanism behind this is unknown. We compared short- vs. long-cycle cultivars × time of sowing combinations over four seasons (2011, 2012, 2015, and 2016) at Temora, NSW, Australia. Two seasons (2011 and 2012) had above average summer fallow (December–March) rain, and two seasons had below average summer fallow rain (2015 and 2016). Initial plant available water in each season was 104, 91, 28, and 27 mm, respectively. Rainfall in the 30 days prior to flowering (approximating the critical period for yield determination) in each year was 8, 6, 14, and 190 mm, respectively. We only observed a yield benefit in long-cycle treatments in 2011 and 2012 seasons where there was (i) soil water stored at depth (ii) little rain during the critical period. The higher yield of long-cycle treatments could be attributed to greater deep soil water extraction (<1.0 m), dry-matter production and grain number. In 2015, there was little rain during the critical period, no water stored at depth and no difference between treatments. In 2016, high in-crop rainfall filled the soil profile, but high rainfall during the critical period removed crop reliance on deep water, and yields were equivalent. A simulation study extended our findings to demonstrate a median yield benefit in long-cycle treatments when the volume of starting soil water was increased. This work reveals environmental conditions that can be used to quantify the frequency of circumstances where long-cycle wheat will provide a yield advantage over current practice.

Thermal impacts of built and vegetated environments on local microclimates in an Urban University campus

Extreme urban temperatures pose a significant threat to human health, and are expected to worsen in a warming climate. While many heat island studies use land surface temperature to estimate exposure, air temperatures are more relevant to human health and comfort. The Tech Climate Network (TCN) was established to monitor 37 sites across the campus of the Georgia Institute of Technology and surrounding neighborhoods in various built and vegetated environments. This study seeks to answer: What is the distribution and intensity of the urban heat island on campus, and what impacts do surface-level land cover and surrounding tree canopy have on average summer air temperatures? Using multiple regression models, we examine the relationship between land cover parameters and minimum, maximum, and average air temperatures in the summer of 2017. We found that vegetated sites had lower temperatures than predominantly impervious environments, with differences in maximum temperatures up to 3.77 °C. UHI intensities were significantly correlated with tree canopy and landscaping. By characterizing the thermal properties of built and natural environments in such a diverse campus as Georgia Tech, this method allows for the estimation of local air temperatures without deploying a dense network of sensors.

Reconstruction of Climate and Landscapes of the Medieval Period on the Basis of Palynological Study of Paleosols Buried under Kurgans and Dendrochronological Data from Altai (South of Western Siberia)

Light loamy ordinary chernozems buried under two kurgans of a large Early Medieval necropolis Srostki-1 constructed in 890 ± 105…975 ± 85 AD (calibration by 1δ) were compared with the chernozem of the background territory in Biysk district of Altai. The analysis of pedological and 20 geochemical indices characterizing weathering, biological activity, and salt leaching demonstrated that the paleosols of the Medieval period in the phase before the construction of the kurgans had been formed in a somewhat drier climate compared to the modern conditions, and then the humidization of the paleoclimate began. According to palynological data, the considered period was characterized by a decrease in the area of pine stands, which could be due to colder winters. The areas of birch and riverine willow forests also decreased in comparison with the modern period because of the active cutting by humans of the Srostki ethnos. In the Medieval period, mesophytic rich forb communities occupied larger areas and predominated over dry-steppe communities. The growth of sedges was active on expanding marshes that appeared after drying of shallow water bodies upon the decrease in the water-protective role of forest vegetation. At the same time, a slight increase in the amount of pollen of xerophytic herbs, including representatives of Chenopodiaceae and Poaceae families and Artemisia genus took place. This could be related to the increased anthropogenic load, including soil disturbance upon the construction of 61 kurgans of the Srostki culture. Dendrochronological method was applied to reconstruct average summer temperatures over the past two thousand years. It was found that the heat supply of summer seasons in the Srostki period (8th–12th centuries AD) generally corresponded to that at present. However, the years of 850–870 and 930–950 AD were marked by summer cooling, and the years of 876–882 and 982 AD were marked by summer warming with average summer temperatures 1.5°C higher than the reference values of 1961–1990. The climatic variability of the Medieval period in different regions of the south of Western Siberia attests to the metachronous dynamics of the climate specified by the local conditions against the background of general climatic trends typical of Central Asia.

Results of the West Nile Fever Agent Monitoring in the Russian Federation in 2019 and the Forecast of Epidemic Situation Development in 2020

The trend towards an increase in the West Nile fever incidence among the population in the Russian Federation, recorded in the season of 2018, continued and led to a significant increase in the incidence in 2019 (the indicator was 2 times higher than the long-term average). The features of manifestations of the epidemiological process of WNF in 2019 were identified: early registration of cases of the disease, activation of natural and natural-anthropourgic foci in the Southern Federal District (90 % of the total incidence in the Russian Federation), an increase in the share of neuro-invasive forms, dominance of patients aged 50 and older in the structure of the incidence, late epidemic season ending. It was established that in the season of 2019, the lineage 2 of WNV circulated in the European part of Russia. In the Volgograd Region, simultaneous presence of the West Nile virus and Sindbis virus in mosquitoes Culex pipiens and Culex modestus was identified. It was shown that the most significant factors for predicting the epidemiological situation on West Nile fever in the Volgograd Region are the average seasonal summer air temperature and monthly average indicators of relative humidity in the spring and summer periods, and the average monthly air temperatures in the spring and summer in the Rostov Region. In the Astrakhan Region, a significant correlation dependence of the influence of the considered factors on the incidence of the population has not been established. The forecast of the development of epidemic situation in 2020 does not exclude a possible increase in the incidence in the territories of the European part of Russia, endemic for West Nile fever, and the occurrence of local outbreaks in individual constituent entities, if the complex of climatic conditions and social factors favorable for West Nile virus coincide.

Species vulnerability under climate change: Study of two sea urchins at their distribution margin

In order to develop powerful predictions on the impact of climate change on marine organisms, it is critical to understand how abiotic drivers such as temperature can directly and indirectly affect marine organisms. Here, we evaluated and compared the physiological vulnerability of the leading-edge populations of two species of sea urchins Loxechinus albus and Pseudechinus magellanicus in response to predicted ocean warming and food limitation. After exposing sea urchins to a 60-day experimental period to contrasting temperature (1 °C, 7 °C and 14 °C corresponding respectively to the actual average summer temperature in Antarctica, the control treatment temperature and the predicted future temperature in the Strait of Magellan) and diet levels (ad libitum or food limitation), sea urchin stress tolerance was assessed. Sea urchins' physiology was measured at the organismal and sub-cellular level by studying the organisms energy balance (behavior, growth, gonad index, ingestion rate, O2 uptake, energy reserves) and the expression of genes associated with aerobic metabolism. Our results showed that at their distribution edge, and despite their distinct geographical repartition, both species might be resilient to ocean warming. However, the combination of ocean warming and food limitation reduced the stress tolerance of sea urchins. In a warming ocean, another strategy could be to migrate toward the pole to a cooler environment but incubation at 1 °C resulted in a diminution of both species' aerobic scope. Overall, if these engineer species are unable to acclimate to food limitation under future climate, population fitness could be affected with ecological and economic consequences.