ON THE THERMAL REGIME OF THE SURFACE AIR LAYER IN THE DEBED RIVER BASIN (ARMENIA)

2021 ◽  
Vol 1 (1) ◽  
pp. 31-44
Author(s):  
MARGARYAN V.G. ◽  
Keyword(s):  
River Basin ◽  
Air Temperature ◽  
Thermal Regime ◽  
Time Course ◽  
Temporal Distribution ◽  
Thermal Conditions ◽  
High Mountain ◽  
Air Temperatures ◽  
Using Data ◽  
Surface Air Layer

The features of the thermal regime of the surface air layer in the Debed river basin are considered. A statistical analysis of the average annual and average seasonal values of air temperature from 1964 to 2018 was carried out, two periods were identified, their time course was shown. The analysis was carried out using data from six meteorological stations representing the lowland, mountain and high-mountain climatic zones of the Debed river basin. A correlation was obtained between the absolute altitude and the monthly average values of air temperature for January and July, which can be used to assess the thermal conditions of unexplored or poorly studied territories and for cartography. The time course of average values of air temperatures for the seasonal period has been studied. Analysis of trend lines of temporal changes in air temperatures shows that in all situations on the territory of the basin as a whole, there is a tendency of temperature growth. Moreover, with a range of interannual fluctuations, a break in the course of temperatures in the early to mid 1990 is clearly visible, after which their significant increase began. It turned out that a significant increase in seasonal temperatures is observed especially over the period 1993-2018, which means that the annual warming after the mid 1990 occurred primarily due to summer and spring seasons. The regular dynamics indicates that in the studied area in terms of temperatures, a tendency of softening winters, a decrease in the water content of rivers, aridization of the climate. The results obtained can be used to assess the regularities of the spatial-temporal distribution of the temperature of the study area, to clarify the thermal balance, for the rational use of heat resources, as well as in the development of strategic programs for longterm analysis.

scholarly journals About the features of the time course of the average annual air temperature in the territory of the Debed river basin (Armenia)

2020 ◽  
Vol 223 ◽  
pp. 03009
Author(s):  
Varduhi Margaryan ◽  
Gennady Tsibulskii ◽  
Ksenia Raevich
Keyword(s):  
River Basin ◽  
Air Temperature ◽  
Time Course ◽  
Data Series ◽  
Observation Data ◽  
Air Temperatures ◽  
Daily Data ◽  
Long Term Observation ◽  
Surface Air Layer

The article examines the features of the time course of the average annual air temperature in the Debed river basin in Armenia. As a starting material, we used daily data of actual observations of the temperature of the surface air layer for a year in the Debed river basin. The study was carried out at 6 meteorological stations in the Debed river basin based on long-term observation data series from 1930 to the present (2018). Analysis of the trend lines of temporal changes in air temperatures shows that at all meteorological stations currently operating on the territory of the basin, there is mainly a tendency for an increase in temperatures of annual values.

ASSESSMENT OF THE FEATURES OF EXTREME LOW TEMPERATURES OF THE SURFACE AIR LAYER IN THE LAKE SEVAN BASIN (ARMENIA)

2020 ◽  
Vol 3 (1) ◽  
pp. 52-64
Author(s):  
V.J. MARGARYAN ◽  
Keyword(s):  
Low Temperatures ◽  
Temporal Distribution ◽  
Thermal Conditions ◽  
Absolute Minimum ◽  
Lake Sevan ◽  
Air Temperatures ◽  
Daily Data ◽  
The Absolute ◽  
Spatio Temporal ◽  
Surface Air Layer

The study is aimed to assess the patterns of spatio-temporal distribution of the extreme low temperatures of the Lake Sevan basin, their impact on the surrounding natural landscape landscape. As the source material, observations of daily data on the extremes of the minimum temperatures of the surface air layer at seven meteorological stations of the basin for the entire period (1891-2018). The methods used are mathematical-statistical, extrapolation, analytic, correlation, cartographic. A correlation was obtained between the average annual and annual absolute minimum values, as well as between the annual absolute minimum temperatures and the height of the area above sea level. The obtained relationships can be used to assess the thermal conditions of unexplored or little studied territories. As a result, a map of the spatial distribution of the annual absolute minimum temperatures of the surface air layer in the lake Sevan basin was compiled. Main conclusions. An analysis of the trend lines of temporary changes in the absolute minimum air temperatures shows that, at all weather stations currently operating in the basin, the absolute minimum temperatures tend to increase both monthly and annual...

scholarly journals The humid and thermal impact on distribution of Sea buckthorn fly (Rhagolethis batava Hering, 1958) in Mongolia

2021 ◽  
pp. 44-50
Author(s):  
Munkhtsetseg Baasan ◽  
Turbat Tumurbaatar ◽  
Dorjderem Balchin
Keyword(s):  
Geographical Distribution ◽  
River Basin ◽  
Air Temperature ◽  
Fruit Fly ◽  
Sea Buckthorn ◽  
Thermal Impact ◽  
Natural Zones ◽  
Average Annual Temperature ◽  
Maxent Modeling ◽  
Using Data

A total of 80 species in 1834 types of Tephritidae Newman (fruit flies) were recorded in the Mongolian-Russian comprehensive and joint expedition report, which was organized in 1967-1995. In the course of an itinerary survey conducted in 2019, we have recorded the dispersion of Rhagoletis batava at 223 natural (wild) and planted sea buckthorn points in 22 soums of Bayan-Ulgii, Uvs, Zavkhan, Khovd, Selenge and Govi-Altai aimags (provinces). Accordingly, we summarized the spread of sea buckthorn fruit fly relating mostly to territories that have dry and cooler climates, while some areas are humid and cold. Based on the dispersion points, we determined the current and future changes in the distribution of this species of flies, using the MaxEnt Modeling of geographical distribution. Thermal and humidity rates that affect the flies were estimated using data collected from 18 meteorological stations and sentinel posts. These points are located in different natural zones with an average annual air temperature fluctuating from -4.8 to 3.2°С. For example, in Tes soum of Uvs aimag, Bayantes soum of Zavkhan aimag and in Tes along the Tes river basin the average annual temperature is from -3.7 to - 4.8°С; in Baitag Kharuul of Bulgan soum of Khovd aimag, along the Bulgan river basin, the warmest temperature is 3.2°С, and in other soums it is -2.4 ... 1.8°С.

scholarly journals Estimation of sensible and latent heat based on measurements for non-typical large room

2019 ◽  
Vol 116 ◽  
pp. 00085
Author(s):  
Sylwia Szczęśniak ◽  
Juliusz Walaszczyk
Keyword(s):  
Latent Heat ◽  
Air Temperature ◽  
Historical Data ◽  
Operation Mode ◽  
Ventilation System ◽  
Thermal Conditions ◽  
Existing Building ◽  
Heating And Cooling ◽  
Air Temperatures ◽  
Heating And Cooling Load

The knowledge about dynamic changing heating and cooling load in existing building is essential for proper energy management. Whenever existing building is analyzed or ventilation system is going optimized, it’s essential to estimate temporary sensible and latent heat based on historical data. The basic conditions for heat calculations are quasi-stable thermal conditions. If supply air temperature significantly varies in short time, what happens very often, the calculations can give untrue results. The procedure described in this article improves usability of measured data affected by rapid supply air temperature changing. Therefore real sensible and latent heat can be calculated, what it is important for future optimization process. Specified, on the basis of varying supply and exhaust air temperatures, thermal loads range from -55.8 kW to 40.7 kW was substitute to more authentic range from -14.1 kW to 51.2 kW received from the conducted simulations. In addition, the data obtained from the simulation showed that latent heat gains were associated with the air temperature in the room, and not with the operation mode of the ventilation unit (day/night) as observed on the basis of historical data.

scholarly journals Trends in heat stress over Europe over the 20th century

2021 ◽  
Author(s):  
Joakim Kjellsson ◽  
Nils Niebaum ◽  
Robin Pilch Kedzierski
Keyword(s):  
Heat Stress ◽  
20Th Century ◽  
Heat Wave ◽  
Air Temperature ◽  
Heat Waves ◽  
Dew Point ◽  
Stress Index ◽  
Internal Climate Variability ◽  
Air Temperatures ◽  
Using Data

<p>We investigate how European heat waves and their associated heat stress on humans have changed over the 20th century. We find that the heat stress has increased, even in regions where heat waves have not become warmer. As heat stress increases over wide areas of Europe there is also an increase in the total population affected by the heat stress. </p><p>Heat waves pose a serious health risk to humans by reducing our ability to shed heat. We have studied the occurrence and intensity of heat waves as well as a heat stress index based on simplified wet-bulb globe temperature using data from ERA-20C reanalysis 1900-2010. Over the 110 years of data we find an overall warming of the air temperatures and dew point. The 98th percentile of both air temperature has increased by more than 1.5°C over large areas of Europe. </p><p>We find an overall increase in heat wave days per year as well as an increase of air temperature during heat waves over most of Europe. As such, many densely populated areas exhibit increased heat stress during heat waves. For example, the mean heat stress during heat wave days over Paris has increased by one level, from “alert” in 1900-1930 to “caution” in 1980-2010. The fraction of the population exposed to heat waves has increased by 10%/century in central Europe and 25%/century over the Mediterranean. </p><p>We find more heat waves during 1920 - 1950, which may be related to the positive phase of the Atlantic Multidecadal Variation (AMV). This suggests that the heat stress during European heat waves may also be influenced by internal climate variability, and large-ensemble model simulations may be used to disentangle the effects of natural variability and anthropogenic forcing.</p>

scholarly journals Trends of Changes of Maximum Air Temperature in Ukraine as an Impact Factor on Population Health

2020 ◽  
Keyword(s):  
Population Health ◽  
Air Temperature ◽  
Thermal Regime ◽  
Climate Changes ◽  
System Analysis ◽  
Global Climate ◽  
Maximum Temperature ◽  
Air Temperatures ◽  
Average Maximum ◽  
Maximum Air Temperature

Purpose. The aim of this research is detection of trends of changes (according to fact and scenario data) of extreme air temperature as a component of thermal regime in different regions of Ukraine because of global climate change. Methods. System analysis, statistical methods. Results. Time distribution of maximum air temperature regime characteristics based on results of observations on the stations located in different regions of Ukraine during certain available periods: Uzhgorod (1946-2018), Kharkiv (1936-2005), Оdessа (1894-2005), аnd also according to scenarios of low (RCP2.6), medium (RCP4.5) and high (RCP8.5) levels of greenhouse gases emissions. Meanwhile, air temperature ≥ 25°С was considered high (days with maximum temperature within 25,0-29,9°С are hot), ≥ 30°С was considered very high (days with such temperature are abnormaly hot). Trends of changes of extreme air temperatures were identified as a component of thermal regime in different regions of Ukraine within global climate changes. Dynamics of maximum air temperature and its characteristics in ХХ and beginning of ХХІ centuries were researched. Expected time changes of maximum air temperature and number of days with high temperature during 2021-2050 were analyzed by RCP2.6, RCP4.5 and RCP8.5 scenarios. There were identified the highest day air temperatures possible once in a century and also possibility of maximum day temperature more than 30°С by RCP4.5 scenario. Well-timed prediction of climate changes will help evaluate their impact on human and natural systems which will be useful for development and taking preventive measures towards minimization of negative influence of such changes. Conclusions. Processes of climate warming in Ukraine are activating. There was determined a strong trend on increasing of average maximum of air temperature in winter with speed 0.17-0,39 degrees centigrade/10 years. According to climatic norm this index mainly increased mostly (up to 3,3 degrees centigrade) in January in North-East of the country. In future such anomalies will grow. Determination of correlation between climate and health is the base for taking protective measures against perils for population health connected with climate.

scholarly journals Identifying the influence of dams and ponds on the thermal regime at regional scale: The case of Loire catchment

2020 ◽  
Author(s):  
Hanieh Seyedhashemi ◽  
Florentina Moatar ◽  
Jean-Philippe Vidal ◽  
Aurélien Beaufort ◽  
André Chandesris ◽  
...  
Keyword(s):  
Time Series ◽  
Air Temperature ◽  
Temperature Regime ◽  
Thermal Regime ◽  
Regional Scale ◽  
Stream Temperature ◽  
Annual Peak ◽  
Air Temperatures ◽  
Catchment Areas ◽  
Anthropogenic Structures

<p>Human activities and natural processes are the main drivers of the spatio-temporal variability of thermal regime. Despite a few local studies on the thermal regime variability, regional assessments are scarce in the scientific literature. However, regional assessments allow tracing systematic human-induced changes emerging from some types of anthropogenic structures like dams or ponds and identifying the locations of highly influenced reaches.</p><p>In the current study, we propose a framework to detect the influence of dams and ponds on stream temperature. We use observational data from 526 evenly distributed hourly stream temperature stations in the Loire River catchment, France (110,000 km<sup>2</sup>). The data consist of unbalanced time series of natural and altered thermal regimes that contain at least 80 summer days from 2000–2018. By comparing time series of observed stream temperature and air temperature, we define five indicators to distinguish different patterns of thermal regime. Three of them are based on weekly stream-air temperature linear regressions (slope; intercept; and coefficient of determination). The remaining two indicators compare monthly air and stream temperature regime: 1) the proportion of times stream temperature is greater than air temperature from March–October (“frequency”), and 2) the lag time between the annual peak in air temperature and annual peak in stream temperature (“shift”).</p><p>K-means clustering partitioned stations into three clusters: 1) pond-like, 2) dam-like 3) and natural, with 164, 37, and 316 stations, respectively. Supporting this cluster analysis, 93% of stations in pond-like cluster have upstream ponds, and 55% of stations in dam-like cluster have upstream large dams. Pond-like stations have the greatest slope between weekly stream and air temperatures (slope = 0.4) and have stream temperatures greater than air temperatures more frequently (68%) than other clusters. In contrast, dam-like stations have the lowest correlations between weekly stream and air temperatures (mean R<sup>2</sup>=0.3, compared to 0.7 for the other two clusters). Dam-like stations also exhibit the largest shifts in stream thermal regime relative to air temperature (mean shift = 30 days). Impounded runoff index (IRI), the ratio of reservoir volume to annual discharge, best explaines variability within the dam-like cluster. For pond-like stations, catchment areas and mean upstream ponded surface area best explain the within-cluster variability, particularly for the frequency indicator, although this relationship is sensitive to interannual air temperature regime.</p><p>These findings support modelers in quantifying the downstream impacts of different types of anthropogenic structures and managers in surveying and monitoring stream networks through identification of critical reaches.</p>

scholarly journals Effect of the duration of high air temperature on cow’s milking performance in moderate climate conditions

2018 ◽  
Vol 18 (1) ◽  
pp. 195-207 ◽  
Author(s):  
Piotr Herbut ◽  
Sabina Angrecka ◽  
Dorota Godyń
Keyword(s):  
Milk Yield ◽  
Air Temperature ◽  
Thermal Conditions ◽  
Climate Conditions ◽  
Air Temperatures ◽  
Holstein Friesian ◽  
Temperature Ranges ◽  
The Times ◽  
The Individual ◽  
Moderate Climate

Abstract The main aim of the presented investigation was to determine the effect of the air thermal conditions variability on cow’s milking performance in summer in a moderate climate. The analyses covered the summer months of 2012-2013 (June-September) and shorter, several-day periods characterized by the times of elevated or high air temperatures and by the declines and increases in milking performance. The research was conducted in a free stall barn for Holstein-Friesian cows. The study showed that the thermoneutral temperature for high yielding cows decreases gradually with the registered increasingly warmer summer periods. The decreases in milk yield already commence at an air temperature equal to 20°C and also depend on the dairy cattle sensitivity. July and August, with a high number of hot days, caused that in September the cows responded faster to a worsening of thermal conditions and the decline in milking performance happened almost simultaneously with the air temperature change, at milking yield recovery after the period of 3-4 d (r=-0.84, P<0.04). The percent duration in the individual temperature ranges which caused a decrease of milk yield was also determined. In June, and at the beginning of July, this was 90% of the time with temperatures above 20°C, and simultaneously 45% above 25°C occurred to milking performance decrease (r=-0.89, P<0.02). In September, this was only 30% of the time with temperatures above 20°C (r=-0.91, P<0.01).

scholarly journals New insights into the environmental drivers of the circumpolar ground thermal regime

2018 ◽  
Author(s):  
Olli Karjalainen ◽  
Miska Luoto ◽  
Juha Aalto ◽  
Jan Hjort
Keyword(s):  
Thermal Regime ◽  
Climatic Factors ◽  
Global Climate ◽  
Thermal Conditions ◽  
Cold Climate ◽  
The Arctic ◽  
Environmental Drivers ◽  
Active Layer Thickness ◽  
Thermal Dynamics ◽  
Air Temperatures

Abstract. The thermal dynamics of permafrost shape Earth surface systems and human activity in the Arctic and have implications to global climate. Improved understanding of the fine-scale variability in the circumpolar ground thermal regime is required to account for its sensitivity to changing climatic and geoecological conditions. Here, we statistically related circumpolar observations of mean annual ground temperature (MAGT) and active-layer thickness (ALT) to high-resolution (~1 km2) geospatial data to identify their key environmental drivers. The multivariate models fitted well to MAGT and ALT observations with average R2 values being ~0.94 and 0.78, respectively. Corresponding predictive performances in terms of root mean square error were ~1.31 °C and 87 cm. Freezing air temperatures were the main driver of MAGT in permafrost conditions while thawing temperatures dominated when permafrost was not present. ALT was most strongly related to solar radiation and precipitation with an important influence from soil properties. Our findings suggest that in addition to climatic factors, initial ground thermal conditions and local-scale topography-soil-driven variability need to be considered in order to realistically assess the impacts of climate change on cold-climate geoecosystems.

scholarly journals Multiple Indicators of Extreme Changes in Snow-Dominated Streamflow Regimes, Yakima River Basin Region, USA

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2608
Author(s):  
Anna M. Wagner ◽  
Katrina E. Bennett ◽  
Glen E. Liston ◽  
Christopher A. Hiemstra ◽  
Dan Cooley
Keyword(s):  
River Basin ◽  
Air Temperature ◽  
Snow Water Equivalent ◽  
Hydrological Cycle ◽  
Negative Impact ◽  
Clear Trend ◽  
Multiple Indicators ◽  
Air Temperatures ◽  
Yakima River ◽  
Streamflow Trends

Snow plays a major role in the hydrological cycle. Variations in snow duration and timing can have a negative impact on water resources. Excluding predicted changes in snowmelt rates and amounts could result in deleterious infrastructure, military mission, and asset impacts at military bases across the US. A change in snowpack can also lead to water shortages, which in turn can affect the availability of irrigation water. We performed trend analyses of air temperature, snow water equivalent (SWE) at 22 SNOTEL stations, and streamflow extremes for selected rivers in the snow-dependent and heavily irrigated Yakima River Basin (YRB) located in the Pacific Northwest US. There was a clear trend of increasing air temperature in this study area over a 30 year period (water years 1991–2020). All stations indicated an increase in average air temperatures for December (0.97 °C/decade) and January (1.12 °C/decade). There was also an upward trend at most stations in February (0.28 °C/decade). In December–February, the average air temperatures were 0.82 °C/decade. From these trends, we estimate that, by 2060, the average air temperatures for December–February at most (82%) stations will be above freezing. Furthermore, analysis of SWE from selected SNOTEL stations indicated a decreasing trend in historical SWE, and a shift to an earlier peak SWE was also assumed to be occurring due of the shorter snow duration. Decreasing trends in snow duration, rain-on-snow, and snowmelt runoff also resulted from snow modeling simulations of the YRB and the nearby area. We also observed a shift in the timing of snowmelt-driven peak streamflow, as well as a statistically significant increase in winter maximum streamflow and decrease in summer maximum and minimum streamflow trends by 2099. From the streamflow trends and complementary GEV analysis, we show that the YRB basin is a system in transition with earlier peak flows, lower snow-driven maximum streamflow, and higher rainfall-driven summer streamflow. This study highlights the importance of looking at changes in snow across multiple indicators to develop future infrastructure and planning tools to better adapt and mitigate changes in extreme events.

Sign in / Sign up

Export Citation Format

Share Document