Spatiotemporal Trends of Temperature Extremes in Bangladesh Under Changing Climate Using Multi-statistical Techniques

The rise in the frequency and magnitude of extreme temperature phenomena across the globe has led to the recurrent incidence of global climate hazards, which have had severe effects on socioeconomic development. The daily maximum and minimum temperature datasets of 27 sites in Bangladesh were used to detect spatiotemporal trends of temperature extreme over Bangladesh during 1980-2017 based on ten temperature extreme indices using multi-statistical modeling namely linear regression, Pearson correlation coefficient and factor analyses. Besides, mutation analyses based on the Mann-Kendall test, Sen’s slope estimator and Pettit test were employed to show the changing trend in extreme temperature. Results show that except for warmest days, the warm indices showed an increasing trend, mainly since the 2000s, while the growth rate was faster, and the response to global climate warming was sensitive. The cold indices demonstrated a reverse trend since the 2010s. Diurnal temperature range (DTR) and summer days (SU) increased faster, implying that the rising speed of daily max temperature was higher than of daily min-temperature in Bangladesh. The detrended fluctuation analysis (DFA) revealed a continuous increase in temperature extreme in the future except for cold days. The probability distribution functions (PDF) analysis revealed an evident variation of the curves in recent decades compared to the past three decades. Besides the warm night, DTR and SU primarily control the general warming trend of temperature extremes over Bangladesh during the study period. The mutation of the warm indices occurred before the cold index, indicating that the warm indices were more sensitive to global climate warming. The temperature extremes recognized in our research suggest that elevated warm temperature extremes due to global climate warming may have huge implications on the sustainable development of Bangladesh in the forthcoming period.

MERIDIONAL COMPONENTS OF ATMOSPHERIC CIRCULATION AND ARCTIC ICE COVER IN SUMMER

Statistical relationships are investigated between changes in total Arctic sea ice volume and variations in mean meridional velocities of air crossing the corresponding sections of the southern Arctic boundary during the summer months in 1979-2018. A consistent significant correlation between the ice volume and northerly wind speeds in the lower tropospheric layers is revealed for the Siberian sector. An increase in the analyzed correlation is found in 2012-2020 for all Northern Hemisphere sectors, except for the Atlantic one, which is supposedly due to the decrease in mean solar activity levels taking place against the intensifying global climate warming.

Geoinformation monitoring of the territory of Western Siberia

The article is devoted to the use of GIS technology for the control of swamp areas and environmental problems associated with the drainage of swamps in the industrial development of the West Siberian region, the main functions of swampy areas in the biosphere. The study examines the problems of drainage of swampy lands on the example of the territory of Western Siberia. Problems of the “greenhouse effect” and global climate warming, as well as problems of degradation and conservation of permafrost in the cryolithozone. It is established that swamps, as a natural mechanism for removing carbon dioxide from the atmosphere, are the only land geosystems with a constant flow of atmospheric carbon there. The problem associated with gas hydrates and the possibility of activation of microorganisms during the degradation of permafrost has been identified. To date, in the course of scientific experiments and studies based on the observation method, it has been established that natural gas hydrates are extremely sensitive to various technogenic factors.