An Analysis of Land Surface Temperature Trends in the Central Himalayan Region Based on MODIS Products

Abstract

The scientific community has widely reported the impacts of climate change on the Central Himalaya. To qualify and quantify these effects, long-term land surface temperature observations in both the daytime and nighttime, acquired by the Moderate Resolution Imaging Spectroradiometer from 2000 to 2017, were used in this study to investigate the spatiotemporal variations and their changing mechanism. Two periodic parameters, the mean annual surface temperature (MAST) and the annual maximum temperature (MAXT), were derived based on an annual temperature cycle model to reduce the influences from the cloud cover and were used to analyze their trend during the period. The general thermal environment represented by the average MAST indicated a significant spatial distribution pattern along with the elevation gradient. Behind the clear differences in the daytime and nighttime temperatures at different physiographical regions, the trend test conducted with the Mann-Kendall (MK) method showed that most of the areas with significant changes showed an increasing trend, and the nighttime temperatures exhibited a more significant increasing trend than the daytime temperatures, for both the MAST and MAXT, according to the changing areas. The nighttime changing areas were more widely distributed (more than 28%) than the daytime changing areas (around 10%). The average change rates of the MAST and MAXT in the daytime are 0.102 °C/yr and 0.190 °C/yr, and they are generally faster than those in the nighttime (0.048 °C/yr and 0.091 °C/yr, respectively). The driving force analysis suggested that urban expansion, shifts in the courses of lowland rivers, and the retreat of both the snow and glacier cover presented strong effects on the local thermal environment, in addition to the climatic warming effect. Moreover, the strong topographic gradient greatly influenced the change rate and evidenced a significant elevation-dependent warming effect, especially for the nighttime LST. Generally, this study suggested that the nighttime temperature was more sensitive to climate change than the daytime temperature, and this general warming trend clearly observed in the central Himalayan region could have important influences on local geophysical, hydrological, and ecological processes.

Spatio-Temporal Analysis of Drought Variability Using CWSI in the Koshi River Basin (KRB)

“…Consequently, it is highly important to understand the drought pattern in order to assist decision makers in preparing appropriate strategies for the changing conditions therein. Unfortunately, few stations are established in mountainous areas of the Central Himalaya, and usually they lack long-term records [31]. In response to the abovementioned limitations, satellite remote sensing provides spatially contiguous high-accuracy and high-resolution information, particularly in remote mountainous areas [31]; thus, remote sensing constitutes an alternative approach to monitoring the dynamics of drought.…”

MODIS-based land surface temperature for climate variability and change research: the tale of a typical semi-arid to arid environment

“…Greenhouse gasses suppress cooling the earth surface by trapping terrestrial thermal radiation. Comparable results were reported in Nepal (Luintel et al, 2019;Zhao et al, 2019); the authors indicated that the mean annual LST and annual maximum LST in nighttime had mean change rates in the period 2000-2017 of about 0.048°C/year and 0.091°C/year, respectively. However, nighttime significant rates of increase obtained from the present study might be described as being faster than those obtained for Greece (Eleftheriou et al, 2018); the authors indicated that nighttime LST demonstrated increasing annual trends in the period 2000-2017 ranging from 4.6 × 10 −5 to 3.1 × 10 −3°C / year.…”

“…Accordingly, this study aims at determining the seasonalities and spatial and temporal rates of change of MODIS-based LST data and exploring whether these rates differ between daytime and nighttime in Jordana typical Middle Eastern semi-arid to arid country. Interestingly, the literature in this specific area of application is not at the desired level of ambitions and aspirations (Eleftheriou et al, 2018;Luintel, Weiqiang, Yaoming, Binbin, & Sunil, 2019;Mao et al, 2017;Sun, Wan, Imbery, Lotz, & King, 2015;Zhao et al, 2019), which makes this type of studies important in order to fill in this serious scientific gap. This study also aims at investigating whether the discerned daytime and nighttime spatial and temporal rates of change of MODIS-based LST in the study area are natural or anthropogenic.…”

Green Corridor Development as an Approach for Environmental Sustainability in Jordan

“…The green corridor should be away from highways by creating buffer zones along the path to protect the wildlife and provides safe places for visitors (Alexandre et al, 2010). According to Figure 14, designing buffer zones along the green corridor as open spaces provide a vital area for all services needed by humans, attractive places for tourism, increase air quality, protect the natural environment, and enhance awareness of humans to protect wildlife The higher elevations have been shown a sharp difference in temperature less than lower elevation (Zhao et al, 2019). Jordan weather is dry hot and dry in summer and cold in the winter.…”