Climatic variability at Gangtok and Tadong weather observatories in Sikkim, India, during 1961–2017

Abstract

The present study documents the long-term trends in the temperature and precipitation of a poorly represented region, the Sikkim, eastern Himalaya using the Mann–Kendall non-parametric test and the Sen’s slope estimator. Additionally, the normal distribution curves and Cusum charts have been used to identify the shifts in extreme events and to detect the points of change in the climatic data series for robust analysis. The minimum temperatures recorded a positive trend in Gangtok (0.036 ˚C year−1 from 1961 to 2017) as well as in Tadong (0.065 ˚C year−1 from 1981 to 2010) stations, while the maximum temperatures showed no trend in Tadong station from 1981 to 2010 which is consistent with the trend in Gangtok station for the overlapped period. However, it was negative for the overall assessed period (− 0.027 ˚C year−1 from 1961 to 2017) in Gangtok. The average temperatures in Gangtok recorded no trend whereas a positive trend (0.035 ˚C year−1 from 1981 to 2010) was observed at Tadong station. A similar positive trend in the average temperatures has been detected at Gangtok also for the overlapped period. Accelerated warming was noticed during the last two decades with an increase in the probability of extreme events of temperatures (minimum, maximum, average) at the higher end. Precipitation was found to be more variable across the observed period and suggested no trend in the study area.

Glacier changes in the Chhombo Chhu Watershed of the Tista basin between 1975 and 2018, the Sikkim Himalaya, India

“…It is now known that the climate of the Sikkim Himalaya is influenced by the triple system, primarily dominated by the Indian summer monsoon (ISM) that is the main source of precipitation (Racoviteanu et al, 2015), and additionally receives occasional precipitation through the northeast (winter) monsoon and hardly any from mid-latitude westerlies (Murari et al, 2014;Kumar et al, 2020). At the higher elevations, most of the precipitation is in the form of snow at any time of the year.…”

“…2a). The Mann-Kendall (MK) statistical method is employed to assess the climatic trends of mean monthly temperature and precipitation and their impact on glacier fluctuation in the study region (Kendall, 1975;Mann, 1945). A positive value of the Mann-Kendall Z statistic (Z MK ) indicates an increasing trend and vice versa (Cengiz et al, 2020).…”

“…Since 1901, a significant rise in daily maximum temperature of 1 • C in northeast India and a basin-wide warming trend of 0.6 • C in the Brahmaputra basin have been documented (Dash et al, 2007;Immerzeel, 2008). Moreover, the station-based meteorological data from the northeastern part of India and Sikkim indicate that the changes in rainfall and temperature patterns are seasonal and site-specific (Sreekesh and Debnath, 2016;Kumar et al, 2020). Future climate projection scenarios have reported a substantial rise in temperature and imbalances in precipitation regimes that may aggra-…”

Analysis of the Characteristics of Climate Change in the Ecologically Vulnerable Area of the Mu Us Dune Field under the Background of Global Warming

“…Climate change has always been a hot issue, focused on by scientific researchers around the world [1][2][3][4][5][6]. Deepening the understanding of climate change can provide a scientific basis for human beings to conduct reasonable practical activities [7].…”

Analysing Challenges and Strategies in Land Productivity in Sikkim Himalaya, India

“…Some of these challenges are very frequent, while others are less noticeable (Table 5). Due to changing climate, there is variation in rainfall patterns, as reported by the farmers, and it is correlated with the Indian Meteorological Department (IMD) data [23,24]. The significant impact of climate change on biodiversity, hydrology, agriculture and livelihood has been reported in Sikkim Himalaya [23,25,26].…”