Trends in Sunshine Duration in Humid Climate of Northeast India: A Case Study
In the present study, trends in sunshine duration were investigated using the Mann–Kendall test in different timescales under the humid climatic conditions of Dibrugarh (Assam), Northeast India. Statistically significant decreasing trends were observed in the sunshine duration in the range of (−)0.61 to (−)1.28 h/decade over Dibrugarh in different timescales: annual; seasonal: winter; and monthly: January, June, and November during the past 28 years from 1981 to 2008. On the other hand, the significant increasing trend in sunshine duration was observed at the rate of (+)0.69 h/decade in the month of September over Dibrugarh. The observed decreasing trends in sunshine duration support the existence of the phenomenon of dimming over Northeast India, which may affect the water requirements in the region.
KeywordsTrend Mann–Kendall Sunshine duration Northeast India Global dimming
The authors thank the India Meteorological Department (Pune) for providing the bright sunshine duration data. The authors are grateful to the reviewer for critical comments that have helped in the improvement of the paper. Also, the authors acknowledge the financial support from the Director, NERIST, Nirjuli to attend the international conference.
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