Trends in Sunshine Duration in Humid Climate of Northeast India: A Case Study

  • D. Jhajharia
  • P. K. Pandey
  • T. Tapang
  • S. Laji
  • K. Dahal
  • R. R. Choudhary
  • Rohitashw Kumar
Part of the Water Science and Technology Library book series (WSTL, volume 84)


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.


Trend 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.


  1. Barthakur M (2004) Weather and climate. In: Singh VP, Sharma N, Ojha CSP (eds) The Brahmaputra basin water resources. Kluwer Academic Publishers, pp 17–23Google Scholar
  2. Chattopadhyay S, Jhajharia D, Chattopadhyay G (2011) Univariate modeling of monthly maximum temperature time series over northeast India: neural network versus Yule-walker equation based approach. Meteorol Appl 18:70–82CrossRefGoogle Scholar
  3. Dev V, Dash AP (2007) Rainfall and malaria transmission in north-eastern India. Ann Trop Med Parasitol 101:457–459CrossRefGoogle Scholar
  4. Dinpashoh Y, Jhajharia D, Fakheri-Fard A, Singh VP, Kahya E (2011) Trends in reference evapotranspiration over Iran. J Hydrol 399:422–433Google Scholar
  5. Jhajharia D, Roy S, Ete G (2007) Climate and its variation: a case study of Agartala. J Soil Water Conserv 6(1):29–37Google Scholar
  6. Jhajharia D, Shrivastava SK, Sarkar D, Sarkar S (2009) Temporal characteristics of pan evaporation trends under the humid conditions of northeast India. Agric Forest Meteorol 149:763–770CrossRefGoogle Scholar
  7. Jhajharia D, Singh VP (2011) Trends in temperature, diurnal temperature range and sunshine duration in northeast India. Int J Climatol 31:1353–1367CrossRefGoogle Scholar
  8. Jhajharia D, Dinpashoh Y, Kahya E, Singh VP, Fakheri-Fard A (2012a) Trends in reference evapotranspiration in the humid region of northeast India. Hydrol Process. 26:421–435.
  9. Jhajharia D, Yadav BK, Maske S, Chattopadhyay S, Kar AK (2012b) Identification of trends in rainfall, rainy days and 24 hours maximum rainfall over sub-tropical Assam in northeast India. CR Geosci. 344:1–13.
  10. Kendall MG (1975) Rank correlation methods, 4th edn. Charles Griffin, LondonGoogle Scholar
  11. Kumar S, Merwade V, Kam J, Thurner K (2009) Streamflow trends in Indiana: effects of long term persistence, precipitation and subsurface drains. J Hydrol 374:171–183CrossRefGoogle Scholar
  12. Mann HB (1945) Non-parametric tests against trend. Econometrica 33:245–259CrossRefGoogle Scholar
  13. McVicar TR, Roderick ML, Donohue RJ, Li LT, Van Niel TG, Thomas A, Grieser J, Jhajharia D, Himri Y, Mahowald NM, Mescherskaya AV, Kruger AC, Rehman S, Dinpashoh Y (2012) Global review and synthesis of trends in observed terrestrial near-surface wind speeds: implications for evaporation. J Hydrol 416–417:182–205CrossRefGoogle Scholar
  14. Sen PK (1968) Estimates of the regression coefficients based on Kendall’s tau. J Am Stat Assoc 63:1379–1389CrossRefGoogle Scholar
  15. Stanhill G (1965) A comparison of four methods of estimating solar radiation. In: Eckardt FE (ed) Methodology of plant eco-physiology. Proceedings of the Montpellier symposium, Arid Zone Research, Vol XXV UNESCO, Paris, pp 55–61Google Scholar
  16. Stanhill G, Cohen S (2001) Global dimming: a review of the evidence for a widespread and significant reduction in global radiation with discussion of its probable causes and possible agricultural consequences. Agric Forest Meteorol 107:255–278CrossRefGoogle Scholar
  17. Theil H (1950) A rank invariant method of linear and polynomial regression analysis, Part 3. Netherlands Akademie van Wettenschappen, proceedings 53:1397–1412Google Scholar
  18. WMO (1997) Measurement of radiation guide to meteorological instruments and methods of observation, 6th edn. World Meteorological Organization, Geneva (Chapter 7)Google Scholar
  19. Yue S, Pilon P, Phinney B, Cavadias G (2002) The influence of autocorrelation on the ability to detect trend in hydrological series. Hydrol Process 16:1807–1829CrossRefGoogle Scholar

Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  • D. Jhajharia
    • 1
  • P. K. Pandey
    • 2
  • T. Tapang
    • 2
  • S. Laji
    • 2
  • K. Dahal
    • 2
  • R. R. Choudhary
    • 3
  • Rohitashw Kumar
    • 4
  1. 1.Department of Soil and Water Conservation EngineeringCollege of Agricultural Engineering and Post-Harvest TechnologyGangtokIndia
  2. 2.Department of Agricultural EngineeringNorth Eastern Regional Institute of Science and TechnologyItanagarIndia
  3. 3.Department of Electronics Instrumentation and Control EngineeringEngineering College BikanerBikanerIndia
  4. 4.Division of Agricultural EngineeringSher-e-Kashmir University of Agricultural Sciences and Technology of KashmirSrinagarIndia

Personalised recommendations