Advertisement

Role of vorticity advection and thermal advection in the development of western disturbance during North Indian winter

  • N. Vinod Sankar
  • C. A. BabuEmail author
Original Paper
  • 13 Downloads

Abstract

Western disturbance is defined as a low on the surface or an upper air cyclonic circulation in the westerly wind regime seen over northern parts of the Indian subcontinent. These systems originate over Mediterranean Sea, Caspian Sea or Black Sea and move eastward across north India. The precipitation over the northern parts of India during the winter months of January and February could be attributed to western disturbance. Ten western disturbances which resulted in fairly widespread, moderate to heavy rainfall over north India have been studied. The data used were obtained from NCEP and IMD. The systems were traced from West Asia to Western Himalayas. It is observed that Western disturbance causes 3–4 days of scattered light to moderate precipitation and one or 2 days of moderate to heavy precipitation. The specific humidity reaches a maximum value of greater than 10 g kg−1 at 1000 hPa between 0600 and 1200 UTC, a day prior or on the day of heavy rainfall. Positive vorticity advection takes place as a WD approaches the Indian region. The maximum value of vorticity advection reaches in the range of 1–2 × 10−7 s−1 between 500 and 250 hPa. A strong differential vorticity advection is observed between lower and middle troposphere on the day of most intense and widespread precipitation. It is also observed that the updraught maximum coincides with the differential vorticity advection maximum. When the WD is active, warm and moist air advection takes place over north India, which increases with height, reaching its maximum values of 7–12 × 10−4 K s−1 at levels between 300 and 200 hPa.

Notes

Acknowledgements

The authors wish to thank the India Meteorological Department for making the rainfall data available. Sincere gratitude is also extended to NCEP/NCAR for providing the reanalysis data. We also wish to acknowledge the Centre for Ocean–Land–Atmosphere Studies for making the GrADS software available online, which has been extensively utilised in this study.

References

  1. Azad R, Sorteberg A (2014) Vorticity budgets of North Atlantic winter extratropical cyclones life cycles in MERRA reanalysis Part I: development phase. J Atmos Sci 71:3109–3128CrossRefGoogle Scholar
  2. Bluestein HB (1993) Synoptic-dynamic meteorology, vol II. Observation and theory of weather systemsGoogle Scholar
  3. Carroll EB (1995) Practical subjective application of the omega equation and sutcliffe development theory. Meteorol Appl 2:71–81CrossRefGoogle Scholar
  4. Carroll EB (1997) Use of dynamical concepts in weather forecasting. Meteorol Appl 4:345–352CrossRefGoogle Scholar
  5. Carroll EB (2003) Thermal advection, vorticity advection and potential vorticity advectionin extra-tropical, synoptic-scale development. Meteorol Appl 10:281–292CrossRefGoogle Scholar
  6. Chand R, Singh C (2015) Movement of Western Disturbance and associated cloud convection. J Ind Geophys Union 19(1):62–70Google Scholar
  7. Dimri AP (2004) Impact of horizontal model resolution and orography on simulation of Western Disturbances and its associated precipitation. Meteorol Appl 11:115–127CrossRefGoogle Scholar
  8. Dimri AP (2007) The transport of momentum, sensible heat, potential energy and moisture over western Himalayas during winter season. Theor Appl Climatol 90(1–2):49–63CrossRefGoogle Scholar
  9. Ganju A, Dimri AP (2004) Prevention and Mitigation of avalanche disasters in western Himalayan region. Nat Hazards 31:357–371CrossRefGoogle Scholar
  10. Glossary of terminologies and definitions, India Met Dept. https://imd.gov.in/section/nhac/termglossary.pdf
  11. Hatwar HR, Yadav BP, Rao YVR (2005) Prediction of Western Disturbance and associated weather over western Himalayas. Curr Sci 88(6):913–920Google Scholar
  12. Kumar N, Mohapatra M, Jaswal AK (2017) Meteorological Features associated with unprecedented precipitation over India during 1st week of March 2015. J Earth Syst Sci 126:62CrossRefGoogle Scholar
  13. Kuwano-Yoshida A, Enomito T (2013) Predictability of explosive cyclogenesis overnorth-western Pacific region using ensemble analysis. Mon Weather Rev 141:3769–3785CrossRefGoogle Scholar
  14. Lang TJ, Barros AP (2004) Winter Storms in western Himalayas. J Meteorol Soc Jpn 82(3):829–844CrossRefGoogle Scholar
  15. Laskar SI, Bhan SC (2015) Diagnosis and numerical simulation of WD andassociated rainfall over India during March 2015. Int J Earth Atmos Sci 12(4):98–126Google Scholar
  16. Liu Y, Wang D, Liang Z, Liu C (2016) The structure and development of an extratropical cyclone over north-eastern Asia. SOLA 12:253–258CrossRefGoogle Scholar
  17. Martin JE (2006) Mid—latitude atmospheric dynamics 413 (a first course). Chap 1(4):17–19Google Scholar
  18. Mohanty UC, Madan OP, Rao PLS, Raju PVS (1998) Meteorological field associated with Western Disturbances in relation to glacier basins of western Himalayas during the winter season. Tech. Rep, Centre for Atmospheric Science, DelhiGoogle Scholar
  19. Morris WE, Phillip JS (2001) Cyclolysis: a diagnosis of two extratropical cyclones. Mon Weather Rev 129:2714–2729CrossRefGoogle Scholar
  20. Petterssen S (2013) Introduction to meteorology. Books.google.comGoogle Scholar
  21. Plant RS, Craig GC, Gray SL (2003) On a threefold classification of cyclogenesis. QJR Meteorol Soc 129:2989–3012CrossRefGoogle Scholar
  22. Rajeevan M, Bhate J, Kale JD, Lal B (2005) Development of a high resolution daily gridded rainfall data for Indian region: a Met Monograph Climatology N0 22/2005.National Climate Centre, India Meteorological DepartmentGoogle Scholar
  23. Raju PVS, Bhatla R, Mohanty UC (2011) A study on certain aspects of kinetic energy associated with western disturbances over northwest India. Atmosfera 24(4):375–384Google Scholar
  24. Rao YP, Srinivasan V (1969), Discussion of typical synoptic weather situation: Western Disturbances and their associated features, India Meteorological Department: Forecasting Manual Part IIIGoogle Scholar
  25. Sharma RV, Subramaniam DV (1983) The western disturbance of 22 december 1980: a case study. Mausam 34(1):117–120Google Scholar

Copyright information

© Springer-Verlag GmbH Austria, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Atmospheric SciencesCochin University of Science and TechnologyKochiIndia

Personalised recommendations