Relationship between ENSO phases with Northwest India winter precipitation

摘要

Winter (December, January, February and March-DJFM) precipitation variability over Northwestern India is examined in association with large scale global forcing of El Ni?o Southern Oscillation (ENSO). During winter, Northwestern India receives precipitation in the form of snow, by eastward moving synoptic weather systems-western disturbances (WDs). An attempt is made to define relationship between wintertime large scale atmospheric fields with different phases of ENSO. A composite set of El Ni?o (10 years) and La Ni?a (8 years) is prepared to analyse role of large scale fields followed by ENSO response with wintertime precipitation over Northwestern India. Significant correlation between the two indicates increased (decreased) precipitation over Northwestern India during warm (cold) phase of ENSO. Higher geopotential height, with stronger southwesterly to northwesterly wind flow suggests more moisture flux from the Caspian and Arabian Sea. Empirical orthogonal function analysis also suggests instance of ENSO impact on Northwest India winter precipitation.