Observed lead-lag relationships between Indian summer monsoon and some meteorological variables

摘要: Lagged relationships between the Indian summer monsoon and several climate variables are investigated. The examined gridded fields of snow cover (14 years), sea surface temperature (41 years) 500 hPa geopotential height north 20 °N (42 years). We also used series global air (108 Southern Oscillation index (112 Precipitation over all India during June–September a 112 year period as index. Emphasis is put on early precursors. In agreement with tendency for low frequency oscillation in ocean-atmosphere system, precursor patterns identified preceding monsoon. most important key regions seasons largest correlations selected corresponding to perform prediction. prediction shows however relatively moderate score mainly due not highly significant correlations. To improve predictions we filtered into their biennial (1.5–3.5 (3.5–7.5 modes. Correlations higher than those obtained without filtering especially mode. two modes out-of-phase before in-phase after. This phasing found except which It suggested that such may be formation could explain when concomitant or lagging Early based show improved scores actual