Geoscience Reference
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Fig. 12 Correlation between ISMR and mean outgoing longwave radiation (OLR) of July and August using
data of 1979-2009 showing the two poles of convection (monsoon heat source). In drought monsoon years,
positive convection anomalies (negative OLR anomalies) are over west Pacific Ocean
Fig. 13 Correlation between ISMR and 200 hPa meridional wind of June to September showing the Asia-
Pacific wave (wave number 6). In drought monsoons, this wave has a trough over northwest India and
another trough close to Japanese Islands
years (10-15 consecutive years) as in the Sahelian drought incidences. Such an event is
described in the Bible when Egypt was ruled by Pharaohs, one of whom made biblical
Joseph governor of Egypt to manage the food problems in a 7-year-long drought episode.
The food managers of India have to store food grain to meet the needs of one or at most
two consecutive drought years only.
During the DRY epoch 1961-1990 reanalysed wind data showed that subtropical
westerlies of the upper troposphere moved to lower latitudes over south Asia as a wave
number-3 trough—see Fig.
11
. During this epoch SST, monsoon convective heat source
