Unstable ENSO relationship with Indian regional rainfall

摘要

In earlier years, El Ninos had a strong association with droughts in India. However, in recent years, this relationship seems to have weakened, and even the strong event of 1997-1998 did not produce the expected effects. In the 133-year data, only about 60% of the El Nino and La Nina are effective, and the magnitudes of the anomalies are not in good correlations with the strength of the ENSO. This weakening of ENSO effects in recent years is known to meteorologists. The Indian Meteorological Department (IMD) scientists have formulated prediction schemes, but these are not fully satisfactory. The public and the press are still swayed only by possible El Nino effects, as happened in 2005 when Pacific warming Occurred in February. The meteorologists had to assure the press that this was a case of an 'aborted El Nino', with quiet conditions expected to return by the end of 2005. Considering the experience of the 1997-1998 El Nino, when a strong El Nino developed suddenly, a prediction of a quiet 2005 can be hazardous. More importantly, even if an El Nino develops in the next few months, the press should be told that the chance of strong El Nino effects (droughts) is only about 60%, and these too may be very different in different regions of India. Copyright (C) 2005 Royal Meteorological Society.