Temperature extremes over india and their relationship with el niño-southern oscillation

Abstract

The climate of a place represents the average weather in that place over more than thirty years' time period. While the weather can change in just a few hours, climate changes over longer time frames. Climate change is the variation in the Earth's global climate or in regional climates over time. It involves the variability or average state of the atmosphere over durations ranging from decades to millions of years. These changes can be caused by dynamic processes on the earth, external forces and human activities. Detection of change in climate against its variability is a key issue in climate research. Climate change is often expressed simply in terms of changes in the mean climate. However, regional climatic change in terms of extremes could have more significant socio-economic consequences than the changes in mean climate conditions as they may not show an appreciable change but may be characterized by a variety of extreme situations. There is a general agreement within the climate community that changes in the frequency as well as the intensity of extreme climate events would have profound impacts on natural and social systems. They can have serious and detrimental effects on human society and infrastructure as well as on ecosystems and wildlife. In general, the relationship between climate, extreme events and the extent of damage is extremely complex. The extreme events such as heat waves, floods, storms and dangerous avalanches have caused repeated concern in recent years. Our present knowledge of meteorological processes suggests that frequency and intensity of certain extreme events - for example, number of hot days and nights, heat waves, heavy precipitation and flood situations - will increase with the change in climate. However it remains uncertain whether or not to expect changes in some other extremes. The information based on current meteorological processes and model simulations must be taken into account in risk assessment, planning of precautionary measures and in development processes. © 2010 Springer Science+Business Media B.V.