The Hydroclimatology of Kuwait: Explaining the Variability of Rainfall at Seasonal and Interannual Time Scales

摘要

This paper presents an analysis of the spatial, seasonal, and interannual variabilities of Kuwaiti rainfall. Based on an analysis of rain gauge, as well as satellite, datasets, it is estimated that about 110-190 mm of rainfall occurs annually in Kuwait, depending on the dataset sampled. The corresponding estimates for the standard deviations of the annual rainfall are about 40-70 mm. Discrepancies between values arise from the different techniques used in constructing each dataset. Moreover, the spatial distribution of annual rainfall features a gradual increase from the southwest to the northeast. A distinct rainy season occurs from November to April, with double peaks in January and March. In addition, the seasonal variability of rainfall is associated with shifts in patterns of midlatitude storm tracks, which propagate southward toward the Middle East during the winter and spring season. These trends are characterized using estimates of the spatial correlations of rainfall in Kuwait with the surrounding region. At the interannual time scale, significant correlation is found between the tropical El Nino-Southern Oscillation (ENSO) and annual rainfall anomalies. Similar weak correlations are found between midlatitude rainfall in Europe and rainfall in Kuwait. The weak connections observed with both tropical and midlatitude atmospheric systems are consistent with the fact that Kuwait is located in the transitional zone between the tropics and midlatitudes.