Recent Trends in Rain Gauge Precipitation Measurements from the Tropical Pacific: Evidence for an Enhanced Hydrologic Cycle

Analysis of recently compiled tropical Pacific rain gauge measurements shows a trend toward increased precipitation in the central tropical Pacific during the period 1971–90. Previous studies of precipitation trends in this region have used satellite data and shipboard measurements, which have been demonstrated to contain a variety of known and unknown biases that could artificially produce a trend. Using rain gauge data, an independent and direct measure of the precipitation trends in the Pacific corroborates previous results based on satellite measurements, estimates of oceanic evaporation from shipboard meteorological observations, and results from numerical models. Furthermore, the result is consistent with suggestions that an enhancement of the tropical hydrologic cycle has been responsible for the increases in globally averaged tropospheric temperatures during the past two decades.