Stable isotope composition of precipitation over southeast Asia

作者：Luis Araguás‐Araguás, Klaus Froehlich, Kazimierz Różański · 发表于：Journal of Geophysical Research Atmospheres · 年份：1998 · DOI：10.1029/98jd02582 · 被引用次数：894 · 研究领域：Groundwater and Isotope Geochemistry、Geology and Paleoclimatology Research、Climate variability and models

Spatial and temporal variability of the stable isotope composition of precipitation in the southeast Asia and western Pacific region is discussed, with emphasis on the China territory, based on the database of the International Atomic Energy Agency/World Meteorological Organization Global Network “Isotopes in Precipitation” and the available information on the regional climatology and atmospheric circulation patterns. The meteorological and pluviometric regime of southeast Asia is controlled by five different air masses: (1) polar air mass originating in the Arctic, (2) continental air mass originating over central Asia, (3) tropical‐maritime air mass originating in the northern Pacific, (4) equatorial‐maritime air mass originating in the western equatorial Pacific, and (5) equatorial‐maritime air mass originating in the Indian Ocean. The relative importance of different air masses in the course of a given year is modulated by the monsoon activity and the seasonal displacement of the Intertropical Convergence Zone (ITCZ). Gradual rain‐out of moist, oceanic air masses moving inland, associated with monsoon circulation, constitutes a powerful mechanism capable of producing large isotopic depletions in rainfall, often completely overshadowing the dependence of δ 18 O and δ 2 H on temperature. For instance, precipitation at Lhasa station (Tibetan Plateau) during rainy period (June–September) is depleted in 18 O by more than 6‰ with respect to winter rainfall, despite of 10°C high...