The role of snow and ice in the water cycle on the Tibetan Plateau

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In 1994, the final year of the project, intensive summer observations and wide area data and sample collections were made, besides continuing the monitoring observations.(1)Observations at Tanggula Mountain area were continued and the following data were obtained.(a)Data on the meteorological elements, glacier mass balance and ice temperature data, discharge data at 3 drainage areas were obtained for one full year. These are still continuing.(b)From May to November 1993, 10 Japanese members and 3 Chinese members, collaborated to measure elements needed for areal precipitation distribution, glacier mass balance, evaporation on frozen ground, areal characteristics of heat/water fluxes.(2)Following wide area data collections were made(a)Meteorological data and precipitation sample at various sites on the Plateau.(b)Satellite data (JERS1, MOS1, NOAA) for retrieving areal ground moisture and surface condition data.Following results were obtained from these observations and analysis.(1)As th … More e glaciers in these regions are cold, internal accumulation contributes much to the mass balance of the glacier.(2)The biological activity on the glacier is lower than the glaciers on the southern part of Tibet Plateau.(3)The active layer thickness of the frozen ground layer varies from 80 to 220cm among sites. The predominant determinant factor is the soil moisture content, rather than the soil texture. Evaporation is nearly doubled at thin active layer parts.(4)The drainage characteristics differ among three drainage areas (21 to 4538km2).(5)Precipitation in this area may reach 1000 mm per year which is much higher than the lower permanent stations.(6)Surface heat/water fluxes have altitude dependency in winter due to snow coverage, but depend on mainly on soil moisture in summer.(7)Three SAR images of the study area were obtained from satellite JERSI. Areal distribution of soil moisture may be able to be obtained from these data.(8)Characteristics of areal distribution of delta180 on Tibet Plateau, show some possibility of precipitation recycling in this area.As the intensive measurements were made at the last year of the three years study period, the final report will be published later in 1994. Less