Observational techniques on desert

为了发展沙漠边界层过程的观测技术，与中国科学家在甘肃黑河流域进行了联合研究。高祁连山冰川的水流到沙漠地区形成绿洲，并在该地区北部消失为沙漠。利用常规仪器和太阳能电池，在沙漠上建立了风、气温、湿度、辐射和土壤温度自动观测站。它工作得很好，只有一次突然失败了。A-D转换器在冰点以下的低温条件下出现零点偏移，需要进行校正。今年3月，8名日本科学家和3名中国科学家在这片沙漠上进行了一次实地实验。在沙漠的某个地方，地下水出现在距地面仅90厘米的地方。在这一点上，表面几厘米是完全干燥的，但在这一层之下，沙粒之间的空间（约36%）充满了大约20%的水。35-45厘米之间是一层冻沙。在某些地方和白天，表层的湿度很低，几乎为零，但在清晨，它会增加到80%左右。9月白天，中国考察组在戈壁沙漠上空观测到向下的湍流水汽通量。我们应该得出结论，沙漠地区的局势是非常复杂的。观测期间发生的沙尘暴气溶胶观测资料正在处理中。本研究成果将应用于“中日黑河地区空气-地面相互作用合作项目（HEIFE）”（1989-1993）。

In order develope observational techniques of boundary layer processes over desert Joint Research with Chinese scientists was made on Heihe River Basin in Gansu. Water from glacier on high Quilian mountains runs on the desert area forming oasisses and disappeares into desert in the north of this area. Automatic observing stations for wind, air temperature and humidity, radiation and soil temperature were established on the desert with normal instrumentations and solar battery. It worked well only one failier by thunder bolt. The A-D convertor showed zero point shift in low temperature conditions bellow freezing point and correction was required. A party of eight Japanese scientists with three Chinese scientists made a field experiment on the desert in March. At point on desert, the ground water appeared at only 90cm from the ground. At this point the surface few centi-meters are entirely dry but below that layer the space between sand particle (ca 36%) was filled with water for about 20%. And between 35-45cm was a layer or frozen sand. Humidity in the surface layer is very low almost zero point at some place and daytime but it increases up to about 80% in the early morning. Downward turbulent water vapor flux was observed by the Chinese group over Gobi desert in the daytime in September. We should conclude the situations over the desert area are very complexed. The aerosol observations of sand storms which happened during the observation are now under processing.The results of this research work will be applied to the Sino-Japan Cooperative Program on Air Surface Interaction in Heihe Area (HEIFE), 1989-1993.