Abstract:The background to the evolution of the high frequency sodar is reviewed. The principle of phased array is presented and so is the advantage of high frequency .sodar. Such kind of sodar is used for some special purposes. Being a remote sensing instrument, it is obviously with a promising future in an experimental mesoscale observing, network considering its lower cost as well as its satisfactory operations.

Abstract:In this paper, outgoing longwave radiation (OLR) data from 1975 to 1983 and ECMWF seven layers data from 1980 to 1983 are used to investigate the basic features of the tropical and the subtropical system in the steady rain processes over the middle-lower reaches of the Changjiang River in spring and their difference with those in the steadily clear processes. Furthermore,the anomalous circulation background over the tropics and the subtropics in the El-Nino years and its effect on the steady rain over the middle-lower reaches of the Changjiang River in the tran-sition seasons are discussed emphatically, and some significant facts are revealed.

Abstract:In this paper, the sensible heat flux and the latent heat flux have been calculated using the heat balance method and the information based on the dry bareland with windbreak and the moist winter wheat field. The results are. in the dry bareland with windbreak, 45% of the net radiation is dispersing as sensible heat flux,.35% as latent heat flux, and only 20% is stored in soil. The Bowen ratio is greater, usually within range -2<β<2. In the moist winter wheat field, almost all the net radiation contributes to the latent heat flux. But the sensible heat flux almostly appears negative in the whole day.The soil heat flux content is only 5% of the net radiation. The Bowen ratio usually within range - 1<β<1. In this paper, the errors of the Bowen ratio and the flux are also discussed.

Abstract:In this paper, the formulas calculating the incoming solar radiation through cloudy sky are given to connect Turner's (or Gordon's)approach and Smith's approach to Pasquill stability categories. It is also pointed out in the paper that the effective cloud amount defined as a half of the sum of total cloud cover and low-level cloud amount may simplify the cloud criteria and improve the accuracy in Turner's approach.