中文摘要：

The characteristics of the atmospheric boundary layer height over the global ocean were studied based on the Constellation Observation System of Meteorology,Ionosphere and Climate(COSMIC) refractivity data from 2007 to2012.Results show that the height is much characteristic of seasonal,inter-annual and regional variation.Globally,the spatial distribution of the annual mean top height shows a symmetrical zonal structure,which is more zonal in the Southern Hemisphere than in the Northern Hemisphere.The boundary layer top is highest in the tropics and gradually decreases towards higher latitudes.The height is in a range of 3 to 3.5 km in the tropics,2 to 2.5 km in the subtropical regions,and 1 to 1.5 km or even lower in middle and high latitudes.The diurnal variation of the top height is not obvious,with the height varying from tens to hundreds of meters.Furthermore,it is different from region to region,some regions have the maximum height during 9:00 to 12:00,others at 15:00 to18:00.

英文摘要：

The characteristics of the atmospheric boundary layer height over the global ocean were studied based on the Constellation Observation System of Meteorology, Ionosphere and Climate （COSMIC） refractivity data from 2007 to 2012. Results show that the height is much characteristic of seasonal, inter-annual and regional variation. Globally, the spatial distribution of the annual mean top height shows a symmetrical zonal structure, which is more zonal in the Southern Hemisphere than in the Northern Hemisphere. The boundary layer top is highest in the tropics and gradually decreases towards higher latitudes. The height is in a range of 3 to 3.5 km in the tropics, 2 to 2.5 km in the subtropical regions, and 1 to 1.5 km or even lower in middle and high latitudes. The diurnal variation of the top height is not obvious, with the height varying from tens to hundreds of meters. Furthermore, it is different from region to region, some regions have the maximum height during 9：00 to 12：00, others at 15：00 to 18：00.