Study On The Representative Of The Water Temperature Observed By Coastal Observing Stations Of China

More and more oceanographic and meteorological data are needed in the coastal exploitation along with the expanding of oceanic exploitation of China. As sea temperature is one of the deciding factors in oceanography research, and is an important parameter in aquiculture and coastal project, the need of sea temperature data is increasing in the area of offing hydrology study and the exploitation of the oceanic resource in China.The sea surface temperature (SST) is one of the basic observing items in coastal observing stations. SST observed by coastal observing stations is extensively applied,because the data is long-term, continuous and is observed in shore. So, the analysis of the representative of water temperature observed by coastal observing stations is very necessary.The paper analyzes the spacial representative of the data in the bases of the need of the offing exploitation, the hydrological characteristic of China Sea and the representative of the water temperature observing site. It educe that the special representative must be elevated. The distributing of the data can only meets some need of the exploitation and oceanography study. There is no or less site in some sea bank, such as Yalu Rive estuary, Yellow River estuary, Laizhou Bay, some sea bank in Tangshan and Cangzhou erea, sea bank in the middle of Jiangsu province, sea bank in the northeast of Guangdong province and east coast of Zhanjiang, because the number of the site is so less and the distributing of the site is asymmetry. And the number of the insular site is much less than the need of the exploitation in the islands.The representative of the water temperature observing site is bad because of the influence of the position of the site, the limit of the nature conditions of the site and the influence of the oceanic exploitation. So the data from the site can't represent the water temperature characteristic of the sea area.The time representative is analyzed about the water temperature observing times, the influence to the data because of the different observing ways and the change of the observing site. The analysis of the water temperature data of Xiaomaidao station indicate that the difference of the daily mean water temperature calculated by continuous data and three data observed at 8, 14 and 20 o'clock is very little. The temperature difference is about 0.10℃, only a little time is more than 0.10℃.The difference of the monthly mean temperature is less than 0. 05℃.So only is observing water temperature at 8, 14 and 20 o'clock effect that the water temperature data is not continuous. But the influence of the statistical characteristic of the data is very little. In addition, the influence of the different observing ways and the change of the observing site effect that the water temperature is not continuous.After the introduction of the water temperature observing mechanism, the paper analyzes the vertical representative of the data by the contrast of the data observed by Xiaomaidao and Shidao station, Beihuangcheng and Xiaochangshan station and the data obtained from the map. The analysis indicates that the stations only observe sea surface temperature, so there is no long-term water temperature data of other water layers. And the water temperature observed by coastal observing stations is not the real sea surface temperature, but some not-surface layer's water temperature, because the temperature is observed in the tide well or the temperature & salinity well.After the analyzing of the water temperature data provided by Shidao, Xiaomaidao station and the hydrological station of Haiyang nuclear power station from 1997.3 to 1998.2, and the water temperature data provided by Shidao, Xiaomaidao station from 1991 to 2005, and that provided by Beihuangcheng, Xiaochangshan station from 1960 to 1977, this paper constructs the data with the data obtained from the map. It indicates that there is some comparability between the water temperatures observed by stations and the 10m layer water temperatures from the map. The relativity coefficient between the data provided by Shidao, Xiaomaidao station and the 10m layer water temperature data from the map is up to 0.9837; and the relativity coefficient between Beihuangcheng, Xiaochangshan station's data and the map's data is 0.9633.All of this proves that the water temperature observed by coastal observing stations is not the real sea surface temperature, and there is some comparability between this temperature and the 10m layer water temperature. In the end, the paper summarizes the problem of the water temperature observed by coastal observing stations and gives some suggestions. It suggests that add some water temperature observing sites , increase the construction of the coastal observing stations and make the water temperature auto-observation come true, to improve the representative of water temperature observed by coastal observing stations.