关键词: 西沙群岛, 涠洲岛, 气候变化, 近岸, 气温, 降水

Abstract: In this paper, the features of climate change and the difference between the islands and the coastal land are analyzed based on the basic meteorological data from the Xisha station and Weizhou Island station and their adjacent land stations from 1959 to 2014. The results show that: 1) in recent 56 years, the temperature changes in the Xisha Islands and Weizhou Island have shown an upward trend, the heating rate in the Xisha (0.19℃/10a) is greater than that in Weizhou Island (0.104℃/10a). Significant differences occurred in the last 10 years, the Xisha continued warming significantly (0.38 ℃/10a), while the temperature of Weizhou Island had a downward trend (-0.48℃/10a). As for the seasonal changes in the analysis, the spring of the islands was getting warmer while the winter getting colder. As compared with the surrounding land, the temperature of the islands was higher than that of the coastal land, but the warming rate less than that of the coastal land. 2) From analyzing the change of precipitation in recent 56 years, it is found that the precipitation, precipitation intensity and precipitation days of the islands were less than those of the coastal land. Controlled by the winter and summer monsoon conversion, Weizhou Island and the Xisha Islands showed a distinct dry season and a rainy season. Precipitation fluctuated greatly and its trend was insignificant in the last half century. With the decrease of precipitation days, precipitation intensity showed a significant growth trend. Contrasting the precipitation variation characteristics of the islands in nearly 10 years, we found that the Xisha station trended to be drier and drier in the dry season, and the precipitation in Weizhou Island and coastal land was increasing in both dry season and rainy season. 3) The average annual precipitation, the average precipitation in the rainy season and the average precipitation in the dry season in the islands were smaller than those in coastal land, but situation in the Xisha was opposite in November, December and January, that in Weizhou Island was opposite in January, July and August. The reason for this difference is that the land area in the Xisha is smaller and is more affected by oceanic air mass. Under the influence of South Asian monsoon, the seasonal characteristics were significant, it was humid and rainy in summer while dry and less rain in winter in Weizhou Island. The annual average precipitation and rainy season precipitation both in the Xisha and in coastal land were higher than those in Weizhou Island and its near shore area. During the dry season, the precipitation of the Xisha and the near shore area was lower than that of Weizhou Island and its near shore.

Key words: the Xisha Islands, Weizhou Island, climate change, near shore, air temperature, precipitation