近51年海南岛极端气温事件分析

ANALYSIS OF EXTREME TEMPERATURE EVENTS IN HAINAN ISLAND IN RECENT 51 YEARS

关键词:  极端气温事件  海南岛  极端阈值  变化趋势  海拔

Key words:  extreme temperature events  Hainan Island  extreme threshold  change trend  altitude

摘要:

利用1970—2020年海南岛18个气象站点逐日气温资料和数字高程数据，选取12个适用于研究区的极端气温指数，结合气候倾向率、相关分析等方法，分析了海南岛近51 a极端气温事件时空分布特征，并探讨极端气温事件与海拔、区域的关系。结果表明：近51 a海南岛极端气温冷事件(霜日日数、冷夜日数、冷昼日数、冷持续日数)呈减少趋势，极端气温暖事件(夏日日数、暖夜日数、暖昼日数、热持续日数)呈增加趋势，且增加幅度明显大于冷事件减少的幅度，极端低温阈值和高温阈值、日最高温极小值和极大值以及日最低温极小值和极大值均存在升温倾向，升温幅度在0.25～0.47 ℃/(10 a)之间；极端气温冷事件的变化趋势与海拔存在显著负相关关系，极端气温暖事件的变化趋势与海拔相关性较小；各极端气温指数在海南岛不同地区变化趋势的方向一致，但变化幅度的空间差异性较大，大部分极端气温指数在中部山区变化最明显，极端低温、高温阈值、霜日日数和夏日日数在南部地区变化幅度小于其他地区。

Abstract:

Using daily temperature data from 18 meteorological stations in Hainan Island from 1970 to 2020, we selected 12 extreme temperature indices applicable to the study area, and adopted methods such as climate trend rate and correlation analysis, to analyze the spatial and temporal distribution of extreme temperature events in Hainan Island in recent 51 years, and discuss the relationship between extreme temperature events and altitude as well as region. The results show that in the recent 51 years, the number of extreme temperature cold events (frost days, cold nights, cold days, and continuous cold days) decreased. By contrast, the number of extreme temperature warm events (summer days, warm nights, warm days, and continuous hot days) increased. The extreme low temperature threshold and high temperature threshold, the daily maximum high temperature minimum and maximum, and the daily minimum low temperature minimum and maximum all had a tendency of rising, and the rising range was 0.25～0.47 ℃/(10 a). There was a significant negative correlation between the variation trend of extreme temperature cold events and altitude, and the variation trend of extreme temperature warm events had little correlation with altitude. The trend of extreme temperature indices in different areas of Hainan Island was consistent, but spatial difference in the rate of change was large. Most of the extreme temperature indices varied significantly in the central mountainous region. The extremely low temperature, high-temperature threshold, frost days, and summer days varied less in the south of Hainan Island than those in other regions.