Based on the local climate zoning theory and the observation data of hourly temperature of 22 automatic weather stations from 2012 to 2021, K-means clustering algorithm was used to analyze the daily, monthly, seasonal...Based on the local climate zoning theory and the observation data of hourly temperature of 22 automatic weather stations from 2012 to 2021, K-means clustering algorithm was used to analyze the daily, monthly, seasonal, annual and spatial variation characteristics of urban heat island effect in Weihai City in the past 10 years. The results showed that in recent 10 years, the average urban heat island intensity was 1.24 ℃, showing a gradual weakening trend of -0.169 3 ℃/10 a;the summer average heat island intensity was 0.86 ℃, showing a gradual weakening trend of -0.047 5 ℃/10 a. The heat island intensity had obvious diurnal variation characteristics, that is, "it was weak in the day and strong at night". In terms of seasonal variation, heat island effect was the weakest in summer, stronger in spring and autumn, and the strongest in winter. The diurnal, seasonal and annual changes of heat island intensity showed a reverse trend to those of temperature. The high-value area of urban heat island was highly consistent with human residential activity areas and industrial and commercial intensive areas, and the extension trend of heat island intensity was the same as the direction of urban development and construction. The "cold island phenomenon" in some offshore areas was related to the geographical location, terrain and the southeast monsoon trend in summer. The adverse effects of urban heat island effect can be reduced by optimizing the types and distribution of vegetation communities, rationally planning and constructing urban water body, promoting green building materials and adjusting shape design, etc.展开更多
On 10 December 2017,a Chinese research vessel R/V Xuelong encountered an extensive area of landfast ice offshore Inexpressible Island(Antarctica)near the location where the fifth Chinese Antarctic research station is ...On 10 December 2017,a Chinese research vessel R/V Xuelong encountered an extensive area of landfast ice offshore Inexpressible Island(Antarctica)near the location where the fifth Chinese Antarctic research station is to be built.Using multi-source satellite images and weather data,we analyzed the ice conditions during the event season and reconstructed the development of landfast ice.Two stages in late September and early October were identified as contributing to the final ice extent.These two events are highly related to local-and large-scale weather conditions.Satellite images from 2003 to 2017 showed that four in fifteen years experienced severe landfast ice conditions,suggesting that it is not a rare phenomenon.展开更多
基金Supported by the Science and Technology Research Project of Shandong Meteorological Bureau(2022SDQN17).
文摘Based on the local climate zoning theory and the observation data of hourly temperature of 22 automatic weather stations from 2012 to 2021, K-means clustering algorithm was used to analyze the daily, monthly, seasonal, annual and spatial variation characteristics of urban heat island effect in Weihai City in the past 10 years. The results showed that in recent 10 years, the average urban heat island intensity was 1.24 ℃, showing a gradual weakening trend of -0.169 3 ℃/10 a;the summer average heat island intensity was 0.86 ℃, showing a gradual weakening trend of -0.047 5 ℃/10 a. The heat island intensity had obvious diurnal variation characteristics, that is, "it was weak in the day and strong at night". In terms of seasonal variation, heat island effect was the weakest in summer, stronger in spring and autumn, and the strongest in winter. The diurnal, seasonal and annual changes of heat island intensity showed a reverse trend to those of temperature. The high-value area of urban heat island was highly consistent with human residential activity areas and industrial and commercial intensive areas, and the extension trend of heat island intensity was the same as the direction of urban development and construction. The "cold island phenomenon" in some offshore areas was related to the geographical location, terrain and the southeast monsoon trend in summer. The adverse effects of urban heat island effect can be reduced by optimizing the types and distribution of vegetation communities, rationally planning and constructing urban water body, promoting green building materials and adjusting shape design, etc.
基金supported by the National Natural Science Foundation of China (Grant nos. 41676176 and 41830536)the Open Fund of State Key Laboratory of Remote Sensing Science (Grant no. OFSLRSS201926)
文摘On 10 December 2017,a Chinese research vessel R/V Xuelong encountered an extensive area of landfast ice offshore Inexpressible Island(Antarctica)near the location where the fifth Chinese Antarctic research station is to be built.Using multi-source satellite images and weather data,we analyzed the ice conditions during the event season and reconstructed the development of landfast ice.Two stages in late September and early October were identified as contributing to the final ice extent.These two events are highly related to local-and large-scale weather conditions.Satellite images from 2003 to 2017 showed that four in fifteen years experienced severe landfast ice conditions,suggesting that it is not a rare phenomenon.