To understand how temperature varies in urban Shanghai under the background of global climate change and how it is affected by urbanization, the Shanghai temperature responses to global warming were analyzed, and then...To understand how temperature varies in urban Shanghai under the background of global climate change and how it is affected by urbanization, the Shanghai temperature responses to global warming were analyzed, and then the temperature trends of urban and suburb stations under different climatic backgrounds were obtained. The urbanization effects on temperature were studied by comparing urban stations to suburb stations, the relationship between urbanization variables and temperature components were obtained, and observation data of surface and high level were combined to assess the contribution of urbanization effect. In the last part of the paper, the cause of urbanization effects on temperature was discussed. The results indicated: The long term change trend of Shanghai annual mean temperature is 1.31/100a from 1873 to 2004, the periods of 1921 – 1948 and 1979 – 2004 are warmer, and the 1979 – 2004 period is the warmest; compared to suburb stations, the representative urban station has slower decreases in the cool period and faster increases in the warm one; the urban and suburb temperatures have distinct differences resulting from urbanization and the differences are increasing by the year, with the difference of mean temperature and minimum temperature being the greatest in fall and that of maximum temperature being the largest in summer between the urban and suburban areas. The urbanization process accelerates the warming speed, with the minimum temperature being the most obvious; the urbanization effect contributes a 0.4°C increase in 1980s and 1.1°C in 1990s to the annual mean temperature.展开更多
[Objective] The aim was to analyse the variation characteristics of temperature in Anqing City and urban heat island effect.[Method] Based on the observation data of temperature from Anqing Station,other surrounding m...[Objective] The aim was to analyse the variation characteristics of temperature in Anqing City and urban heat island effect.[Method] Based on the observation data of temperature from Anqing Station,other surrounding meteorological stations and local automatic meteorological stations in suburbs,the annual variation of temperature and regional consistency was analysed,then the abrupt change of annual average temperature was tested by Mann-Kendall test,finally the influences of urban heat island effect on temperature variation in Anqing Station were studied.[Result] Affected by station migration and urban construction,the annual average temperature increased significantly in Anqing Station from 1977 to 2009,and the rising was more prominent after the middle of the 1990s.Mann-Kendall test showed that the change of temperature in Anqing Station was obviously abrupt around 1993;because of the development of urbanization,average temperature in Anqing Station was 0.8 ℃ higher than that in suburbs,and the minimum temperature rose more remarkably.In addition,urban heat island effect was the strongest in spring,followed by summer and autumn,while it was the weakest in winter.[Conclusion] The effects of urbanization development on the temperature in Anqing City were understood through this research.展开更多
This paper sets out the preliminary results of an experimental research plan aimed at analysing the thermal processes inherent to the urbanisation effect. Although this effect is undeniable, the extent of its impact i...This paper sets out the preliminary results of an experimental research plan aimed at analysing the thermal processes inherent to the urbanisation effect. Although this effect is undeniable, the extent of its impact is a matter of controversy. The results obtained in this study show both the nature of the phenomenon and its considerable magnitude. Failure to take this process into account might seriously bias any analysis of thermal evolution, the cornerstone of the climate change hypothesis.展开更多
The wet bulb globe temperature(WBGT)has important implication for human health.Previous studies widely use the monthly data but rarely investigate the extreme WBGT because of data limitation.In this study,we use 6-h s...The wet bulb globe temperature(WBGT)has important implication for human health.Previous studies widely use the monthly data but rarely investigate the extreme WBGT because of data limitation.In this study,we use 6-h station data to analyze the changes in the WBGT and three categories(intensity,absolute threshold,and frequency indices)of extreme WBGT indices in summers of 1961-2017.It is found that the spatial distributions of long-term trends in summer mean WBGT are consistent with those in the mean temperature.The trend value of WBGT is smaller than the mean temperature,because of the decrease of relative humidity.For the extreme indices,the intensity and frequency of WBGT and fixed threshold indices have changed.The increase of intensity indices and warm WBGT days and nights,and decrease of cold WBGT days and nights have been observed in most China,especially over northwestern China.The number of days with daily maximum WBGT exceeding 31.4℃(WXge31)and minimum WBGT exceeding 27.9℃(WNge27)over southeastern China have increased since 1961.The spread of probability distributions of WXge31,WNge27,and warm WBGT days and nights is becoming wider,reflecting increased variability of extreme indices.In addition,urbanization effects on the WBGT are investigated.The impacts of urbanization on most of extreme WBGT indices are not detected,except for absolute thresholds indices.This may be due to the decrease of relative humidity in urban stations,which are almost two times larger than that in rural stations.However,we also note that the homogenization issue of humidity data may affect the conclusions.展开更多
以山东和福建为研究区,基于气象站气候观测数据及ERA5-land再分析数据,采用变化趋势分析、观测减再分析(Observation Minus Reanalysis,OMR)和对比分析等方法,在区域尺度上探讨不同气候背景下城市化引起的局地升温差异。结果表明,1987—...以山东和福建为研究区,基于气象站气候观测数据及ERA5-land再分析数据,采用变化趋势分析、观测减再分析(Observation Minus Reanalysis,OMR)和对比分析等方法,在区域尺度上探讨不同气候背景下城市化引起的局地升温差异。结果表明,1987—2017年山东省台站年平均气温平均变化率略高于福建省,分别为0.38℃·(10a)^(-1)和0.33℃·(10a)^(-1),但两省各季节气温变化趋势存在很大差异。城市化对山东省年和各季节T_(mean)变化的影响均大于福建省,北方相对干旱且较长的日照时间更利于城市热岛形成,这是导致上述差异的重要原因。此外,城市化对两省秋、冬季节T_(mean)变化的影响较春、夏季节更大,这与秋、冬季节相对干旱且静稳的气候特征有关。山东省城市化升温幅度的季节性差异较福建省大,可能与北方地区季节气候波动更大有关。展开更多
文摘To understand how temperature varies in urban Shanghai under the background of global climate change and how it is affected by urbanization, the Shanghai temperature responses to global warming were analyzed, and then the temperature trends of urban and suburb stations under different climatic backgrounds were obtained. The urbanization effects on temperature were studied by comparing urban stations to suburb stations, the relationship between urbanization variables and temperature components were obtained, and observation data of surface and high level were combined to assess the contribution of urbanization effect. In the last part of the paper, the cause of urbanization effects on temperature was discussed. The results indicated: The long term change trend of Shanghai annual mean temperature is 1.31/100a from 1873 to 2004, the periods of 1921 – 1948 and 1979 – 2004 are warmer, and the 1979 – 2004 period is the warmest; compared to suburb stations, the representative urban station has slower decreases in the cool period and faster increases in the warm one; the urban and suburb temperatures have distinct differences resulting from urbanization and the differences are increasing by the year, with the difference of mean temperature and minimum temperature being the greatest in fall and that of maximum temperature being the largest in summer between the urban and suburban areas. The urbanization process accelerates the warming speed, with the minimum temperature being the most obvious; the urbanization effect contributes a 0.4°C increase in 1980s and 1.1°C in 1990s to the annual mean temperature.
文摘[Objective] The aim was to analyse the variation characteristics of temperature in Anqing City and urban heat island effect.[Method] Based on the observation data of temperature from Anqing Station,other surrounding meteorological stations and local automatic meteorological stations in suburbs,the annual variation of temperature and regional consistency was analysed,then the abrupt change of annual average temperature was tested by Mann-Kendall test,finally the influences of urban heat island effect on temperature variation in Anqing Station were studied.[Result] Affected by station migration and urban construction,the annual average temperature increased significantly in Anqing Station from 1977 to 2009,and the rising was more prominent after the middle of the 1990s.Mann-Kendall test showed that the change of temperature in Anqing Station was obviously abrupt around 1993;because of the development of urbanization,average temperature in Anqing Station was 0.8 ℃ higher than that in suburbs,and the minimum temperature rose more remarkably.In addition,urban heat island effect was the strongest in spring,followed by summer and autumn,while it was the weakest in winter.[Conclusion] The effects of urbanization development on the temperature in Anqing City were understood through this research.
文摘This paper sets out the preliminary results of an experimental research plan aimed at analysing the thermal processes inherent to the urbanisation effect. Although this effect is undeniable, the extent of its impact is a matter of controversy. The results obtained in this study show both the nature of the phenomenon and its considerable magnitude. Failure to take this process into account might seriously bias any analysis of thermal evolution, the cornerstone of the climate change hypothesis.
基金Supported by the National Key Research and Development Program of China(2018YFC1507702)National Natural Science Foundation of China(42025503)。
文摘The wet bulb globe temperature(WBGT)has important implication for human health.Previous studies widely use the monthly data but rarely investigate the extreme WBGT because of data limitation.In this study,we use 6-h station data to analyze the changes in the WBGT and three categories(intensity,absolute threshold,and frequency indices)of extreme WBGT indices in summers of 1961-2017.It is found that the spatial distributions of long-term trends in summer mean WBGT are consistent with those in the mean temperature.The trend value of WBGT is smaller than the mean temperature,because of the decrease of relative humidity.For the extreme indices,the intensity and frequency of WBGT and fixed threshold indices have changed.The increase of intensity indices and warm WBGT days and nights,and decrease of cold WBGT days and nights have been observed in most China,especially over northwestern China.The number of days with daily maximum WBGT exceeding 31.4℃(WXge31)and minimum WBGT exceeding 27.9℃(WNge27)over southeastern China have increased since 1961.The spread of probability distributions of WXge31,WNge27,and warm WBGT days and nights is becoming wider,reflecting increased variability of extreme indices.In addition,urbanization effects on the WBGT are investigated.The impacts of urbanization on most of extreme WBGT indices are not detected,except for absolute thresholds indices.This may be due to the decrease of relative humidity in urban stations,which are almost two times larger than that in rural stations.However,we also note that the homogenization issue of humidity data may affect the conclusions.
文摘以山东和福建为研究区,基于气象站气候观测数据及ERA5-land再分析数据,采用变化趋势分析、观测减再分析(Observation Minus Reanalysis,OMR)和对比分析等方法,在区域尺度上探讨不同气候背景下城市化引起的局地升温差异。结果表明,1987—2017年山东省台站年平均气温平均变化率略高于福建省,分别为0.38℃·(10a)^(-1)和0.33℃·(10a)^(-1),但两省各季节气温变化趋势存在很大差异。城市化对山东省年和各季节T_(mean)变化的影响均大于福建省,北方相对干旱且较长的日照时间更利于城市热岛形成,这是导致上述差异的重要原因。此外,城市化对两省秋、冬季节T_(mean)变化的影响较春、夏季节更大,这与秋、冬季节相对干旱且静稳的气候特征有关。山东省城市化升温幅度的季节性差异较福建省大,可能与北方地区季节气候波动更大有关。
