Based on the initial field temperature data of ECMWF 850 hPa from Jan- uary 2012 to December 2015, linear interpolation method of ECMWF was employed to calculate the 850 hPa temperature values at 8：00 and 20：00 of 7...Based on the initial field temperature data of ECMWF 850 hPa from Jan- uary 2012 to December 2015, linear interpolation method of ECMWF was employed to calculate the 850 hPa temperature values at 8：00 and 20：00 of 7 stations （Jiamusi, Tangyuan, Huachuan, Huanan, Fujin, Tongjiang, Fuyuan）. Combined with the observed daily minimum and maximum air temperatures at the same time of the 7 stations, the correlations of the 850 hPa temperature values at 8：00 and 20：00 with the daily maximum or minimum air temperature of the ground meteorological obser- vation stations were established, and the ground observation data in accordance with the relevant analysis and correlation test principle of the prediction equation for factor were primarily selected. Regression method was used to establish forecast e- quation dividing into counties, month by month. The results showed that the 850 hPa temperature values at 8：00 and 20：00 were significantly correlated with the daily maximum or minimum air temperature, and the established temperature fore- cast equation was of certain guiding significance for the forecast of daily minimum and maximum temperature, which could help to improve the forecast accuracy.展开更多
The changes in a selection of extreme climate indices(maximum of daily maximum temperature(TXx),minimum of daily minimum temperature(TNn),annual total precipitation when the daily precipitation exceeds the 95th percen...The changes in a selection of extreme climate indices(maximum of daily maximum temperature(TXx),minimum of daily minimum temperature(TNn),annual total precipitation when the daily precipitation exceeds the 95th percentile of wet-day precipitation(very wet days,R95p),and the maximum number of consecutive days with less than 1 mm of precipitation(consecutive dry days,CDD))were projected using multi-model results from phase 5 of the Coupled Model Intercomparison Project in the early,middle,and latter parts of the 21st century under different Representative Concentration Pathway(RCP)emissions scenarios.The results suggest that TXx and TNn will increase in the future and,moreover,the increases of TNn under all RCPs are larger than those of TXx.R95p is projected to increase and CDD to decrease significantly.The changes in TXx,TNn,R95p,and CDD in eight sub-regions of China are different in the three periods of the 21st century,and the ranges of change for the four indices under the higher emissions scenario are projected to be larger than those under the lower emissions scenario.The multi-model simulations show remarkable consistency in their projection of the extreme temperature indices,but poor consistency with respect to the extreme precipitation indices.More substantial inconsistency is found in those regions where high and low temperatures are likely to happen for TXx and TNn,respectively.For extreme precipitation events(R95p),greater uncertainty appears in most of the southern regions,while for drought events(CDD)it appears in the basins of Xinjiang.The uncertainty in the future changes of the extreme climate indices increases with the increasing severity of the emissions scenario.展开更多
Based on the observations from 239 meteorological stations located in Central China （Henan, Hubei and Hunan provinces）, this paper focuses on the climate change facts during 1961- 2010. There was a significant incre...Based on the observations from 239 meteorological stations located in Central China （Henan, Hubei and Hunan provinces）, this paper focuses on the climate change facts during 1961- 2010. There was a significant increasing trend in annual mean temperature for Central China during 1961 -2010. The increasing rate was 0.15℃ per decade, which was lower than the national trend. Since the mid-1980s, temperature increasing was obvious. Large increasing rate was observed in the mid-eastern part of Central China. For the four seasons, the increasing rate in winter was the largest （0.27℃ per decade）. The increasing rate in the annual mean minimum temperature was larger than that in the annual mean maximum temperature from 1961 to 2010. As a result, the diurnal range of temperature decreased at the rate of -0.10℃ per decade. The extreme high temperature events were increasing while the extreme low temperature events were significantly decreasing. There was no obvious trend in annual precipitation for Central China during 1961-2010. Precipitation in summer and winter significantly increased; change of precipitation in spring was not obvious; precipitation in autumn was decreasing. The decreasing rate of annual rainy days was -3.4 d per decade. The precipitation intensity increased at the rate of 0.25 mm d-1 per decade. Heavy-rain days significantly increased. Spring and summer started earlier while autumn and winter started later. As a result, spring and summer duration was expanding whereas autumn and winter duration shortened.展开更多
Change related to climate in Macao was studied on the basis of daily temperature observations over the period 1901-2007. The result shows that annual mean surface air temperature in Macao as a whole rose with a warmin...Change related to climate in Macao was studied on the basis of daily temperature observations over the period 1901-2007. The result shows that annual mean surface air temperature in Macao as a whole rose with a warming rate of about 0.066℃ per 10 years in the recent 107 years. The most evident warming occurred in spring and winter. The interdecadal variations of the seasonal mean temperature in summer and winter appeared as a series of waves with a time scale of about 30 years and 60 years, respectively. The annual mean minimum temperature increased about twice as fast as the annual mean maximum temperature, resulting in a broad decline in the annual mean diurnal range. The interdecadal variations of annual mean maximum temperature are obviously different from those of annual mean minimum temperature. It appears that the increase in the annual mean maximum temperature in the recent 20 years may be part of slow climate fluctuations with a periodicity of about 60 years, whereas that in the annual mean minimum temperature appears to be the continuation of a long-term warming trend.展开更多
The contributions of urban surface expansion to regional warming over subregions of Shanghai and Shanghai as a whole using different methods to calculate the daily mean surface temperature(SAT),including the averages ...The contributions of urban surface expansion to regional warming over subregions of Shanghai and Shanghai as a whole using different methods to calculate the daily mean surface temperature(SAT),including the averages of four daily time-records(0000,0600,1200,and 1800 UTC;T4),eight daily time-records(0000,0300,0600,0900,1200,1500,1800,and 2100 UTC;T8),and the averages of the SAT maximum(Tmax)and minimum(Tmin),Txn,were compared based on simulated results using nested numerical intergrations with the Weather Research and Forecasting regional climate model,where only the satellite-retrieved urban surface distributions differed between two numerical experiments.The contributions from urban-related warming expressed similar intensities when using T8 and Txn,while the smallest values occurred when using T4 over different subregions of Shanghai(with the exception of areas that were defined as urban for both time periods(U2U))and Shanghai as a whole.Similar values for the changing trends could be detected over different subregions when no urban surface expansion(EX1)was detected for both T4 and Txn.The corresponding values increased under urban surface expansion(EX2)and varied over different subregions,revealing much stronger intensities over urban-surface expansion areas;the weakest intensities occurred over U2U areas.The increasing trends for EX2 and relative contributions when using T4 were smaller than those when using Txn,with the exception of those over U2U areas,which could be explained by the changing trends in Tmax and Tmin due to urban surface expansion,especially during intense urban expansion periods.展开更多
This paper demonstrates regional characteristics, a long-term decreasing trend, and decadal variations in the frequency of cold surge events based on daily mean temperature and daily minimum temperature data in China&...This paper demonstrates regional characteristics, a long-term decreasing trend, and decadal variations in the frequency of cold surge events based on daily mean temperature and daily minimum temperature data in China's Mainland from 1960 to 2008. During these 48 years four high frequency centers of cold surge events were located in Xinjiang, central North China, northeast China, and southeast China. A main frequency peak of cold surge events occurs in autumn for the four regions and another peak is detected in spring over northeast China and southeast China. The regional pattern of cold surge frequencies is in accordance with the perturbation kinetic energy distribution in October December, January, and February April. The long-term decreasing trend ( 0.2 times/decade) of cold surge frequencies in northeast China and decadal variations in China are related to the variations of the temperature difference between southern and northern China in the winter monsoon season; these variations are due to the significant rising of winter temperatures in high latitudes.展开更多
文摘Based on the initial field temperature data of ECMWF 850 hPa from Jan- uary 2012 to December 2015, linear interpolation method of ECMWF was employed to calculate the 850 hPa temperature values at 8：00 and 20：00 of 7 stations （Jiamusi, Tangyuan, Huachuan, Huanan, Fujin, Tongjiang, Fuyuan）. Combined with the observed daily minimum and maximum air temperatures at the same time of the 7 stations, the correlations of the 850 hPa temperature values at 8：00 and 20：00 with the daily maximum or minimum air temperature of the ground meteorological obser- vation stations were established, and the ground observation data in accordance with the relevant analysis and correlation test principle of the prediction equation for factor were primarily selected. Regression method was used to establish forecast e- quation dividing into counties, month by month. The results showed that the 850 hPa temperature values at 8：00 and 20：00 were significantly correlated with the daily maximum or minimum air temperature, and the established temperature fore- cast equation was of certain guiding significance for the forecast of daily minimum and maximum temperature, which could help to improve the forecast accuracy.
基金supported by the R&D Special Fund for Public Welfare Industry (Meteorology) (Grant No. GYHY201306019)the National Natural Science Foundation of China (Grant No. 41275078)
文摘The changes in a selection of extreme climate indices(maximum of daily maximum temperature(TXx),minimum of daily minimum temperature(TNn),annual total precipitation when the daily precipitation exceeds the 95th percentile of wet-day precipitation(very wet days,R95p),and the maximum number of consecutive days with less than 1 mm of precipitation(consecutive dry days,CDD))were projected using multi-model results from phase 5 of the Coupled Model Intercomparison Project in the early,middle,and latter parts of the 21st century under different Representative Concentration Pathway(RCP)emissions scenarios.The results suggest that TXx and TNn will increase in the future and,moreover,the increases of TNn under all RCPs are larger than those of TXx.R95p is projected to increase and CDD to decrease significantly.The changes in TXx,TNn,R95p,and CDD in eight sub-regions of China are different in the three periods of the 21st century,and the ranges of change for the four indices under the higher emissions scenario are projected to be larger than those under the lower emissions scenario.The multi-model simulations show remarkable consistency in their projection of the extreme temperature indices,but poor consistency with respect to the extreme precipitation indices.More substantial inconsistency is found in those regions where high and low temperatures are likely to happen for TXx and TNn,respectively.For extreme precipitation events(R95p),greater uncertainty appears in most of the southern regions,while for drought events(CDD)it appears in the basins of Xinjiang.The uncertainty in the future changes of the extreme climate indices increases with the increasing severity of the emissions scenario.
基金supported by the Climate Change Special Project of China Meteorological Administration:The Assessment Report Preparation of the Climate Change of Central China (No. CCSF-10-04)
文摘Based on the observations from 239 meteorological stations located in Central China （Henan, Hubei and Hunan provinces）, this paper focuses on the climate change facts during 1961- 2010. There was a significant increasing trend in annual mean temperature for Central China during 1961 -2010. The increasing rate was 0.15℃ per decade, which was lower than the national trend. Since the mid-1980s, temperature increasing was obvious. Large increasing rate was observed in the mid-eastern part of Central China. For the four seasons, the increasing rate in winter was the largest （0.27℃ per decade）. The increasing rate in the annual mean minimum temperature was larger than that in the annual mean maximum temperature from 1961 to 2010. As a result, the diurnal range of temperature decreased at the rate of -0.10℃ per decade. The extreme high temperature events were increasing while the extreme low temperature events were significantly decreasing. There was no obvious trend in annual precipitation for Central China during 1961-2010. Precipitation in summer and winter significantly increased; change of precipitation in spring was not obvious; precipitation in autumn was decreasing. The decreasing rate of annual rainy days was -3.4 d per decade. The precipitation intensity increased at the rate of 0.25 mm d-1 per decade. Heavy-rain days significantly increased. Spring and summer started earlier while autumn and winter started later. As a result, spring and summer duration was expanding whereas autumn and winter duration shortened.
文摘Change related to climate in Macao was studied on the basis of daily temperature observations over the period 1901-2007. The result shows that annual mean surface air temperature in Macao as a whole rose with a warming rate of about 0.066℃ per 10 years in the recent 107 years. The most evident warming occurred in spring and winter. The interdecadal variations of the seasonal mean temperature in summer and winter appeared as a series of waves with a time scale of about 30 years and 60 years, respectively. The annual mean minimum temperature increased about twice as fast as the annual mean maximum temperature, resulting in a broad decline in the annual mean diurnal range. The interdecadal variations of annual mean maximum temperature are obviously different from those of annual mean minimum temperature. It appears that the increase in the annual mean maximum temperature in the recent 20 years may be part of slow climate fluctuations with a periodicity of about 60 years, whereas that in the annual mean minimum temperature appears to be the continuation of a long-term warming trend.
基金This work was supported by the National Natural Science Foundation of China [grant numbers 41775087 and41675149]the National Key R&D Program of China [grant number 2016YFA0600403]+2 种基金the Chinese Academy of Sciences Strategic Priority Program [grant number XDA05090206]the National Key Basic Research Program on Global Change [grant number 2011CB952003]the Jiangsu Collaborative Innovation Center for Climatic Change
文摘The contributions of urban surface expansion to regional warming over subregions of Shanghai and Shanghai as a whole using different methods to calculate the daily mean surface temperature(SAT),including the averages of four daily time-records(0000,0600,1200,and 1800 UTC;T4),eight daily time-records(0000,0300,0600,0900,1200,1500,1800,and 2100 UTC;T8),and the averages of the SAT maximum(Tmax)and minimum(Tmin),Txn,were compared based on simulated results using nested numerical intergrations with the Weather Research and Forecasting regional climate model,where only the satellite-retrieved urban surface distributions differed between two numerical experiments.The contributions from urban-related warming expressed similar intensities when using T8 and Txn,while the smallest values occurred when using T4 over different subregions of Shanghai(with the exception of areas that were defined as urban for both time periods(U2U))and Shanghai as a whole.Similar values for the changing trends could be detected over different subregions when no urban surface expansion(EX1)was detected for both T4 and Txn.The corresponding values increased under urban surface expansion(EX2)and varied over different subregions,revealing much stronger intensities over urban-surface expansion areas;the weakest intensities occurred over U2U areas.The increasing trends for EX2 and relative contributions when using T4 were smaller than those when using Txn,with the exception of those over U2U areas,which could be explained by the changing trends in Tmax and Tmin due to urban surface expansion,especially during intense urban expansion periods.
基金supported jointly by the National Natural Science Foundation of China (40975039)the National Basic Research Program of China (2006CB400504/ 2009CB421401 and GYHY20070605)
文摘This paper demonstrates regional characteristics, a long-term decreasing trend, and decadal variations in the frequency of cold surge events based on daily mean temperature and daily minimum temperature data in China's Mainland from 1960 to 2008. During these 48 years four high frequency centers of cold surge events were located in Xinjiang, central North China, northeast China, and southeast China. A main frequency peak of cold surge events occurs in autumn for the four regions and another peak is detected in spring over northeast China and southeast China. The regional pattern of cold surge frequencies is in accordance with the perturbation kinetic energy distribution in October December, January, and February April. The long-term decreasing trend ( 0.2 times/decade) of cold surge frequencies in northeast China and decadal variations in China are related to the variations of the temperature difference between southern and northern China in the winter monsoon season; these variations are due to the significant rising of winter temperatures in high latitudes.
