The authors examine the effects of external forcing agents such as greenhouse gases （GHGs） and aerosols, as well as solar variability and ozone, on global land monsoon precipitation by using a coupled climate model ...The authors examine the effects of external forcing agents such as greenhouse gases （GHGs） and aerosols, as well as solar variability and ozone, on global land monsoon precipitation by using a coupled climate model HadGEM1, which was developed by the Met Office Hadley Centre for Climate Research. The results indicate that HadGEM1 performs well in simulating the observed decreasing trend of global land monsoon precipitation over the past 50 years. This trend mainly occurred in the Northern Hemisphere and is significantly different from the trend of natural variability due to ocean-atmosphere-land interactions. The coherence between the simulation and the observations indicates that the specified external forcing agents, including GHGs and aerosols as well as solar variability and ozone, are important factors that have affected the decreasing trend of global land monsoon precipitation in the past 50 years.展开更多
Changing precipitation in the densely populated Sichuan basin may have a great impact on human life. This study analyzes the change in summer precipitation since 1951 over the western Sichuan basin, one of the regions...Changing precipitation in the densely populated Sichuan basin may have a great impact on human life. This study analyzes the change in summer precipitation since 1951 over the western Sichuan basin, one of the regions of the heaviest rainfall in China, by using two datasets provided by the Chinese Meteorological Data Center. The results indicate that summer (from June to September) precipitation over the western Sichuan basin shows a significantly decreasing trend. The summer precipitation over this region has decreased by about 20% since the 1950s, with a rate of decrease of about 40 mm per decade.展开更多
Alpine wetlands refer to wetland ecosystems distributed at high latitudes and high altitudes that are particularly susceptible to the effects of climate change[1].The Qinghai-Tibetan Plateau(QTP),colloquially known as...Alpine wetlands refer to wetland ecosystems distributed at high latitudes and high altitudes that are particularly susceptible to the effects of climate change[1].The Qinghai-Tibetan Plateau(QTP),colloquially known as the“third pole”of the Earth,is a pivotal region for climate change research and one of the major distribution areas of alpine wetlands in China[2,3].展开更多
Industrialization and urbanization are the most dominant causal factors for long-term changes in surface air temperatures. To examine this fact, the long term changes in the surface-air temperatures have been evaluate...Industrialization and urbanization are the most dominant causal factors for long-term changes in surface air temperatures. To examine this fact, the long term changes in the surface-air temperatures have been evaluated by the linear trend for the different periods, i.e. 1901-2013, 1901-1970 and recent period 1971-2013 as rapid industrialization was observed during the recent four decades. In the present study, seasonal and annual mean, maximum and minimum temperature data of 36 stations for the period 1901-2013 have been used. These stations are classified into 4 groups, namely major, medium, small cities and hill stations. During the period 1901-1970, less than 50% stations from each group showed a significant increasing trend in annual mean temperature, whereas in the recent period 1971-2013, more than 80% stations from all the groups except small city group showed a significant increasing trend. The minimum temperature increased faster than that of the maximum temperature over major and medium cities, while maximum temperature increased faster than the minimum temperature over the small cities and hill stations. The annual mean temperature of all the coastal stations showed a significant increasing trend and positive correlation with Precipitable Water Vapour (PWV). The effect of PWV is more pronounced on minimum temperature than that of the maximum.展开更多
This paper reviewed the main results with respect to the discovery of low center of total column ozone （TCO） over the Tibetan Plateau （TP） in summer, and its formation mechanism. Some important advances are summar...This paper reviewed the main results with respect to the discovery of low center of total column ozone （TCO） over the Tibetan Plateau （TP） in summer, and its formation mechanism. Some important advances are summarized as follows： The fact is discovered that there is a TCO low center over the TP in summer, and the features of the background circulation over the TP are analyzed; it is confirmed that the TP is a pathway of mass exchange between the troposphere and stratosphere, and it influences the TCO low center over the TP in summer; models reproduce the TCO low center over the TP in summer, and the formation mecbanism is explored; in addition, the analyses and diagnoses of the observation data indicate that not only there is the TCO low center over the TP in summer, but also TCO decrease trend over the TP is one of the strong centers of TCO decrease trend in the same latitude; finally, the model predicts the future TCO change over the TP.展开更多
基金supported by National Natural Science Foundation of China under GrantNos. 40625014, 40821092, and 90711004the National Basic Research Program of China (2006CB403603)the China Meteorological Administration (GYHY200706010,GYHY200706005)
文摘The authors examine the effects of external forcing agents such as greenhouse gases （GHGs） and aerosols, as well as solar variability and ozone, on global land monsoon precipitation by using a coupled climate model HadGEM1, which was developed by the Met Office Hadley Centre for Climate Research. The results indicate that HadGEM1 performs well in simulating the observed decreasing trend of global land monsoon precipitation over the past 50 years. This trend mainly occurred in the Northern Hemisphere and is significantly different from the trend of natural variability due to ocean-atmosphere-land interactions. The coherence between the simulation and the observations indicates that the specified external forcing agents, including GHGs and aerosols as well as solar variability and ozone, are important factors that have affected the decreasing trend of global land monsoon precipitation in the past 50 years.
基金supported by the National Basic Research Program of China(Grant No.2009CB421400)the National Natural Science Foundation of China(Grant No.40725016)
文摘Changing precipitation in the densely populated Sichuan basin may have a great impact on human life. This study analyzes the change in summer precipitation since 1951 over the western Sichuan basin, one of the regions of the heaviest rainfall in China, by using two datasets provided by the Chinese Meteorological Data Center. The results indicate that summer (from June to September) precipitation over the western Sichuan basin shows a significantly decreasing trend. The summer precipitation over this region has decreased by about 20% since the 1950s, with a rate of decrease of about 40 mm per decade.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)Program(2019QZKK0106)the National Natural Science Foundation of China(41971390).
文摘Alpine wetlands refer to wetland ecosystems distributed at high latitudes and high altitudes that are particularly susceptible to the effects of climate change[1].The Qinghai-Tibetan Plateau(QTP),colloquially known as the“third pole”of the Earth,is a pivotal region for climate change research and one of the major distribution areas of alpine wetlands in China[2,3].
文摘Industrialization and urbanization are the most dominant causal factors for long-term changes in surface air temperatures. To examine this fact, the long term changes in the surface-air temperatures have been evaluated by the linear trend for the different periods, i.e. 1901-2013, 1901-1970 and recent period 1971-2013 as rapid industrialization was observed during the recent four decades. In the present study, seasonal and annual mean, maximum and minimum temperature data of 36 stations for the period 1901-2013 have been used. These stations are classified into 4 groups, namely major, medium, small cities and hill stations. During the period 1901-1970, less than 50% stations from each group showed a significant increasing trend in annual mean temperature, whereas in the recent period 1971-2013, more than 80% stations from all the groups except small city group showed a significant increasing trend. The minimum temperature increased faster than that of the maximum temperature over major and medium cities, while maximum temperature increased faster than the minimum temperature over the small cities and hill stations. The annual mean temperature of all the coastal stations showed a significant increasing trend and positive correlation with Precipitable Water Vapour (PWV). The effect of PWV is more pronounced on minimum temperature than that of the maximum.
文摘This paper reviewed the main results with respect to the discovery of low center of total column ozone （TCO） over the Tibetan Plateau （TP） in summer, and its formation mechanism. Some important advances are summarized as follows： The fact is discovered that there is a TCO low center over the TP in summer, and the features of the background circulation over the TP are analyzed; it is confirmed that the TP is a pathway of mass exchange between the troposphere and stratosphere, and it influences the TCO low center over the TP in summer; models reproduce the TCO low center over the TP in summer, and the formation mecbanism is explored; in addition, the analyses and diagnoses of the observation data indicate that not only there is the TCO low center over the TP in summer, but also TCO decrease trend over the TP is one of the strong centers of TCO decrease trend in the same latitude; finally, the model predicts the future TCO change over the TP.
