Based on daily mean temperature records from 1961 to 2007 at 20 meteorological sites in Southwest Yunnan, and the surface temperature simulated by IPCC AR4 Climate Models, a quantitative examination was undertaken int...Based on daily mean temperature records from 1961 to 2007 at 20 meteorological sites in Southwest Yunnan, and the surface temperature simulated by IPCC AR4 Climate Models, a quantitative examination was undertaken into the characteristics of multi-timescale temperature （AMT, DMT and WMT） variation in Southwest Yunnan. The simulation abilities of the models were also evaluated with the normalized root mean square error （NRMSE） and Mann-Kendal test statistic methods. Temperatures show remarkable increasing trend from 1961 to 2007, with the Mann-Kendall test statistic passing 95% confidence verification. The result of the NRMSE analysis shows that the simulated temperature anomaly variations are more similar to observed ones especially for AMT and DMT, and the projected result （anomalies） of IPCC AR4 climate models can be used for predicting the trends in multi-timescale temperature variation in Southwest Yunnan in the next 40 years under the three emission scenarios, which has better simulating effect on AMT and DMT than WMT. Over the next 40 years the temperature will continue to rise, with annual mean temperature showing a more remarkable rising trend than that of the dry and wet seasons. Temperature anomalies exhibit different increasing rates under different emission scenarios： During the 2020s the rising rates of multi-timescale temperature anomalies in a high greenhouse gases emissions scenario （SRESA2） are smaller than those under a low emission scenario （SRESB1）. Except that, the rate of increase in temperature anomalies are the highest in the intermediate emissions scenario （SRESA1B）, followed by those in SRESA2, and those in low emissions scenario （SRESB1） are the lowest. The reason of different simulating effects on WMT from AMT and DMT was also discussed.展开更多
Recent studies showed that the Himalayan glaciers are reducing alarmingly. This is attributed to global warming. Since the melt water of Himalayan glaciers and snow is the principal source of water for several rivers,...Recent studies showed that the Himalayan glaciers are reducing alarmingly. This is attributed to global warming. Since the melt water of Himalayan glaciers and snow is the principal source of water for several rivers, a decrease of this source is a calamity for the large fraction of global population living in nearby regions such as India. In Asia for the 60% global population only 36% of global water is available. Any further decrease of this vital necessity makes the very existence of billions of people doubtful. Here we show, using both observations and one IPCC-AR4 model with high horizontal resolution, that the Himalayan region in fact underwent a maximum warming of 2.5°C from 1950 to 1999 and would reach the highest temperature rise of 9°C in 2100. Temperature and rainfall variations determine a simple climate classification proposed by Köppen. We show changes that occur in climate and biosphere using this classification. Also we discussed the impact of warming and resulting changes in Köppen climates on the floods and malaria in India.展开更多
基金National Natural Science Foundation of China (40901050), National Basic Research Program of China (No. 2012CB955903)Scientific Research Fund Project of Yunnan Provincial Department of Education (No. 09Y0284, "Technology Research of Adaptation and Mitigation to Yunnan Climate Change")
文摘Based on daily mean temperature records from 1961 to 2007 at 20 meteorological sites in Southwest Yunnan, and the surface temperature simulated by IPCC AR4 Climate Models, a quantitative examination was undertaken into the characteristics of multi-timescale temperature （AMT, DMT and WMT） variation in Southwest Yunnan. The simulation abilities of the models were also evaluated with the normalized root mean square error （NRMSE） and Mann-Kendal test statistic methods. Temperatures show remarkable increasing trend from 1961 to 2007, with the Mann-Kendall test statistic passing 95% confidence verification. The result of the NRMSE analysis shows that the simulated temperature anomaly variations are more similar to observed ones especially for AMT and DMT, and the projected result （anomalies） of IPCC AR4 climate models can be used for predicting the trends in multi-timescale temperature variation in Southwest Yunnan in the next 40 years under the three emission scenarios, which has better simulating effect on AMT and DMT than WMT. Over the next 40 years the temperature will continue to rise, with annual mean temperature showing a more remarkable rising trend than that of the dry and wet seasons. Temperature anomalies exhibit different increasing rates under different emission scenarios： During the 2020s the rising rates of multi-timescale temperature anomalies in a high greenhouse gases emissions scenario （SRESA2） are smaller than those under a low emission scenario （SRESB1）. Except that, the rate of increase in temperature anomalies are the highest in the intermediate emissions scenario （SRESA1B）, followed by those in SRESA2, and those in low emissions scenario （SRESB1） are the lowest. The reason of different simulating effects on WMT from AMT and DMT was also discussed.
文摘Recent studies showed that the Himalayan glaciers are reducing alarmingly. This is attributed to global warming. Since the melt water of Himalayan glaciers and snow is the principal source of water for several rivers, a decrease of this source is a calamity for the large fraction of global population living in nearby regions such as India. In Asia for the 60% global population only 36% of global water is available. Any further decrease of this vital necessity makes the very existence of billions of people doubtful. Here we show, using both observations and one IPCC-AR4 model with high horizontal resolution, that the Himalayan region in fact underwent a maximum warming of 2.5°C from 1950 to 1999 and would reach the highest temperature rise of 9°C in 2100. Temperature and rainfall variations determine a simple climate classification proposed by Köppen. We show changes that occur in climate and biosphere using this classification. Also we discussed the impact of warming and resulting changes in Köppen climates on the floods and malaria in India.
