Historical simulations (present climate) and projections under RCP8.5 scenario (future climate) by HadGEM2-ES of temperature and precipitation are analyzed during the four seasons in South America. Projections of prec...Historical simulations (present climate) and projections under RCP8.5 scenario (future climate) by HadGEM2-ES of temperature and precipitation are analyzed during the four seasons in South America. Projections of precipitation are discussed in terms of atmospheric circulation. The South Atlantic Convergence Zone (SACZ) and the Pacific South America (PSA) patterns are analyzed in simulations of present climate and in future climate projections. The model shows small systematic errors over South America, larger close to the northern South American coast in DJF and MAM. The seasonal variability of precipitation, temperature and wind fields is very well reproduced, mainly the summer/winter differences. The SACZ and the Intertropical Convergence Zone (ITCZ) are well simulated. The good model performance to reproduce the precipitation, temperature and wind fields, in the present climate, gives confidence in the projection results subject to the future scenarios. Changes from the present time to the future indicate increased precipitation over southern and southeastern Brazil and areas nearby and the tropical western South American coast. Reduced precipitation is projected over eastern Amazonia, northern South America and southern Chile. The changes are related to changes in the low level wind flow over the tropical North Atlantic, which reduces the advection of moisture to the continent and also to the increased low level flow over central South America southwards, which increases the humidity in the southern regions. The upper level flow changes are also consistent with the precipitation changes. There is a weakening of the Bolivian High and a strengthening of the subtropical jet over the continent. The SACZ dipole pattern is well simulated and in the future projections the southern center anomalies are more intense than in the present time. The PSA1 and PSA2 patterns are well represented in the present climate, but in the future projection only one dominant mode is identified as the typical teleconnection over the Pacific and South America.展开更多
Invasive plant species and climate change are among the biggest threats to the ecological integrity of many ecosystems,including those of protected areas.Effective management of invasive plants requires information re...Invasive plant species and climate change are among the biggest threats to the ecological integrity of many ecosystems,including those of protected areas.Effective management of invasive plants requires information regarding their spatialdistributions Using maximum entropy,wemodeled habitat suitability for an invasive plant species Chromolaena odorata under current and future climatic conditions(HadGEM2-ESand MIROC5)in protected areas of four West African countries(Benin,Cote d'voire,Ghana,and Togo).Under current climatic conditions,approximately 73%of total land area within the protected areas was suitable for colonization by C.odorata.Under future climate projections,the total area of suitable habitats for this invasive plant was projected to decrease by 7-9%(HadGEM2-ES)and 12-14%(MIROC5).Country-specific patterns suggest that major protected areas in Cote d'Ivoire and Ghana will be more vulnerable to invasion by C.odorata than those in Benin and Togo under both current and future dimatic scenarios.To maintain normal ecosystem functioning and provisioning of ecosystem services within the protected areas studied here,locations that have been identified as most vulnerable to invasion by C.odorata should be accorded proportionately higher priority when formulating appropriate management strategies.展开更多
基金We thanks CNPq and Claris-LPB for research support.The research leading to these results has received funding from the European Community’s Seventh Framework Program-me(FP7/2007-2013)under Grant Agreement No.212492:CLARIS LPB.
文摘Historical simulations (present climate) and projections under RCP8.5 scenario (future climate) by HadGEM2-ES of temperature and precipitation are analyzed during the four seasons in South America. Projections of precipitation are discussed in terms of atmospheric circulation. The South Atlantic Convergence Zone (SACZ) and the Pacific South America (PSA) patterns are analyzed in simulations of present climate and in future climate projections. The model shows small systematic errors over South America, larger close to the northern South American coast in DJF and MAM. The seasonal variability of precipitation, temperature and wind fields is very well reproduced, mainly the summer/winter differences. The SACZ and the Intertropical Convergence Zone (ITCZ) are well simulated. The good model performance to reproduce the precipitation, temperature and wind fields, in the present climate, gives confidence in the projection results subject to the future scenarios. Changes from the present time to the future indicate increased precipitation over southern and southeastern Brazil and areas nearby and the tropical western South American coast. Reduced precipitation is projected over eastern Amazonia, northern South America and southern Chile. The changes are related to changes in the low level wind flow over the tropical North Atlantic, which reduces the advection of moisture to the continent and also to the increased low level flow over central South America southwards, which increases the humidity in the southern regions. The upper level flow changes are also consistent with the precipitation changes. There is a weakening of the Bolivian High and a strengthening of the subtropical jet over the continent. The SACZ dipole pattern is well simulated and in the future projections the southern center anomalies are more intense than in the present time. The PSA1 and PSA2 patterns are well represented in the present climate, but in the future projection only one dominant mode is identified as the typical teleconnection over the Pacific and South America.
基金We acknowledge funding from International Young Scientist Fellowship of the Chinese Academy of Sciences(fellowship number 2012Y1ZA0009 for A.B.Fandohan and 2012Y1ZA0011 for A.M.O.Oduor)research grants from the National Natural Science Foundation of China(grant number 312111172 for A.B.Fandohan and 312111182 for A.M.O.Oduor).
文摘Invasive plant species and climate change are among the biggest threats to the ecological integrity of many ecosystems,including those of protected areas.Effective management of invasive plants requires information regarding their spatialdistributions Using maximum entropy,wemodeled habitat suitability for an invasive plant species Chromolaena odorata under current and future climatic conditions(HadGEM2-ESand MIROC5)in protected areas of four West African countries(Benin,Cote d'voire,Ghana,and Togo).Under current climatic conditions,approximately 73%of total land area within the protected areas was suitable for colonization by C.odorata.Under future climate projections,the total area of suitable habitats for this invasive plant was projected to decrease by 7-9%(HadGEM2-ES)and 12-14%(MIROC5).Country-specific patterns suggest that major protected areas in Cote d'Ivoire and Ghana will be more vulnerable to invasion by C.odorata than those in Benin and Togo under both current and future dimatic scenarios.To maintain normal ecosystem functioning and provisioning of ecosystem services within the protected areas studied here,locations that have been identified as most vulnerable to invasion by C.odorata should be accorded proportionately higher priority when formulating appropriate management strategies.
