Foraminifer is a very useful microorganism to perform biostratigraphical zonation of the Upper Jurassic. Foraminiferal biozones are calibrated by the ammonite standard zones and can be used for intra- and interregiona...Foraminifer is a very useful microorganism to perform biostratigraphical zonation of the Upper Jurassic. Foraminiferal biozones are calibrated by the ammonite standard zones and can be used for intra- and interregional correlations. Furthermore, the fossil record of foraminiferal faunas is well known among basins of the Northern Eurasia and is also used for accurate palaeoenvironmental, palaeobiogeographical, or biofacial reconstructions. It allows identifying a complex set of biotic and abiotic events which may be used to propose a more general palaeoecoloecological and palaeoceanographical reconstruction of the Subboreal, Boreal, and Arctic seas. Then, the late Kimmeridgian Northern Eurasian seas formed a network of well-connected palaeobasins during the sea-level rise and resulted in rather similar palaeoenvironmental conditions.展开更多
本文主要利用美国冰雪资料中心(The National Snow and Ice Data Center)提供的卫星反演积雪资料和ERA40土壤温度再分析资料,采用相关分析,对欧亚北部冬季新增雪盖面积(冬季TFSE)与我国夏季气候异常关系的可能物理途径进行了初步研究。...本文主要利用美国冰雪资料中心(The National Snow and Ice Data Center)提供的卫星反演积雪资料和ERA40土壤温度再分析资料,采用相关分析,对欧亚北部冬季新增雪盖面积(冬季TFSE)与我国夏季气候异常关系的可能物理途径进行了初步研究。结果表明,春夏季陆面季节演变异常是上述"隔季相关"的重要纽带:当冬季TFSE偏大时,欧亚北部大范围积雪—冻土自西向东、由南向北的融化进程明显减慢,受其影响,至夏季,东亚中高纬区积雪和地表冻土的融化异常强烈,土壤温度明显偏低,这种夏季陆面异常可能通过自身的冷却作用,通过加强东亚中高纬异常北风对东亚中纬区夏季变冷产生直接影响,进而与西太平洋副热带高压,乃至与我国江南夏季降水异常产生关联;冬季TFSE偏小时相反。分析表明,冬季TFSE信号在东亚中高纬局地的春季积雪—冻土融化过程中被加强,并在夏季达到显著。展开更多
In this study, interannual variability of summer rainfall over the northern part of China （NPC） and associated circulation patterns were investigated by using long-term （1961-2013） observational and reanalysis dat...In this study, interannual variability of summer rainfall over the northern part of China （NPC） and associated circulation patterns were investigated by using long-term （1961-2013） observational and reanalysis data. Two important NPC rainfall modes were identified by empirical orthogoual function analysis： the first is characterized by an almost uniformly distributed rainfall anomaly over most parts of the NPC, while the second shows rainfall variability in Northeast China （NEC） and its out-of-phase relationship with that in North China （NC） and the northern part of Northwest China. The results also suggest that the NPC summer rainfall anomalies are also closely associated with those in some other parts of China. It is revealed that the circumglobal teleconnection pattern associated with the anomalous Indian summer monsoon （ISM） and the Polar/Eurasia （PEA） pattern work in concert to constitute the typical circulation pattern of the first rainfall mode. The cooperative engagement of the anomalous ISM circulation and the PEA pattern is fundamental in transporting water vapor to the NPC. The study emphasizes that the PEA pattern is essential for the water vapor transport to the NPC through the anomalous midlatitude westerly. In the second NPC rainfall mode, the typical circulation pattern is characterized by the anomalous surface Okhotsk high and the attendant lower tropospheric circulation anomaly over NEC. The circulation anomaly over NEC leads to a redistribution of water vapor fluxes over the NPC and constitutes an out-of-phase relationship between the rainfall anomalies over NEC and NC.展开更多
文摘Foraminifer is a very useful microorganism to perform biostratigraphical zonation of the Upper Jurassic. Foraminiferal biozones are calibrated by the ammonite standard zones and can be used for intra- and interregional correlations. Furthermore, the fossil record of foraminiferal faunas is well known among basins of the Northern Eurasia and is also used for accurate palaeoenvironmental, palaeobiogeographical, or biofacial reconstructions. It allows identifying a complex set of biotic and abiotic events which may be used to propose a more general palaeoecoloecological and palaeoceanographical reconstruction of the Subboreal, Boreal, and Arctic seas. Then, the late Kimmeridgian Northern Eurasian seas formed a network of well-connected palaeobasins during the sea-level rise and resulted in rather similar palaeoenvironmental conditions.
文摘本文主要利用美国冰雪资料中心(The National Snow and Ice Data Center)提供的卫星反演积雪资料和ERA40土壤温度再分析资料,采用相关分析,对欧亚北部冬季新增雪盖面积(冬季TFSE)与我国夏季气候异常关系的可能物理途径进行了初步研究。结果表明,春夏季陆面季节演变异常是上述"隔季相关"的重要纽带:当冬季TFSE偏大时,欧亚北部大范围积雪—冻土自西向东、由南向北的融化进程明显减慢,受其影响,至夏季,东亚中高纬区积雪和地表冻土的融化异常强烈,土壤温度明显偏低,这种夏季陆面异常可能通过自身的冷却作用,通过加强东亚中高纬异常北风对东亚中纬区夏季变冷产生直接影响,进而与西太平洋副热带高压,乃至与我国江南夏季降水异常产生关联;冬季TFSE偏小时相反。分析表明,冬季TFSE信号在东亚中高纬局地的春季积雪—冻土融化过程中被加强,并在夏季达到显著。
基金Supported by the National Natural Science Foundation of China(41375064 and 41630424)National Science and Technology Support Program of China(2015BAC03B03)
文摘In this study, interannual variability of summer rainfall over the northern part of China （NPC） and associated circulation patterns were investigated by using long-term （1961-2013） observational and reanalysis data. Two important NPC rainfall modes were identified by empirical orthogoual function analysis： the first is characterized by an almost uniformly distributed rainfall anomaly over most parts of the NPC, while the second shows rainfall variability in Northeast China （NEC） and its out-of-phase relationship with that in North China （NC） and the northern part of Northwest China. The results also suggest that the NPC summer rainfall anomalies are also closely associated with those in some other parts of China. It is revealed that the circumglobal teleconnection pattern associated with the anomalous Indian summer monsoon （ISM） and the Polar/Eurasia （PEA） pattern work in concert to constitute the typical circulation pattern of the first rainfall mode. The cooperative engagement of the anomalous ISM circulation and the PEA pattern is fundamental in transporting water vapor to the NPC. The study emphasizes that the PEA pattern is essential for the water vapor transport to the NPC through the anomalous midlatitude westerly. In the second NPC rainfall mode, the typical circulation pattern is characterized by the anomalous surface Okhotsk high and the attendant lower tropospheric circulation anomaly over NEC. The circulation anomaly over NEC leads to a redistribution of water vapor fluxes over the NPC and constitutes an out-of-phase relationship between the rainfall anomalies over NEC and NC.
