| 摘要: |
| 湖泊水位升降反映了流域降水与蒸发的水量平衡变化。古湖面变化能够提供晚第四纪以来降水和湿度变化的气候信息。区域性湖泊水位的同步变化可以过滤掉个别湖泊受局部地域影响的水面变动,从而反应出较大范围的气候变化。建立区域性乃至全球性的古湖泊数据库反映这样的客观要求。目前,湖泊数据库在大陆尺度上恢复晚第四纪以来大气环流类型和在对比全球古大气环流模型中发挥着积极作用。本文通过作者近年来对欧洲古湖泊数据库的研究,介绍建立湖泊数据库的基础、方法和应用。希望藉此能够促进中国晚第四纪湖泊数据库的研究,并以此推动建立全球晚第四纪湖泊数据库的进展。 |
| 关键词: 晚第四纪湖泊 数据库 欧亚大陆 |
| DOI：10.18307/1997.0301 |
| 分类号: |
| 基金项目:美国海洋大气局/美国地学资料中心(NOAA/NGDC)资助 |
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| Studies on global late quaternary lake-level data bases |
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Ge Yu1,2
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1.Department of Geo & Ocean Sciences, Nanjing University, Nanjing 210093, P.R.China;2.Dynamic Palaeoclimatology, Lund University, Box 117, S-22100 Lund, Sweden
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| Abstract: |
| Fluctuations of lake status reflect changes in water balance of precipitation minus evaporation (P-E) over a catchment. The ancient lake status can provide information of precipitation and humidity during the late Quaternary. Synchronous changes in regional lake status may keep lake levels from being influenced by non-climatic factors or local factors. The recognition that lake data could be used to reconstruct past regional climate changes leads to the construction of a global lake-level data base. Nowadays, Quaternary Lake status data bases have played a key role in reconstructions of continental-scale atmospheric circulation patterns and are used to compare and evaluate the simulations of precipitation and P-E from the atmospheric general circulation models. Lake records from North Eurasia show regionally-coherent patterns of changes during the late Quaternary. Lakes, peripheral to the Scandinavian ice sheets were lower than today at the glacial maximum, but high in the Mediterranean zone, reflecting the dominance of glacial anticyclonic conditions in North Europe and a southward shift of the westerlies. The influence of the glacial anticyclonic circulation attenuated in the late glacial period, and the westerlies gradually shifted northward, so that drier conditions in south of the ice sheet were confined to a progressively narrower zone in North Europe, and the Mediterranean zone became drier. During the Holocene. there was a gradual shift to conditions wetter than present in central Asia, associated with the expanded Asian monsoon, and in the Mediterranean, in response to a local, monsoon-type circulation. Conditions were drier in North Europe, reflecting the increased incidence of blocking anticyclones centred on Scandinavia. Conditions in the interior of North Euravsia were similar or slightly wetter than present, likely associated with cyclonic activity on the dowiivStream limb of the summer anticyclone in the west and monsoon penetration in the east. These reflect thechanges in insolation and glacial boundary conditions. Simulations of the response to insolation forcing at 6000 yrBP made with five different AGCMs show some common features, e. g, more humid than today in the mid-latitudes of Eurasian continent, enhancement of the Afro-Asian monsoons, drier conditions in North Europe but wetter conditions in the Mediterraneanregion. By comparing the lake data with simulated P-E fields basis can be provided forunderstanding the observed climatic changes and for evaluating the climate model simulations. Thus the paper introduced the work on European lake status database and discussed the basis, methods and applications of the data bases, in order to improve work on the Chinese data base and speed the global data base. |
| Key words: Late Quaternary lakt-level the data base Eurasian continent |
