High Resolution ENSO and Other Paleoenvironmental Data for the last 20 ka from Cave Speleothems in Madagascar and Botswana

这一建议要求支持对非洲古气候进行高分辨率研究。 由于马达加斯加西北部和博茨瓦纳的气候受到ENSO事件的显著影响，古环境记录也是SST和El Nino频率的替代记录。厄尔尼诺现象给马达加斯加西北部带来了高于平均水平的降雨，给博茨瓦纳带来了低于平均水平的降雨。来自博茨瓦纳的石笋长达57厘米，可以提供该地区过去2000年的高分辨率记录。来自马达加斯加的石笋组，其中一个石笋约3米长，可以提供一个高分辨率的记录，可能到15-20万年前。该提案要求提供资金，充分开发这些石笋提供高分辨率区域古环境信息的潜力，以及关于SST和ENSO、del-13 C的变化、腐殖酸和富里酸的紫外线激发发光、颗粒物质、岩相学、层厚、包裹体频率和石笋生长轴沿着的灰度级的数据，这些数据将与区域降雨量和温度、海洋SST、厄尔尼诺频率和南方涛动特征。

AbstractThis proposal requests support for a high-resolution study of paleoclimate in Africa. Because the climates of northwest Madagascar and Botswana are affected significantly by ENSO events, paleoenvironmental records are also proxy records of SST and El Nino frequency. El Nino events bring above-average rainfall to northwest Madagascar and below-average rainfall to Botswana. Stalagmites from Botswana, ranging up to 57 cm long, can provide a high-resolution record for this area for the last 2000 years. Formations from Madagascar, with one stalagmite almost 3 m long, can provide a high-resolution record possibly to 15-20 ka ago. This proposal requests funds to fully explore the potential of these stalagmites to provide high-resolution regional paleoenvironmental information, and also data on SSTs and ENSO, variations in del-13C, UV-stimulated luminescence of humic and fulvic acids, particulate matter, petrography, layer thickness, inclusion frequency' and gray level along the growth axes of stalagmites will be related to regional rainfall and temperature, ocean SSTs, El Nino frequencies, and Southern Oscillation characteristics.