Late glacial-Holocene record of Southern Hemisphere westerly wind dynamics from the Falkland Islands, South Atlantic Ocean
Late glacial-Holocene record of Southern Hemisphere westerly wind dynamics from the Falkland Islands, South Atlantic Ocean
复制标题
南大西洋福克兰群岛南半球西风动力学的晚冰期-全新世记录
作者：
Monteath A
南半球西风带是南半球中纬度气候的一个重要特征，与南大洋CO2的封存和释放密切相关。这条风带过去的强度和位置变化很难解决，特别是在更新世-全新世过渡时期，这一时期与大气温度和CO2水平的波动有关。我们使用灰尘地球化学，粒度测量，和古生态分析，从泥炭序列在福克兰群岛，南大西洋，描述的变化在SHWW之间的16.0和6.5万年（CE 1950年前的几千年）。在南极寒冻期（ACR，14.9-13.0 ka）之前和期间，~51°S处的风强度较低，在13.1 ~ 12.1 ka期间随着气温的升高而增强，然后减弱，在早全新世热峰期（12.1 ~ 10.9 ka）达到最小值。从12.0到10.2ka，西北气流变得更加占主导地位，风力强度一直很低，直到我们的记录受到风暴潮或海啸的影响。7.8 ka.这些数据表明，在南纬的SHWW，从北51°S之前和在ACR期间，在~51°S的全新世开始之前，和南部的51°S在全新世早期热最大。这种模式表明，通过更新世-全新世过渡的SHWW的纬度与大气温度耦合。
The Southern Hemisphere westerly wind belt (SHWW) is a major feature of Southern Hemisphere, midlatitude climate that is closely linked with the sequestration and release of CO2in the Southern Ocean. Past changes in the strength and position of this wind belt are poorly resolved, particularly across the Pleistocene-Holocene transition, a time period associated with fluctuations in atmospheric temperatures and CO2levels. We used dust geochemistry, particle size measurements, and paleoecological analyses from a peat sequence in the Falkland Islands, South Atlantic Ocean, to describe changes in the SHWW between 16.0 and 6.5 ka (thousands of years before CE 1950). Wind strength was low at ~51°S before and during the Antarctic Cold Reversal (ACR, 14.9–13.0 ka), intensified between 13.1 and 12.1 ka as atmospheric temperatures increased, and then weakened, reaching a minimum between 12.1 and 10.9 ka during the Early Holocene thermal maximum. Northwesterly air masses became more dominant from 12.0 to 10.2 ka, and wind strength remained low until our record was affected by a storm surge or tsunami ca. 7.8 ka. These data indicate a southward shift in the latitude of the SHWW, from north of 51°S prior to and during the ACR, at ~51°S before the onset of the Holocene, and south of 51°S during the early Holocene thermal maximum. This pattern suggests that the latitude of the SHWW was coupled with atmospheric temperatures through the Pleistocene-Holocene transition.