The influence of precipitation origin on the δ18O–T relationship at Neumayer station, Ekstrmisen, Antarctica
The influence of precipitation origin on the δ18O–T relationship at Neumayer station, Ekstrmisen, Antarctica
复制标题
南极洲埃克斯特米森 Neumayer 站降水来源对 δ18O-T 关系的影响
作者：
E. Schlosser;C. Reijmer;H. Oerter;W. Graf
摘要利用1981-2000年南极埃克斯特米森诺伊迈尔站的新鲜雪样，研究了δ 18 O与气温的关系。用一个计算了5天后向轨迹的轨迹模式研究了不同天气形势和不同水汽源对这种相关性的影响。大气温度与δ 18 O的相关性较好，但δ 18 O-T关系的质量随轨迹类型的不同而不同。此外，还考虑了海冰对湿空气传播路径的影响。弹道下方的开阔海水量对δ 18 O-T关系有很大的影响。对于完全在开放水域之上的轨迹，没有发现δ 18 O和T之间的显著相关性，因为与含有额外蒸发的海洋水蒸气的空气混合会影响降水的同位素比。然而，在完全被冰覆盖的威德尔海上空发现了一个非常高的相关性。
Abstract The relationship between δ18O and air temperature at Neumayer station, Ekstrmisen, Antarctica, was investigated using fresh-snow samples from the time period 1981–2000. A trajectory model that calculated 5 day-backward trajectories was used to study the influence of different synoptic weather situations and thus of different moisture sources on this correlation. Generally a high correlation between air temperature and δ18O was found, but the quality of the δ18O–T relationship varied with the different trajectory classes. Additionally, the sea-ice coverage on the travel path of the moist air was considered. The amount of open ocean water underneath the trajectory has a large influence on the δ18O–T relationship. For trajectories that lead completely above open water, no significant correlation between δ18O and T was found, because mixing with air masses containing additionally evaporated water vapour from the ocean influences the isotope ratio of precipitation. A very high correlation, however, was found for transports over the completely ice-covered Weddell Sea.