Annual carbon dioxide drawdown and the Northern Annular Mode
Annual carbon dioxide drawdown and the Northern Annular Mode
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年度二氧化碳减少和北部环形模式
DOI：
10.1029/2003gb002044
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发表时间：
2004
影响因子：
5.2
通讯作者：
J. Wallace
中科院分区：
文献类型：
--
作者：
J. Russell;J. Wallace
将夏季北方半球大气二氧化碳（CO2）下降的逐年变化与海平面气压（SLP）、地表气温和陆地植被生产力（由卫星导出的归一化植被指数（NDVI）推断）的相应逐年变化进行比较。1980-2000年的CO2下降的年值估计平滑的时间序列直接来自个人烧瓶样品在北方半球监测站最连续的记录。领先的主成分的9个标准化的下降时间序列，其中所有站表现出积极的负载，是用来代表半球信号的CO2下降。线性回归分析被用来推断海平面气压，地面气温和在不同季节的年，其中下降是非常强烈的观测到的NDVI异常的空间格局。冬季之前的异常高水位下降季节表现出的模式的特点，高指数的北方环形模式（NAM）。SLP在北极地区往往非常低，在中纬度地区往往很高，欧亚大陆往往非常温暖。在生长季节的前几个月里，在降水量非常高的年份里观察到的NDVI模式表明欧亚大陆的生产力很高。这些结果支持的概念，冬季NAM的影响，通过调节冬季温度，反过来影响在随后的生长季节的陆地生物圈的生产力的CO2的年度下降。
Year‐to‐year variations in summer drawdown of Northern Hemisphere atmospheric carbon dioxide (CO2) are compared with corresponding year‐to‐year variations in sea‐level pressure (SLP), surface air temperature, and the productivity of land vegetation as inferred from the satellite‐derived normalized difference vegetation index (NDVI). Annual values of CO2 drawdown for the years 1980–2000 are estimated from smoothed time series derived directly from individual flask samples at the nine Northern Hemisphere monitoring stations with the most continuous records. The leading principal component of the nine standardized drawdown time series, in which all stations exhibit positive loadings, is used to represent the hemispheric signal in the CO2 drawdown. Linear regression analysis is used to infer the spatial patterns of anomalies in sea‐level pressure, surface air temperature, and the NDVI observed during various seasons of years in which the drawdown is anomalously strong. Winters preceding anomalously high drawdown seasons exhibit patterns characteristic of the high index of the Northern Annular Mode (NAM). SLP tends to be anomalously low over the Arctic and high over midlatitudes, and Eurasia tends to be anomalously warm. The pattern of the NDVI observed during the early months of the growing season in years with anomalously high drawdown is indicative of high productivity over Eurasia. These results support the notion that the wintertime NAM influences the annual drawdown of CO2 by modulating winter temperatures that, in turn, affect the productivity of the terrestrial biosphere during the subsequent growing season.