Revisiting the Estimate of the North Sea Air‐Sea Flux of CO2 in 2001/2002: The Dominant Role of Different Wind Data Products
Revisiting the Estimate of the North Sea Air‐Sea Flux of CO2 in 2001/2002: The Dominant Role of Different Wind Data Products
复制标题
重新审视 2001/2002 年北海海气通量估算：不同风数据产品的主导作用
DOI：
10.1029/2017jg004281
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
H. Thomas
中科院分区：
文献类型：
--
作者：
Maybritt Meyer;J. Pätsch;B. Geyer;H. Thomas
对于北海，北大西洋东北部的半封闭陆架海，在早期的工作中估计了2001年和2002年的季节和年度CO2海气通量（ASF）。基础观测、ΔpCO2、盐度和温度与ERA40再分析得出的6小时风数据相结合。为了评估不同风数据产品对CO2 ASF计算的影响，我们将ERA40风数据与来自非静力区域气候模式COSMO‐CLM的coastDat数据进行了比较。从9月、11月、2月和5月的四个观测月份来看，除了5月的数据外，所有数据都显示coastDat的风速高于ERA40，特别是在挪威、英国和大陆海岸。最大的差异发生在北方近海地区。与观测到的风数据的比较一般支持这一特点：在Helgoland，在德国湾的一个岛屿，在比利时桩“Westhinder”的ERA40数据低估，coastDat数据和观察。挪威北海两个平台的风观测数据可用：在挪威海岸外的北方“Troll”站，数据高估了冬季的观测数据。在北海中部的Ekofisk，ERA40数据与观测结果吻合良好，而coastDat数据在除5月外的所有月份都略高估了观测数据。相应的CO2 ASF估计显示出挪威海岸外最强的偏差。使用不同的散装公式来确定净年ASF，由于不同的风产品导致高达34%的差异。
For the North Sea, a semienclosed shelf sea in the northeastern North Atlantic, the seasonal and annual CO2 air‐sea fluxes (ASF) had been estimated for 2001 and 2002 in earlier work. The underlying observations, ΔpCO2, salinity, and temperature had been combined with 6‐hourly wind data derived from ERA40 reanalysis. In order to assess the impact of different wind data products on the computation of CO2 ASF, we compared ERA40 wind data with coastDat data derived from the nonhydrostatic regional climate model COSMO‐CLM. From the four observational months September, November, February, and May all but the May data show higher wind speeds for coastDat than for ERA40, especially off the Norwegian, UK, and continental coasts. Largest differences occur in the northern offshore areas. The comparison with observed wind data supports this feature generally: At Helgoland, an island in the German Bight, and at the Belgium pile “Westhinder” the ERA40 data underestimate both, the coastDat data and the observations. Wind observations for two Norwegian North Sea platforms were available: At the northern station “Troll” off the Norwegian coast the coastDat data overestimate the observations in winter. At “Ekofisk” in the central North Sea the ERA40 data fit the observations well, while the coastDat data slightly overestimate the observational data in all months but in May. The corresponding CO2 ASF estimates show strongest deviations off the Norwegian coast. Using different bulk formulas for determining the net annual ASF resulted in differences due to different wind products of up to 34%.