Atmospheric potential oxygen: New observations and their implications for some atmospheric and oceanic models
Atmospheric potential oxygen: New observations and their implications for some atmospheric and oceanic models
复制标题
大气势氧：新观测及其对某些大气和海洋模型的影响
DOI：
--
复制
发表时间：
2006
期刊：
影响因子：
--
通讯作者：
B. Paplawsky
中科院分区：
文献类型：
--
作者：
M. Battle;S. M. Fletcher;M. Bender;R. Keeling;A. Manning;N. Gruber;P. Tans;M. Hendricks;D. T. Ho;C. Simonds;R. Mika;B. Paplawsky
对大气中O2/N2比率和CO2浓度的测量可以结合成一种被称为大气潜氧（APO/N2 + CO2）的示踪剂，这种示踪剂相对于陆地生物活动是保守的。因此，APO主要反映海洋地球化学和大气环流。在Stephens等人（1998）工作的基础上，我们提供了一组1996-2003年的APO观测，其空间覆盖范围前所未有。结合普林斯顿和斯克里普斯空气采样计划的数据，数据集包括从低纬度太平洋的船只收集的新观测数据。数据显示，与过去的研究中观察到的相比，半球间的APO梯度较小，并且半球内的结构不同。这些差异似乎主要是由于载脂蛋白场随时间的真实的变化。数据还显示，在赤道附近的APO显着的最大值。遵循Gruber等人（2001）的方法，我们将这些观测结果与海洋O2和CO2通量场产生的APO预测以及大气传输的前向模型进行了比较。我们的模型预测与早期的建模研究不同，主要反映了大气传输模型（本研究中的TM 3）的选择。模型的预测显示一般良好的协议与观测，匹配的大小的半球间梯度，赤道最大的近似振幅和范围，和振幅和定相的季节性APO周期在大多数站。仍有改进的余地。半球间梯度的一致性似乎是巧合;在过去的十年中，真实的APO梯度已经发展到与我们的时间无关模型一致的值。此外，赤道最大值在数据中比模型中更明显。这可能是由于过于剧烈的模式传输，或在我们的建模工作中使用的海气通量的空间分辨率不足。最后，大气传输模型预测的季节性周期表明，阿留申群岛的季节性整流器过多，其他地方的问题较小。
Measurements of atmospheric O2/N2 ratios and CO2 concentrations can be combined into a tracer known as atmospheric potential oxygen (APO ≈ O2/N2 + CO2) that is conservative with respect to terrestrial biological activity. Consequently, APO reflects primarily ocean biogeochemistry and atmospheric circulation. Building on the work of Stephens et al. (1998), we present a set of APO observations for the years 1996–2003 with unprecedented spatial coverage. Combining data from the Princeton and Scripps air sampling programs, the data set includes new observations collected from ships in the low‐latitude Pacific. The data show a smaller interhemispheric APO gradient than was observed in past studies, and different structure within the hemispheres. These differences appear to be due primarily to real changes in the APO field over time. The data also show a significant maximum in APO near the equator. Following the approach of Gruber et al. (2001), we compare these observations with predictions of APO generated from ocean O2 and CO2 flux fields and forward models of atmospheric transport. Our model predictions differ from those of earlier modeling studies, reflecting primarily the choice of atmospheric transport model (TM3 in this study). The model predictions show generally good agreement with the observations, matching the size of the interhemispheric gradient, the approximate amplitude and extent of the equatorial maximum, and the amplitude and phasing of the seasonal APO cycle at most stations. Room for improvement remains. The agreement in the interhemispheric gradient appears to be coincidental; over the last decade, the true APO gradient has evolved to a value that is consistent with our time‐independent model. In addition, the equatorial maximum is somewhat more pronounced in the data than the model. This may be due to overly vigorous model transport, or insufficient spatial resolution in the air‐sea fluxes used in our modeling effort. Finally, the seasonal cycles predicted by the model of atmospheric transport show evidence of an excessive seasonal rectifier in the Aleutian Islands and smaller problems elsewhere.