CO2 Budget and Rectification Airborne Study--North America (COBRA--NA)

全球碳循环研究的动机是需要预测大气二氧化碳（CO2）的未来趋势，以确定陆地生物圈和海洋对不断变化的二氧化碳和气候的响应。目前，对海洋和陆地通量的最佳限制是通过逆分析得出的，逆分析利用生物地球化学和大气输送全球模型分析全球地表观测所得的二氧化碳和其他物种的浓度数据。目前逆研究的最大不确定性来源之一是CO2通量的季节性和日波动的“校正”，其中生物物理通量与输送速率之间的相关性在大气中产生了大规模、平稳的浓度梯度；此现象的验证数据目前不可用。本研究将提供精馏后CO2梯度的综合数据。这将通过在两个运动（夏季和冬季）中对北美和邻近海洋区域的行星边界层（PBL）内外的CO2、CO（一氧化碳）、SF6（六氟化硫）、13CO2和其他示踪剂的空中测量来完成，并辅以在选定区域的PBL内外的密集日观测。该项目由NSF、DOE、NASA和NOAA联合支持。

Studies of the global carbon cycle are motivated by the need to predict future trends in atmospheric carbon dioxide (CO2), to define responses of the terrestrial biosphere and oceans to changing CO2 and climate. Currently the best constraints on marine and terrestrial fluxes are derived by inverse analysis, where concentration data for CO2 and other species from global surface observations are analyzed using global models of biogeochemistry and atmospheric transport. One of the largest sources of uncertainty for current inverse studies is the "rectification" of seasonal and diurnal oscillations of CO2 fluxes, in which correlation between biophysical fluxes and rates for transport produce large scale, stationary concentration gradients in the atmosphere; validation data for this phenomenon are currently unavailable. This study will provide comprehensive data of the CO2 gradients due to rectification. This will be accomplished via airborne measurements of CO2, CO (carbon monoxide), SF6 (sulfur hexafluoride), 13CO2, and other tracers in and above the planetary boundary layer (PBL) over North America and adjacent ocean regions in two campaigns (summer and winter), supplemented by intensive diurnal observations in and above the PBL in selected regions. This project is supported jointly by NSF, DOE, NASA and NOAA.