| Autor: |
Feldman, Andrew F., Zhang, Zhen, Yoshida, Yasuko, Chatterjee, Abhishek, Poulter, Benjamin |
| Předmět: |
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| Zdroj: |
Atmospheric Chemistry & Physics; 2023, Vol. 23 Issue 2, p1545-1563, 19p |
| Abstrakt: |
The global carbon cycle is experiencing continued perturbations via increases in atmospheric carbon concentrations, which are partly reduced by terrestrial biosphere and ocean carbon uptake. Greenhouse gas satellites have been shown to be useful in retrieving atmospheric carbon concentrations and observing surface and atmospheric CO 2 seasonal-to-interannual variations. However, limited attention has been placed on using satellite column CO 2 retrievals to evaluate surface CO 2 fluxes from the terrestrial biosphere without advanced inversion models at low latency. Such applications could be useful to monitor, in near real time, biosphere carbon fluxes during climatic anomalies like drought, heatwaves, and floods, before more complex terrestrial biosphere model outputs and/or advanced inversion modelling estimates become available. Here, we explore the ability of Orbiting Carbon Observatory-2 (OCO-2) column-averaged dry air CO 2 (XCO 2) retrievals to directly detect and estimate terrestrial biosphere CO 2 flux anomalies using a simple mass-balance approach. An initial global analysis of surface–atmospheric CO 2 coupling and transport conditions reveals that the western US, among a handful of other regions, is a feasible candidate for using XCO 2 for detecting terrestrial biosphere CO 2 flux anomalies. Using the CarbonTracker model reanalysis as a test bed, we first demonstrate that a well-established mass-balance approach can estimate monthly surface CO 2 flux anomalies from XCO 2 enhancements in the western United States. The method is optimal when the study domain is spatially extensive enough to account for atmospheric mixing and has favorable advection conditions with contributions primarily from one background region. We find that errors in individual soundings reduce the ability of OCO-2 XCO 2 to estimate more frequent, smaller surface CO 2 flux anomalies. However, we find that OCO-2 XCO 2 can often detect and estimate large surface flux anomalies that leave an imprint on the atmospheric CO 2 concentration anomalies beyond the retrieval error/uncertainty associated with the observations. OCO-2 can thus be useful for low-latency monitoring of the monthly timing and magnitude of extreme regional terrestrial biosphere carbon anomalies. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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