Interpreting temporal changes of atmospheric CO₂ over fire affected regions based on GOSAT observations

著者

Shi Y., Matsunaga T., Noda H.

雑誌名

IEEE Geoscience and Remote Sensing Letters, 14(1), 77-81

DOI

10.1109/LGRS.2016.2627056

概要

The carbon dioxide (CO₂) emissions released from biomass burning significantly affect the temporal variations of atmospheric CO₂ concentrations. Based on a long-term (July 2009–June 2015) retrieved data sets by the greenhouse gases observing satellite (GOSAT), the seasonal cycle and interannual variations of column-averaged volume mixing ratios of atmospheric carbon dioxide (XCO₂) in four fire affected continental regions were analyzed. The results showed that Northern Africa (NA) had the largest seasonal variations after removing its regional trend of XCO₂ with peak-to-peak amplitude of 6.2 ppm within the year, higher than central South America (CSA) (2.4 ppm), Southern Africa (SA) (3.8 ppm), and Australia (1.7 ppm). The detrended regional XCO₂ (ΔXCO₂) was found to be positively correlated with the fire CO₂ emissions during the fire activity period but with different seasonal variabilities. NA recorded the largest change of seasonal variations of ΔXCO₂ with a total of 12.8 ppm during fire seasons, higher than CSA, SA, and Australia with 5.4, 6.7, and 2.2 ppm, respectively. During the fire episode, the positive ΔXCO₂ was noticed during June–November in CSA, December to next June in NA, and May–November in SA. The Pearson correlation coefficients between the variations of ΔXCO₂ and fire CO₂ emissions achieved the best correlations in SA (R = 0.77 and p < 0.05 ). This letter revealed that fire CO₂ emissions and GOSAT XCO₂ presented consistent seasonal variations.