Variations of Carbonyl Sulfide During the Dry/Wet Seasons Over the Amazon

• Published in: Geophysical research letters 2023-03, Vol.50 (5), p.n/a
• Main Authors: Wang, Xinyue, Jiang, Xun, Li, King‐Fai, Liang, Mao‐Chang, Kuai, Le, Tan, Lin, Yung, Yuk L.
• Format: Article
• Language: English
• Subjects: Aircraft; Amazon rainforest; Anomalies; Atmosphere; Biomass; Biomass burning; Carbon; Carbonyl compounds; Carbonyl sulfide; Carbonyls; Chemistry; chemistry‐transport model; Dry season; Fourier transforms; Photosynthesis; Photosynthetic activity; Precipitation; Rainforests; Rainy season; Satellites; Seasons; Stratosphere; Sulfides; Sulphides; TES mid‐tropospheric OCS; Troposphere; Vegetation; Wet season; Wind
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2022GL101717

Mid‐tropospheric Carbonyl sulfide (OCS) retrievals from the Tropospheric Emission Spectrometer (TES) are utilized to study OCS distributions during the dry/wet seasons over the Amazon rainforest. TES OCS retrievals reveal positive OCS anomalies (∼16 ppt) over the central and southern parts of the Amazon during August–October (dry season) compared to January–March (wet season). There is less OCS taken up by vegetation and soil and more OCS released from biomass burning during the dry season, which causes an increase in OCS concentrations. Strong sinking air during the dry season also helps to trap OCS and this contributes to positive OCS anomalies. MOZART‐4 model captures positive OCS anomalies over the central and southern regions of the Amazon and negative OCS anomalies over the northern part of the Amazon, which are similar to those from TES mid‐tropospheric OCS retrievals. Our studies can help us better understand OCS variations and photosynthetic activities. Plain Language Summary As a photosynthetic tracer, OCS can help us better understand photosynthetic activities, the biosphere‐atmosphere interaction, and the carbon sink. There are positive OCS anomalies (∼16 ppt) over the central and southern parts of the Amazon during August–October (dry season), which is related to reduced OCS uptake from vegetation and soil, enhanced OCS emission from biomass burning, and strengthened sinking air. MOZART‐4 is used to simulate the OCS variations during dry/wet seasons. Model results are similar to those from Tropospheric Emission Spectrometer OCS retrievals. However, there are some differences between the spatial distributions of OCS in the MOZART‐4 model and the satellite retrievals. Results in this study can help us better understand the variability of OCS and photosynthetic activities over the Amazon rainforest, which is the biggest rainforest and one of the largest sinks of OCS. Key Points Tropospheric Emission Spectrometer OCS concentrations are higher over the central and southern parts of the Amazon during the dry season than the wet season High OCS concentrations are related to reduced vegetation uptake, enhanced biomass burning, and increased sinking air MOZART‐4 captures the observed positive OCS anomalies over the central and southern Amazon during August–October (dry season)