Unprecedented interannual variability of CH4 mole fractions and its driver over South Korea captured by integrated data in 2019
Samuel Takele Kenea, Innovative Meteorological Research Department, National Institute of Meteorological Sciences (NIMS), 33, Seohobuk-ro, Seogwipo-si, Jeju-do, 63568, Republic of Korea, samueltakele81@gmail.com (Presenter)
Haeyoung Lee, Innovative Meteorological Research Department, National Institute of Meteorological Sciences (NIMS), 33, Seohobuk-ro, Seogwipo-si, Jeju-do, 63568, Republic of Korea, leehy80@korea.kr
Sangwon Joo, Innovative Meteorological Research Department, National Institute of Meteorological Sciences (NIMS), 33, Seohobuk-ro, Seogwipo-si, Jeju-do, 63568, Republic of Korea, swjoo@korea.kr
Shanlan Li, Innovative Meteorological Research Department, National Institute of Meteorological Sciences (NIMS), 33, Seohobuk-ro, Seogwipo-si, Jeju-do, 63568, Republic of Korea, sunranlee@korea.kr
Lev D. Labzovskii, R&D Satellite and Observations Group,Royal Netherlands Meteorological Institute, (KNMI), 3731GA De Bilt, The Netherlands, labzowsky@gmail.com
Chu-Yong Chung, Innovative Meteorological Research Department, National Institute of Meteorological Sciences (NIMS), 33, Seohobuk-ro, Seogwipo-si, Jeju-do, 63568, Republic of Korea, cychung0530@korea.kr
Yeon-Hee Kim, Innovative Meteorological Research Department, National Institute of Meteorological Sciences (NIMS), 33, Seohobuk-ro, Seogwipo-si, Jeju-do, 63568, Republic of Korea, yeonheekim@korea.kr
Understanding the temporal variability of atmospheric CH4 mole fractions and its potential drivers can advance the progress toward mitigating changes to climate change. To comprehend interannual variability, spatial characteristics of anomalous CH4 mole fractions, and its drivers, we used integrated data from different platforms such as in-situ and satellites (TROPOMI and GOSAT) observations. A pronounced change of annual growth rate was detected at Anmyeondo (AMY), Republic of Korea, ranging of -27.9 to 33.2 ppb yr-1 and -1.9 to 18.0 ppb yr-1 as captured by in-situ and GOSAT, respectively. High growth rates were discerned in 2016 and 2019, 32-33 ppb yr-1 by in-situ and 16-18 ppb yr-1 by GOSAT, respectively. The high growth in 2016 was essentially explained by the strong El Niño events occurred in 2015-2016. Stable isotopic composition 13C/12C in CH4 collected by flask sampling at AMY during 2014-2019 were analyzed to infer the source signatures. The intercept of the Keeling plot for this period is -51.47‰, which suggests isotopic signature of biogenic emissions. The isotopic values in 2019 exhibited the strongest depletion, that implies an enhanced biogenic CH4 signal. Such changes of biogenic signal are affected by the variations of soil temperature and soil moisture. A large growth rate occurred in 2019 at AMY was induced by high soil temperature according to Noah Land Surface Model. This was extended to examine the spatial patterns of interannual variability of XCH4 over Korea were during April 2018 to December 2020 based on TROPOMI observations. The result indicated a spatial distribution of interannual variability, as well as the captured elevated anomaly over the southwest of the domain in autumn 2019, up to 70 ppb. Such variability was largely explained by the combined effect of soil temperature and soil moisture changes, indicating a pixel-wise correlation of XCH4 anomaly with those parameters is the range of 0.5 to 0.8 with a statistical significance (P<0.05). This implies that the soil-associated drivers are able to exert large-scale influence on regional distribution of CH4 in Korea. Finally, the result leads us to exert further effort to explicitly determine the contribution of climate variability to interannual variabilities in CH4 related to biogenic in the region.
Poster: Poster_Kenea__22_25.pdf
Presentation Type: Poster
Session: 4.2b Flux estimates and atmospheric inversions from space-based GHG measurements
Session Date: Thursday (6/17) 10:00 AM