Japan Geoscience Union Meeting 2015

Presentation information


Symbol A (Atmospheric and Hydrospheric Sciences) » A-AS Atmospheric Sciences, Meteorology & Atmospheric Environment

[A-AS21] Atmospheric Chemistry

Wed. May 27, 2015 6:15 PM - 7:30 PM Convention Hall (2F)

Convener:*Yousuke Sawa(Oceanography and Geochemistry Research Department, Meteorological Research Institute), Nobuyuki Takegawa(Graduate School of Science and Engineering, Tokyo Metropolitan University), Yugo Kanaya(Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology), Kenshi Takahashi(Research Institute for Sustainable Humanosphere, Kyoto University), Hiroshi Tanimoto(National Institute for Environmental Studies)

6:15 PM - 7:30 PM

[AAS21-P24] Climatology of spatiotemporal variations of tropospheric CO2 observed by CONTRAIL-CME

*Taku UMEZAWA1, Toshinobu MACHIDA1, Yousuke SAWA2, Hidekazu MATSUEDA2, Yosuke NIWA2 (1.National Institute for Environmental Studies, 2.Meteorological Research Insitute)

CONTRAIL is the ongoing project that measures atmospheric trace gases during intercontinental flights of Japan Airlines. Atmospheric CO2 concentration is analyzed using Continuous CO2 Measuring Equipment (CME) onboard the aircraft. From ~20 thousands of measurement flights since 2005, extensive number of CO2 data (~2 millions) along level-flight and ascent/descent tracks have been obtained, enabling us to well characterize spatiotemporal distributions of atmospheric CO2 covering large part of the globe especially the Asia-Pacific regions. In this study, we define ∆CO2 as a deviation from the long-term trend observed at a northern hemispheric baseline station Mauna Loa, Hawaii, to illustrate climatological CO2 distributions including seasonal and shorter-term variations. For instance, over airports in Japan, ∆CO2 reaches seasonal maximum at the end of April with higher values near the surface. In this season, high ∆CO2 spreads east of the Asian continent in the upper troposphere over the northern Pacific. In contrast, seasonal minimum of ∆CO2 occurs in September with more depletion in the upper troposphere. The summertime low ∆CO2 in the upper troposphere appears to be more pronounced over the Asian continent than over the Pacific. Likewise, we present seasonal variations of vertical profiles of tropospheric ∆CO2 over various airports and of spatial distributions in the upper troposphere in large-scale perspective, and discuss them from viewpoints of seasonally varying continental sources/sinks and atmospheric transport.