Japan Geoscience Union Meeting 2025

Presentation information

[E] Oral

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

[A-AS06] Atmospheric (Stratosphere-troposphere) Processes And their Role in Climate

Tue. May 27, 2025 9:00 AM - 10:30 AM 105 (International Conference Hall, Makuhari Messe)

convener:Shunsuke Noguchi(Department of Earth and Planetary Sciences, Faculty of Science, Kyushu University), Yayoi Harada(Meteorological Research Institute), Kazuaki Nishii(Graduate School of Bioresources, Mie University), Nawo Eguchi(Research Institute for Applied Mechanics, Kyushu University), Chairperson:Shunsuke Noguchi(Department of Earth and Planetary Sciences, Faculty of Science, Kyushu University), Yayoi Harada(Meteorological Research Institute)



9:00 AM - 9:20 AM

[AAS06-01] The JAGUAR-DAS whole neutral atmosphere reanalysis: JAWARA

★Invited Papers

*Dai Koshin1,2, Kaoru Sato3, Shingo Watanabe4, Kazuyuki Miyazaki5 (1.Japan Society for the Promotion of Science Overseas Research Fellow, 2.High Altitude Observatory, NSF National Center for Atmospheric Research, 3.Department of Earth and Planetary Science, The University of Tokyo, 4.Japan Agency for Marine-Earth Science and Technology, 5.Jet Propulsion Laboratory, California Institute of Technology)


Keywords:Reanalysis, Middle atmosphere, Neutral atmosphere, Data assimilation, Satellite

Using the Japanese Atmospheric General circulation model for the Upper Atmosphere Research-Data Assimilation System (JAGUAR-DAS), a whole neutral atmosphere reanalysis dataset (JAWARA) over about 19 years from September 2004 to December 2023 is produced. JAWARA is the first long-period reanalysis covering the height region from the surface to the lower thermosphere (~ 110 km). This wide height coverage is a notable advantage over other operational reanalysis datasets, which cover up to the middle mesosphere.
Key dynamical characteristics are compared between JAWARA and two satellite observations and three other operational reanalysis datasets in their covered height regions. The seasonal variations of zonal mean temperature and zonal wind are similar between JAWARA and the datasets used for comparison. The climatologies of zonal mean temperature, zonal wind, residual-mean circulation, and E-P flux in the meridional cross section are also broadly consistent with other reanalysis datasets. The analyzed residual-mean vertical flow in the northern high latitudes in the middle atmosphere exhibits the well-known patterns of upwelling in summer and downwelling in winter. JAWARA also shows a prominent feature of strong downward propagating anomalies from the lower thermosphere to the upper stratosphere after sudden stratospheric warmings.
This analysis takes full advantage of the JAWARA data, which cannot be made using satellite observations and other reanalysis datasets. This reanalysis product is expected to contribute broadly to future research on the characteristics of observed mesospheric phenomena, thermosphere-ionosphere coupling, space weather, and improvement of middle atmospheric meteorological systems, including their interannual and decadal scale variability.

This work has been published to PEPS (Koshin et al., 2025; https://doi.org/10.1186/s40645-024-00674-3) and the JAWARA dataset is available online: https://doi.org/10.17592/002.2025010407