Kyushu University · Physics and Astronomy
Professor Masaru Kogure's research lab specializes in atmospheric and aeronomical sciences, focusing on gravity wave dynamics, atmospheric tides, and thermospheric responses to climate change. The lab investigates wave-atmosphere interactions using ground-based lidar, satellite observations (e.g., AIRS, CIPS, VIIRS), and high-resolution numerical modeling (e.g., GAIA, MERRA-2, GEOS-5 FP). Key research directions include the modulation of gravity waves by large-scale wind systems such as the polar night jet, stratospheric sudden warming events, and the impact of climate forcings like ENSO and CO₂ doubling on the upper atmosphere. The lab also explores wave-induced energy and momentum transport in the mesosphere, lower thermosphere, and thermosphere, contributing to improved understanding of atmospheric coupling processes.
Figures are computed from collected data and may differ slightly.
Abstract A mountain wave with a significant brightness temperature amplitude and ~500 km horizontal wavelength was observed over the Andes on 24–25 July 2017 in Atmospheric Infrared Sounder (AIRS)/Aqua satellite data. In the Modern‐Era Retrospective Analysis for Research and Applications, version 2 (MERRA‐2), reanalysis data, the intense eastward wind flowed over the Andes. Visible/Infrared Imaging Radiometer Suite (VIIRS)/Suomi‐NPP (National Polar‐orbiting Partnership) did not detect the mounta
Abstract Ground‐based and satellite observations have shown that the tidal component DW1 in the equatorial mesosphere and lower thermosphere (MLT) was enhanced in July–October 2015, which was an intense El Niño year. This enhancement is reproduced in the 21 years reanalysis‐driven model simulation by the Ground‐to‐topside model of Atmosphere and Ionosphere for Aeronomy (GAIA). Our analysis shows the (1,1) Hough mode dominates this tidal enhancement, and its peak amplitude was 7.4 K (74%) higher
Abstract Nightly mean potential energy of gravity waves (GWs) per unit mass ( E p ) over Syowa Station (69 ° S, 40 ° E) was calculated from temperature profiles observed by the Rayleigh/Raman lidar from 2011 to 2015. The E p values in the upper stratosphere and lower mesosphere were significantly enhanced on 8–21 August 2014, except on 12 August. A ray‐tracing analysis showed that large‐scale GWs emitted from various latitudes could be refracted and forced to converge above Syowa due to the pole
Abstract A rare Antarctic stratospheric sudden warming (SSW) occurred on August 30, 2019, and was a minor warming event. We investigated variations in gravity wave (GW) activity before and after this Antarctic SSW event using two satellite measurements (AIRS and CIPS) and reanalysis data (GEOS‐5 FP). GW activity over the Andes decreased after August 30, although the westerly wind was 40–60 ms −1 and cannot filter out GWs with small zonal phase speed. This decline over the Andes was probably caus
Abstract We explored mechanisms for the thermospheric zonal mean wind responses to doubled CO 2 concentration through investigating the zonal mean momentum balance in the thermosphere using GAIA model simulations in June. The analysis shows that ion drag, molecular viscosity, and meridional pressure gradient force vary 3–20 times more than the other forces due to the doubled CO 2 concentration. The three forces strongly attenuate each other; consequently, the increase in zonal mean zonal ion dra
Abstract The potential energy of gravity waves (GWs) per unit mass ( E p ), at altitudes of 15–70 km, has been examined from temperature profiles obtained by a Rayleigh/Raman lidar at Syowa Station (69°S, 40°E) from May 2011 to October 2013, with the exception of the summer months. The GWs with ground‐based wave periods longer than 2 h and vertical wavelengths between 1.8 and 16 km were extracted from the temperature profiles. E p was larger in winter than in spring and fall, although in 2012, a
Abstract. We developed user-friendly software based on Matsuda et al.'s (2014) 3D-FFT method (Matsuda-transform, M-transform) for airglow imaging data analysis as a function of Interactive Data Language (IDL). Users can customize the range of wave parameters to process when executing the program. The input for this function is a 3-D array of a time series of a 2-D airglow image in geographical coordinates. We applied this new function to mesospheric airglow imaging data with slightly different o
Abstract To assess the impacts of the tropospheric ozone modulation due to El Niño on tides, we performed two simulations by using the Ground‐to‐topside Atmosphere Ionosphere model for Aeronomy model: zonally symmetric ozone density and longitudinal ozone variation of an El Niño pattern. Our results show that the ozone modulation strengthens (attenuates) the first symmetric mode of the DW2 (D0 and DW1) tide by ∼+5% (∼−1% and ∼−4%) from ∼20 to ∼100 km altitudes on average. These responses are pro
Abstract Mesospheric gravity‐wave (GW) phase velocity spectra and total powers at two Antarctic stations, Davis and Syowa, were derived using OH airglow data from March to October in 2016. The total powers have similar seasonal variation, that is, maxima in winter at both stations. The average powers at both stations in winter were not significantly different. However, the power at Davis in September was three times smaller than that at Syowa. This lower power at Davis was attributed to GWs with
Earth and Space Science Open Archive This preprint has been submitted to and is under consideration at Journal of Geophysical Research - Atmospheres. ESSOAr is a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v1]Characteristics of gravity wave horizontal phase velocity spectra in the mesosphere over the Antarctic stations, Syowa and Davis.AuthorsMasaruKogureiDNakamu
Earth and Space Science Open Archive This preprint has been submitted to and is under consideration at Geophysical Research Letters. ESSOAr is a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v2]Gravity Wave Weakening During the 2019 Antarctic Stratospheric Sudden WarmingAuthorsMasaruKogureiDJiaYueHuixinLiuSee all authors Masaru KogureiDCorresponding Author• Submitt
Abstract This study examines the seasonal distributions of simultaneous stratospheric concentric gravity waves (GWs) observed by the Atmospheric Infrared Sounders and concentric traveling ionospheric disturbances (TIDs) detected by the ground‐based Global Navigation Satellite System Total Electron Content observations over the U.S. in 2022, to illustrate the mesoscale vertical coupling between the lower atmosphere and the ionosphere. We compared epicenters of GWs and TIDs in the stratosphere and
This dataset contains forces, advections, and winds output from the GAIA model, that are related to the Figures in the paper. The forces and advections are divided by the Coriolis parameter or a zonal mean absolute vorticity.
From August 11th, 2021, humid air flowed into Kyushu, the western part of Japan’s main islands, intensifying a stationary front and leading to record-breaking precipitation. Around 17 UT on August 12th, 2021, a satellite observation (AIRS) captured concentric stratospheric gravity waves (GWs) over the heavy rainfall. ~6 hours later, Japan and Korea’s GNSS networks detected medium-scale traveling ionospheric disturbances (MSTIDs) likely propagating from Kyushu (~131 E, ~32.5 N) in directins from
Open papers in the app to read, cite, and organize with AI.
