A5017217363- Atmospheric Ozone and Climate
- Atmospheric chemistry and aerosols
- Meteorological Phenomena and Simulations
- Climate variability and models
- Atmospheric aerosols and clouds
- Atmospheric and Environmental Gas Dynamics
- Ionosphere and magnetosphere dynamics
- Precipitation Measurement and Analysis
- Oceanographic and Atmospheric Processes
- Geophysics and Gravity Measurements
- Inertial Sensor and Navigation
- Fire effects on ecosystems
- Aeolian processes and effects
- Ocean Waves and Remote Sensing
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Tropical and Extratropical Cyclones Research
- Impact of Light on Environment and Health
- Ocean Acidification Effects and Responses
- Remote Sensing and Land Use
- Remote Sensing in Agriculture
- GNSS positioning and interference
- Metal-Catalyzed Oxygenation Mechanisms
- Nerve injury and regeneration
- Marine and coastal ecosystems
Fukuoka University
2013-2025
Kyoto University
2005-2019
Osaka City University
2019
Graduate School USA
2019
Planetary Science Institute
2002
Prevention Institute
1995
A polarization lidar was continuously operated aboard the research vessel Mirai in tropical western Pacific over three northern winters: at 2.0°N, 138.0°E during November and December 2001; 138.5°E 2002; 7.5°N, 134.0°E 2004 January 2005. Intensive radiosonde soundings were made from 3‐h intervals all campaigns. The mechanisms that underlie observed variations cirrus tropopause layer (TTL) are discussed viewpoint of large‐scale dynamics transport. During 2001 campaign, region cold, but TTL...
Bromoform (CHBr 3 ), dibromochloromethane 2 Cl), and dibromomethane (CH Br ) in the atmosphere were measured at various sites, including tropical islands, Arctic, open Pacific Ocean. Up to 40 ppt of bromoform was observed along coasts islands under a sea breeze. Polybromomethane concentrations highly correlated among coastal samples, ratios CH /CHBr CHBr Cl/CHBr showed clear tendency decrease with increasing concentration. These findings are consistent observations that polybromomethanes...
We investigated water vapor variations in the tropical lower stratosphere on seasonal, quasi‐biennial oscillation (QBO), and decadal time scales using balloon‐borne cryogenic frost point hygrometer data taken between 1993 2009 during various campaigns including Central Equatorial Pacific Experiment (March 1993), once or twice annually Soundings of Ozone Water Region (SOWER) project eastern (1998–2003) western Southeast Asia (2001–2009), Ticosonde regular sounding at Costa Rica (2005–2009)....
Balloon‐borne observations of frost‐point temperature and ozone in the equatorial western, central eastern Pacific as well over Brazil provide a highly accurate data set water vapor across tropical tropopause. Data were obtained at San Cristóbal, Galapagos, Ecuador (0.9°S, 89.6°W), during late northern winter summer 1998 1999 Juazeiro do Norte, (7.2°S, 39.3°W), February November 1997. Earlier western region March 1993 reanalyzed to extend scope observations. The show three different...
Abstract Lookup tables for estimating the cloud-top height and visible optical thickness of upper-tropospheric clouds by infrared brightness temperature TB at 10.8 μm (T11) its difference from 12 (ΔT11–12) measured a geostationary satellite are presented. These lookup were constructed regressing cloud radar measurements CloudSat over Japanese multifunctional transport MTSAT-1R. Standard deviations around estimates also displayed as an indicator ambiguity in estimates. For with T11 <...
Abstract We investigate the influence of background wind regime on interannual variability in equatorial Kelvin waves (including both freely propagating ones and convectively coupled ones) upper troposphere lower stratosphere using ERA5 re-analysis data. focus number wave cases as a function westerly that controls propagation, given by zonal index (ZWI) eastern Pacific is measure strength branch Walker circulation western hemisphere. The ZWI correlates well with sea surface temperature...
Soundings of frost‐point hygrometers, ozonesondes, and radiosondes at San Cristóbal Island (0.9°S, 89.6°W) in September 1998 provide an observational evidence that equatorial Kelvin waves around the tropopause act as a dehydration pump for stratosphere. During downward‐displacement phase wave, dry ozone‐rich stratospheric air is transported into upper troposphere. upward‐displacement phase, on other hand, higher specific‐humidity moves up region, but same time, this upward motion causes...
Here we present measurements of a range carbon‐based compounds: carbon dioxide (CO 2 ), monoxide (CO), methane (CH 4 nonmethane hydrocarbons (NMHCs), methyl halides, and dimethyl sulfide (DMS) emitted by Australian savanna fires studied as part the Biomass Burning Lightning Experiment (BIBLE) phase B aircraft campaign, which took place during local late dry season (28 August to 13 September 1999). Significant enhancements short‐lived NMHCs were observed in boundary layer (BL) over region...
Using the very high frequency (46.5 MHz) middle and upper atmosphere radar (MUR), Ka band (35 GHz) X (9.8 weather radars, a Kelvin‐Helmholtz (KH) instability occurring at cloud base its impact on modulating bottom altitudes are described by case study 8 October 2008 Shigaraki MU Observatory, Japan (34.85°N, 136.10°E). KH braids were monitored MUR along slope of gradually rising with time around an altitude ∼5.0 km. The had horizontal wavelength about 3.6 km maximum crest‐to‐trough amplitude...
The Biomass Burning and Lightning Experiment phase C (BIBLE‐C) aircraft mission was carried out near Darwin, Australia (12°S, 131°E) in December 2000. This the first experiment designed to estimate lightning NO production rates tropics, where is considered be most intense. During two flights (flights 10 13 made on 9 11–12, respectively) enhancements of x (NO + 2 ) up 1000 1600 parts per trillion by volume (pptv, 10‐s data) were observed at altitudes between 11.5 14 km. Geostationary...
Abstract. Water vapor observations by chilled-mirror hygrometers were conducted at Bandung, Indonesia (6.90° S, 107.60° E) and Tarawa, Kiribati (1.35° N, 172.91° in December 2003 to examine the efficiency of dehydration during horizontal advection tropical tropopause layer (TTL). Trajectory analyses based on bundles isentropic trajectories suggest that modification air parcels' identity due irreversible mixing branching-out merging-in nearby is found be an important factor, addition routes...
The Biomass Burning and Lightning Experiment phase A (BIBLE‐A) aircraft observation campaign was conducted from 24 September to 10 October 1998, during a La Niña period. During this campaign, distributions of ozone its precursors (NO, CO, nonmethane hydrocarbons (NMHCs)) were observed over the tropical Pacific Ocean, Indonesia, northern Australia. Mixing ratios very low at altitudes between 0 13.5 km Ocean. mixing above 8 Indonesia often significantly higher than those even though prevailing...
Ozone and water vapor observations have been conducted at Christmas/Kiritimati Island (2°N, 157°W) in the equatorial central Pacific as a part of Soundings Water Equatorial Region (SOWER)/Pacific mission. We launched 33 ozonesondes chilled‐mirror hygrometers nine observation campaigns from 1999 to 2003 for various seasons. found that ozone concentrations Christmas are low whole troposphere (∼10–35 ppbv), particularly marine boundary layer (MBL). variation is small throughout year compared...
Abstract. We apply the match technique, whereby same air mass is observed more than once and such cases are termed a "match", to study dehydration process associated with horizontal advection in tropical tropopause layer (TTL) over western Pacific. The matches obtained from profile data taken by Soundings of Ozone Water Equatorial Region (SOWER) campaign network observations using isentropic trajectories calculated European Centre for Medium-Range Weather Forecasts (ECMWF) operational...
Abstract This paper deals with the detection and quantification of refractivity turbulence in troposphere from radiosonde very high frequency (VHF) band radar data. Balloon data processing methods based on Thorpe sorting recently developed by Wilson et al. (2010, 2011, 2013) can be applied for a direct identification turbulent layers situ profiles. The VHF mid upper atmosphere (MUR) operated range‐imaging mode detecting monitoring at time range resolutions (of order 10 s few tens meters,...
Abstract. A network of balloon-borne radiosonde observations employing chilled-mirror hygrometers for water and electrochemical concentration cells ozone has been operated since the late 1990s in Tropical Pacific to capture evolution dehydration air parcels advected quasi-horizontally Tropopause Layer (TTL). The analysis this dataset is made on isentropes taking advantage conservative properties tracers moving adiabatically. existence ice particles diagnosed by lidars simultaneously with...
Using seven-year (1979-1985) rawinsonde data in the equatorial region, 30-60 day variation geopotential height (H) and temperature (T) fields their relations with fluctuations tonal wind (U) field are studied. After examining detail time series, lag-correlation method is applied to seven intervals of four month duration which show active variation. The main results as follows: (i) In H all troposphere T upper troposphere, zonal standing-wave-like structures a little phase differences found...
Abstract Vertical motion W profiles in the stratiform precipitation region of mesoscale cloud clusters were investigated using wind data observed by VHF Doppler radar installed western Sumatra Island (0.2°S, 100.32°E). A special mode for observations was introduced November 2003, and with high accuracy obtained during most period, fine resolutions 3 min time 150 m vertical direction. The typical structure within nimbostratus case study 6, 8, 20 2003. In later 2 or h gentle upward motions...
Using the European Centre for Medium‐Range Weather Forecasts 40 year reanalysis data zonal wind fields, we investigated characteristic variability and mean lifecycle of Kelvin waves around tropical tropopause layer upper troposphere. The distributions wave activity, squared amplitude, number passing cases closely resemble each other. disappearance locations relative to appearance longitudes were examined at 200 100 hPa. At hPa mostly appear in western hemisphere. highest‐frequency region is...
For the first time, trains of Kelvin‐Helmholtz billows ∼100–1500 m in depth persisting for about 60 hours at south extremity a tropopause fold are reported. The structures were monitored by VHF Middle and Upper atmosphere radar (Shigaraki, 34.85°N, 136.10°E) November 2008 base cirriform clouds simultaneously detected Ka‐band radar. ECWMF reanalysis data indicate that these advected spread out sub‐tropical jet‐stream from tropical storm area while dry cold air penetrated beneath upper‐level...
Vertical fine structure of tropical temperature profiles in the upper troposphere was analyzed with data obtained by global positioning system radio‐occultation limb‐sounding technique Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC), which has very high vertical resolution coverage. Inversion layers were detected using a 1 year record taken during 2007. They are observed most frequently boreal summer over Indian Ocean. The region characteristics shallow...
An aerosol layer was found 1–2 km around the tropical cold point tropopause by observations using ground‐based lidar and balloon‐borne optical particle counters (OPC) over Biak, Indonesia, in January 2011. The observed throughout survey period from 6 to 13 January. backscattering coefficient of about 5 times larger than that background aerosols. lidar‐observed depolarization ratio very low, wavelength dependence coefficients similar stratospheric A particles at size accumulation mode also an...
Abstract The stratospheric response to climate forcing, such as an increase in greenhouse gases, is often unpredictable because of interactions between radiation, dynamics, and chemistry. Climate models are unsuccessful simulating the realistic distribution water vapor. long-term trend age air (AoA), a measure that characterizes turnover time, remains inconsistent diagnoses estimates from tracer observations. For these reasons, observations designed specifically distinguish effects...
In situ aircraft measurements of O 3 , CO, total reactive nitrogen (NO y ), NO, and non‐methane hydrocarbons (NMHCs) were made over the western Pacific Ocean Australia during Biomass Burning Lightning Experiment (BIBLE) A B conducted in August–October 1998 1999. Generally, similar features seen BIBLE data latitudinal variations these species troposphere from 35°N to 28°S at longitudes 120°–150°E. The focus this paper is describe characteristics air masses sampled 15°N–10°S (tropical Pacific)...