A5045014716- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Atmospheric chemistry and aerosols
- Spectroscopy and Laser Applications
- Calibration and Measurement Techniques
- Atmospheric aerosols and clouds
- Air Quality Monitoring and Forecasting
- Hydrocarbon exploration and reservoir analysis
- Methane Hydrates and Related Phenomena
- Meteorological Phenomena and Simulations
- Geophysics and Gravity Measurements
- Remote Sensing in Agriculture
- Air Quality and Health Impacts
- Inertial Sensor and Navigation
- Fire Detection and Safety Systems
- Fire effects on ecosystems
- Nuclear Physics and Applications
- Climate change and permafrost
- Reservoir Engineering and Simulation Methods
- Urban Heat Island Mitigation
- Climate variability and models
- Geochemistry and Geologic Mapping
- Water Quality Monitoring and Analysis
- Remote-Sensing Image Classification
- COVID-19 impact on air quality
The University of Tokyo
2016-2025
Sphere Institute
2011-2022
South Ural State University
2010
National Institute for Environmental Studies
1999-2000
National Institute for Land and Infrastructure Management
1998
Nagoya University
1988
The ability to reliably estimate CO 2 fluxes from current in situ atmospheric measurements and future satellite is dependent on transport model performance at synoptic shorter timescales. TransCom continuous experiment was designed evaluate the of forward simulations hourly, daily, timescales, we focus latter two this paper. Twenty‐five models or variants submitted hourly time series nine predetermined tracers (seven for ) 280 locations. We extracted synoptic‐scale variability daily averaged...
Lidar measurements and airborne-particle collections were made during KOSARP 87 ('KOSA' Research Program of Nagoya University; April-May 1987) at (35°N, 137°E) to investigate the vertical distribution Asian dust (KOSA) particles transport these particles. According lidar measurements, highly concentrated particle layers with large depolarization ratio frequently in range from about 2 km 6 km.Electron microscope observations on morphology individual height near ground 4400 m suggested that...
A forward atmospheric transport modeling experiment has been coordinated by the TransCom group to investigate synoptic and diurnal variations in CO 2 . Model simulations were run for biospheric, fossil, air‐sea exchange of SF 6 radon 2000–2003. Twenty‐five models or model variants participated comparison. Hourly concentration time series submitted 280 sites along with vertical profiles, fluxes, meteorological variables at 100 sites. The results have analyzed are compared observed 2002. Mean...
Abstract The Greenhouse gases Observing SATellite 2 (GOSAT-2) was launched in October 2018 as a successor to GOSAT (launched 2009), the first satellite specialize greenhouse gas observations. Compared sensors, sensors of GOSAT-2 offer higher performance most respects. quality and quantity data from observations are expected be improved accordingly. signal-to-noise ratio (SNR) is better both SWIR TIR bands TANSO-FTS-2, which main sensor GOSAT-2. This improvement ultimately enhances accuracy...
Because very few measurements of atmospheric carbon dioxide (CO 2 ) are available in the tropics, estimates surface CO fluxes tropical regions beset with considerable uncertainties. To improve terrestrial fluxes, inversion was performed using passenger aircraft based Comprehensive Observation Network for Trace gases by Airliner (CONTRAIL) project addition to measurement data set GLOBALVIEW–CO . Regional monthly at earth's were estimated Bayesian synthesis approach focusing on period...
A tracer advection scheme for a three-dimensional icosahedral grid model is developed. Then, its transport performance evaluated using realistic flow fields. The consistency with continuity (CWC) newly introduced to three-dimensionally monotonic existing techniques of an upwind-biased and the intermediate density method. CWC guarantees mass conservation Lagrangian conservation, both which are important properties transport. In addition, positive definite. This implemented nonhydrostatic...
Abstract. Hyperspectral thermal infrared sounders enable us to grasp the global behavior of minor atmospheric constituents. Ammonia, which imparts large impacts on environment by reacting with other species, is one them. In this work, we present an ammonia retrieval system that developed for Greenhouse Gases Observing Satellite (GOSAT) and estimates column amounts derived from 2009 2014. The horizontal distributions seasonal represent significantly high values stemming six anthropogenic...
Abstract COVID-19 related restrictions lowered particulate matter and trace gas concentrations across cities around the world, providing a natural opportunity to study effects of anthropogenic activities on emissions air pollutants. In this paper, impact sudden suspension human pollution was analyzed by studying change in satellite retrieved NO 2 top-down NOx emission over urban rural areas Delhi. chosen for being most indicative intensity due its short lifetime order few hours planetary...
Exposure to particulate matter less than 2.5 µm in diameter (PM2.5) is a cause of concern cities and major emission regions northern India. An intensive field campaign involving the states Punjab, Haryana Delhi national capital region (NCR) was conducted 2022 using 29 Compact Useful PM2.5 Instrument with Gas sensors (CUPI-Gs). Continuous observations show that increased gradually from < 60 µg m-3 6-10 October up 500 on 5-9 November, which subsequently decreased about 100 20-30 November. Two...
The Greenhouse Gases Observing Satellite (GOSAT) was successfully launched in January 2009, with the aim of providing global observations greenhouse gases. We developed an algorithm to retrieve CO 2 vertical profiles from terrestrial radiation spectra at 700–800 cm −1 and assessed its validity. For this purpose, we first computed GOSAT pseudomeasurement then performed retrieval simulations using maximum a posteriori (MAP) method, analytical data for temperature information. Our no...
Abstract. A four-dimensional variational method (4D-Var) is a popular technique for source/sink inversions of atmospheric constituents, but it not without problems. Using an icosahedral grid transport model and the 4D-Var method, new greenhouse gas (GHG) inversion system has been developed. The combines offline forward adjoint models with quasi-Newton optimization scheme. approach then used to conduct identical twin experiments investigate optimal settings CO2 problem, demonstrate validity...
Abstract. Numerical simulation and validation of three-dimensional structure atmospheric carbon dioxide (CO2) is necessary for quantification transport model uncertainty its role on surface flux estimation by inverse modeling. Simulations CO2 were performed using four models two sets fluxes compared with an aircraft measurement dataset Comprehensive Observation Network Trace gases AIrLiner (CONTRAIL), covering various latitudes, longitudes, heights. Under this intercomparison project,...
Abstract. A four-dimensional variational (4D-Var) method is a popular algorithm for inverting atmospheric greenhouse gas (GHG) measurements. In order to meet the computationally intense 4D-Var iterative calculation, offline forward and adjoint transport models are developed based on Nonhydrostatic ICosahedral Atmospheric Model (NICAM). By introducing flexibility into temporal resolution of input meteorological data, model in this study not only efficient, it also found nearly match...
High-resolution Sentinel-2 imagery combined with a deep learning (DL) segmentation model offers promising approach for accurate mapping of small and fragmented agricultural burn areas. Initially, the was trained using ICNF area data from Portugal to capture large fire delineation, thereby achieving moderate accuracy. Subsequent fine-tuning annotated Punjab improved model’s ability detect patches, demonstrating higher accuracy than baseline Normalized Burn Ratio (NBR) Index method. On-ground...
High-resolution Sentinel-2 imagery combined with a deep learning (DL) segmentation model offers promising approach for accurate mapping of small and fragmented agricultural burn areas. Initially, the was trained using ICNF area data from Portugal to capture large fire delineation, thereby achieving moderate accuracy. Subsequent fine-tuning annotated Punjab improved model’s ability detect patches, demonstrating higher accuracy than baseline Normalized Burn Ratio (NBR) Index method. On-ground...
It is found that the possibly achieved higher accuracy cannot be obtained for all overlapping bands if only one scheme used to treat them in atmospheric absorption calculations. The commonly multiplication transmittance not acceptable when correlation existing practical spectra becomes strong. Therefore an optimized obtain k distribution parameters developed this paper based on completely uncorrelated, perfectly correlated, and partly correlated schemes. Two partial formulae are given paper....
Latitudinal distribution of the columnar deuterium/hydrogen ratio atmospheric water vapor, δ D vap , was retrieved from high‐resolution infrared spectra. Interferometric Monitor for Greenhouse gases (IMG) sensor aboard ADvanced Earth Observing Satellite (ADEOS) observed spectra over ocean during operational period December 1996 through June 1997. The latitudinal mean relatively large with values around −100‰ in tropical region decreasing down to minimal −800‰ at high latitudes. For...
The Thermal and Near-infrared Sensor for Carbon Observation Fourier Transform Spectrometer (TANSO-FTS) on board the Greenhouse Gases Observing Satellite (GOSAT) simultaneously observes column abundances profiles of CH4 in same field view, from shortwave infrared (SWIR) thermal (TIR) bands, respectively. We compared column-averaged dry-air mole fractions (XCH4) derived SWIR band, XCH4 calculated TIR profiles, data obtained over Guam airport by commercial aircraft. difference between SWIR-XCH4...
Abstract. The space and time variabilities of methane (CH4) total column upper tropospheric mixing ratios are analysed above the Mediterranean Basin (MB) as part Chemical Aerosol Experiment (ChArMEx) programme. Since analysis mid-to-upper CH4 distribution from spaceborne sensors model outputs is challenging, we have adopted a climatological approach used wide variety data sets. We combined measurements Thermal And Near infrared Sensor for carbon Observations – Fourier Transform Spectrometer...
Site environments and instrumental characteristics of carbon dioxide (CO2) measurements operated by local governments in the Kanto Plain, center which is Tokyo, were summarized for this study. The observation sites classified into three types: urban, suburban, woodland. Based on a few decades accumulated hourly data, diurnal seasonal variations CO2 concentrations analyzed as composite anomalies from annual means recorded each site. In urban areas, highest appear before midnight winter....
Abstract. The Thermal and Near Infrared Sensor for Carbon Observation (TANSO)–Fourier Transform Spectrometer (FTS) on board the Greenhouse Gases Observing Satellite (GOSAT) has been observing carbon dioxide (CO2) concentrations in several atmospheric layers thermal infrared (TIR) band since its launch. This study compared TANSO-FTS TIR version 1 (V1) CO2 data obtained Comprehensive Network TRace gases by AIrLiner (CONTRAIL) project upper troposphere lower stratosphere (UTLS), where of is...
Cities lying in the Indo-Gangetic plains of South Asia have world’s worst anthropogenic air pollution, which is often attributed to urban growth. Brick kilns, facilities for producing fired clay-bricks construction are found at peri-urban region Asian cities. Although brick kilns significant pollutant emitters, their contribution under-represented pollution emission inventories due unavailability distribution. This research overcomes this gap by proposing publicly available remote sensing...
Abstract. Light-absorbing black carbon (BC) aerosols strongly affect Earth's radiation budget and climate. This paper presents satellite retrieval of BC over India based on observations from the Cloud Aerosol Imager-2 (CAI-2) board Greenhouse gases Observing Satellite-2 (GOSAT-2). To evaluate validate retrievals, near-surface mass concentrations measured across Radiative Forcing NETwork (ARFINET) aerosol observatories are used. Then findings extended to elucidate global features. The...
Abstract. This paper investigates the scientific value of retrieving H218O and HDO columns in addition to H216O from high-resolution ground-based near-infrared spectra. We present a set refined H216O, H218O, spectral windows. The retrieved are used for an posteriori calculation columnar δD δ18O. estimate uncertainties so-calculated δ18O values. These estimations include due measurement noise, errors priori data, spectroscopic parameters. Time series obtained FTIR (Fourier transform infrared)...