Hirofumi Ohyama
A5079421124- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Atmospheric chemistry and aerosols
- Spectroscopy and Laser Applications
- Geophysics and Gravity Measurements
- Hydrocarbon exploration and reservoir analysis
- Geochemistry and Geologic Mapping
- Ionosphere and magnetosphere dynamics
- Methane Hydrates and Related Phenomena
- Calibration and Measurement Techniques
- Air Quality Monitoring and Forecasting
- Geological and Geophysical Studies
- Carbon Dioxide Capture Technologies
- Inertial Sensor and Navigation
- Meteorological Phenomena and Simulations
- Climate variability and models
- Atmospheric aerosols and clouds
- Reservoir Engineering and Simulation Methods
- Wind and Air Flow Studies
- Cryospheric studies and observations
- Fire effects on ecosystems
- Earthquake Detection and Analysis
- Environmental Impact and Sustainability
- GNSS positioning and interference
- Solar and Space Plasma Dynamics
National Institute for Environmental Studies
2009-2025
Japan Aerospace Exploration Agency
2009-2018
Nagoya University
2014-2018
Saga University
2018
Earth and Space Research
2016-2017
Institute of Solar-Terrestrial Physics
2014-2015
Nagoya City University
2014
Kobe University
2009
Abstract. Since September 2014, NASA's Orbiting Carbon Observatory-2 (OCO-2) satellite has been taking measurements of reflected solar spectra and using them to infer atmospheric carbon dioxide levels. This work provides details the OCO-2 retrieval algorithm, versions 7 8, used derive column-averaged dry air mole fraction CO2 (XCO2) for roughly 100 000 cloud-free recorded by each day. The algorithm is based on Atmospheric Observations from Space (ACOS) which applied observations Greenhouse...
Abstract. We use 2009–2011 space-borne methane observations from the Greenhouse Gases Observing SATellite (GOSAT) to estimate global and North American emissions with 4° × 5° up 50 km spatial resolution, respectively. GEOS-Chem GOSAT data are first evaluated atmospheric surface tower networks (NOAA/ESRL, TCCON) aircraft HIPPO), using chemical transport model as a platform facilitate comparison of in situ data. This identifies high-latitude bias between that we correct via quadratic...
Abstract. In a 3.5-year long study, the long-term performance of mobile, solar absorption Bruker EM27/SUN spectrometer, used for greenhouse gas observations, is checked with respect to co-located reference IFS 125HR which part Total Carbon Column Observing Network (TCCON). We find that stable on timescales several years; drift per year between and official TCCON product 0.02 ppmv XCO2 0.9 ppbv XCH4, within 1σ precision comparison, 0.6 4.3 XCH4. The bias two data sets 3.9 13.0 order avoid...
Abstract. The Sentinel-5 Precursor (S5P) mission with the TROPOspheric Monitoring Instrument (TROPOMI) on board has been measuring solar radiation backscattered by Earth's atmosphere and surface since its launch 13 October 2017. In this paper, we present for first time S5P operational methane (CH4) carbon monoxide (CO) products' validation results covering a period of about 3 years using global Total Carbon Column Observing Network (TCCON) Infrared Working Group Detection Atmospheric...
Abstract. Accurate accounting of emissions and removals CO2 is critical for the planning verification emission reduction targets in support Paris Agreement. Here, we present a pilot dataset country-specific net carbon exchange (NCE; fossil plus terrestrial ecosystem fluxes) stock changes aimed at informing countries' budgets. These estimates are based on “top-down” NCE outputs from v10 Orbiting Carbon Observatory (OCO-2) modeling intercomparison project (MIP), wherein an ensemble inverse...
Abstract. The Total Carbon Column Observing Network (TCCON) measures column-average mole fractions of several greenhouse gases (GHGs) beginning in 2004 from over 30 current or past measurement sites around the world, using solar absorption spectroscopy near infrared region. TCCON GHG data have been used extensively for multiple purposes, including studies carbon cycle and anthropogenic emissions as well to validate improve observations made spacebased sensors. Here, we describe an update...
Abstract. The Total Carbon Column Observing Network (TCCON) measures column-average mole fractions of several greenhouse gases (GHGs), beginning in 2004, from over 30 current or past measurement sites around the world using solar absorption spectroscopy near-infrared (near-IR) region. TCCON GHG data have been used extensively for multiple purposes, including studies carbon cycle and anthropogenic emissions, as well to validate improve observations space-based sensors. Here, we describe an...
Abstract. This work presents the latest release (v9.0) of University Leicester GOSAT Proxy XCH4 dataset. Since launch satellite in 2009, these data have been produced by UK National Centre for Earth Observation (NCEO) as part ESA Greenhouse Gas Climate Change Initiative (GHG-CCI) and Copernicus Services (C3S) projects. With now over a decade observations, we outline many scientific studies achieved using past versions order to highlight how this version may be used future. We describe detail...
Abstract. In this study, an extension on the previously reported status of COllaborative Carbon Column Observing Network's (COCCON) calibration procedures incorporating refined methods is presented. COCCON a global network portable Bruker EM27/SUN FTIR spectrometers for deriving column-averaged atmospheric abundances greenhouse gases. The original laboratory open-path lamp measurements instrumental line shape (ILS) spectrometer from water vapour lines have been and extended to secondary...
Abstract. The Thermal And Near infrared Sensor for carbon Observation – Fourier Transform Spectrometer (TANSO-FTS) on the Japanese Greenhouse gases Observing SATellite (GOSAT) has been returning data since April 2009. version 9 (v9) Atmospheric Carbon Observations from Space (ACOS) Level 2 Full Physics (L2FP) retrieval algorithm (Kiel et al., 2019) was used to derive estimates of dioxide (CO2) dry air mole fraction (XCO2) TANSO-FTS measurements collected over its first 11 years operation....
The COllaborative Carbon Column Observing Network has become a reliable source of high-quality ground-based remote sensing network data that provide column-averaged dry-air mole fractions carbon dioxide (XCO2), methane (XCH4), and monoxide (XCO). fiducial reference measurements these gases from the COCCON complement TCCON NDACC-IRWG data. This study shows application for validation existing greenhouse gas satellite products. includes XCH4 XCO products European Copernicus Sentinel-5 Precursor...
Abstract. In this study we present the retrieval of column-averaged dry air mole fraction carbon dioxide (XCO2) from Orbiting Carbon Observatory-2 (OCO-2) satellite observations using RemoTeC algorithm, previously successfully applied to greenhouse gas concentration Greenhouse Gases Observing Satellite (GOSAT). The XCO2 product has been validated with collocated ground-based measurements Total Column Network (TCCON) for almost 2 years OCO-2 data September 2014 July 2016. We found that...
Abstract TanSat is the 1st Chinese carbon dioxide (CO 2 ) measurement satellite, launched in 2016. In this study, University of Leicester Full Physics (UoL‐FP) algorithm implemented for nadir mode XCO retrievals. We develop a spectrum correction method to reduce retrieval errors by online fitting an 8 th order Fourier series. The spectrum‐correction model and its priori parameters are developed analyzing solar calibration measurement. This provides significant improvement O A band retrieval....
Abstract. Since 2009, the Greenhouse gases Observing SATellite (GOSAT) has performed radiance measurements in near-infrared (NIR) and shortwave infrared (SWIR) spectral region. From February 2019 onward, data from GOSAT-2 have also been available. We present first results application of Fast atmOspheric traCe gAs retrievaL (FOCAL) algorithm to derive column-averaged dry-air mole fractions carbon dioxide (XCO2) GOSAT radiances their validation. FOCAL was initially developed for OCO-2 XCO2...
Abstract. We show new results from an updated version of the Fast atmOspheric traCe gAs retrievaL (FOCAL) retrieval method applied to measurements Greenhouse gases Observing SATellite (GOSAT) and its successor GOSAT-2. FOCAL was originally developed for estimating total column carbon dioxide mixing ratio (XCO2) spectral made by Orbiting Carbon Observatory-2 (OCO-2). However, depending on available windows, also successfully retrieves amounts other atmospheric species their uncertainties...
This work describes the radiometric calibration of short-wave infrared (SWIR) bands two instruments aboard Greenhouse gases Observing SATellite (GOSAT), Thermal And Near Sensor for carbon Observations Fourier Transform Spectrometer (TANSO-FTS) and Cloud Aerosol Imager (TANSO-CAI). Four vicarious campaigns (VCCs) have been performed annually since June 2009 at Railroad Valley, NV, USA, to estimate changes in response both sensors. While campaign ( VCC <sup...
Abstract. Observations of carbon monoxide (CO) from the Measurements Of Pollution In The Troposphere (MOPITT) instrument aboard Terra spacecraft were expected to have an accuracy 10 % prior launch in 1999. Here we evaluate MOPITT Version 7 joint (V7J) thermal-infrared and near-infrared (TIR–NIR) retrieval precision suggest ways further improve observations. We take five steps involving filtering or bias corrections reduce scatter data relative other soundings ground-based measurements. (1)...
This study presents an approach for generating a global land mapping dataset of the satellite measurements CO2 total column (XCO2) using spatio-temporal geostatistics, which makes full use joint spatial and temporal dependencies between observations. The considers latitude-zonal seasonal cycles correlation structure XCO2, obtains maps with grid resolution 1° latitude by longitude 3 days. We evaluate accuracy uncertainty in following three ways: (1) cross-validation, results high coefficient...
Abstract. Urban areas are responsible for more than 40 % of global energy-related carbon dioxide (CO2) emissions. The Tokyo metropolitan area (TMA), Japan, one the most populated regions in world, includes various emission sources, such as thermal power plants, automobile traffic, and residential facilities. In order to infer a top–down estimate, we conducted an intensive field campaign TMA from February April 2016 measure column-averaged dry-air mole fractions CO2 (XCO2) with three...
Abstract. Since September 2014, NASA's Orbiting Carbon Observatory-2 (OCO-2) satellite has been taking measurements of reflected solar spectra and using them to infer atmospheric carbon dioxide levels. This work provides details the OCO-2 retrieval algorithm, versions 7 8, used derive column-averaged dry air mole fraction CO2,/sub> (XCO2) for roughly 100,000 cloud-free recorded by each day. The algorithm is based on Atmospheric Observations from Space (ACOS) which applied observations...
This paper provides an overview of the validation National Oceanic and Atmospheric Administration (NOAA) operational retrievals atmospheric carbon trace gas profiles, specifically monoxide (CO), methane (CH4) dioxide (CO2), from NOAA-Unique Combined Processing System (NUCAPS), a NOAA enterprise algorithm that retrieves profile environmental data records (EDRs) under global non-precipitating (clear to partly cloudy) conditions. Vertical information about gases is obtained Cross-track Infrared...
Abstract The Japanese Global Observing SATellite for Greenhouse gases and Water cycle (GOSAT-GW) will be an Earth-observing satellite to conduct global observations of atmospheric carbon dioxide (CO 2 ), methane (CH 4 nitrogen (NO ) simultaneously from a single platform. GOSAT-GW is the third in series currently operating (GOSAT) GOSAT-2. It carry two sensors, Total Anthropogenic Natural emissions mapping SpectrOmeter-3 (TANSO-3) Advanced Microwave Scanning Radiometer 3 (AMSR3), with latter...
Abstract. Satellite-driven inversions provide valuable information about methane (CH4) fluxes, but the assimilation of total column-averaged dry-air mole fractions CH4 (XCH4) has been challenging. This study explores, for first time, potential new lower tropospheric partial column (pXCH4_LT) GOSAT data, retrieved by Japan Aerospace Exploration Agency (JAXA), to constrain global and regional fluxes. Using CarbonTracker Europe-CH4 atmospheric inverse model, we estimated fluxes between...