NIES GOSAT retrieval

1. Introduction

The Greenhouse gases Observing SATellite "IBUKI" (GOSAT) is designed to measure the concentration of major greenhouse gases from space. GOSAT was launched successfully on January 23, 2009. GOSAT Project is a joint effort promoted by the Japan Aerospace Exploration Agency (JAXA), the National Institute for Environmental Studies (NIES) and the Ministry of the Environment (MOE).

The GHG long term trend viewer presents quick view and pick up data set of the target observation sites, where users are interested. Most of the target observations requested by the RA researchers are not included in the list.

2. Data description

L1B version

FTS L1B V230.231

L2 version

V03.05

About data category

• Airport (CONTRAIL)
  
  The CONTRAIL (Comprehensive Observation Network for TRace gases by AIrLiner) project is being jointly conducted by NIES (National Institute for Environmental Studies), the MRI (Meteorological Research Institute), JAL (Japan Airlines), JAMCO (JAMCO Corporation) and JAL-F (JAL Foundation). The CONTRAIL Database contains all the CO2 data measured by CME, as well as the information from the aircraft data system (aircraft position, temperature, wind direction and wind speed). These data have been used for GOSAT validation. GOSAT has targeted airports in serve.
• Possible Emission Source
  
  Possible large emission source site
• Megacity
  
  Highly populated cities urban area
• Calibration
  
  Vicarious calibration site
• TCCON (Total Carbon Column Observing Network)
  
  The Total Carbon Column Observing Network (TCCON) is a network of ground-based Fourier Transform Spectrometers that record spectra of the sun in the near-infrared. From these spectra, accurate and precise column-averaged abundances of atmospheric constituents including CO2, CH4, N2O, HF, CO, H2O, and HDO, are retrieved.
• Island and Others
  
  Targeting coasts and islands, while avoiding bays and channels in order to increase the yield rate of spectra.

About parameter

GOSAT NIES Level2 V03.05(Bias corrected)

• XCO2 :
  
  CO2 dry air mixing ratio is stored
  units = ppmv
• XCH4:
  
  CH4 dry air mixing ratio is stored
  units = ppmv
• AOT(0.76µm):
  
  Aerosol optical thickness at 0.76um is calculated from the retrieval state
  
• AOT(1.6µm):
  
  Aerosol optical thickness at 1.6um is calculated from the retrieval state
  
• AOT(2.06µm):
  
  Aerosol optical thickness at 2.06um is calculated from the retrieval state
  

About data extraction

In order to use long term trend data of the point of interest, the viewer pick up data within the circle of 10km radius.

But the following adjacent site, the viewer pick up within the circle of 1km or 2km radius.

The primary pointing system, which had been used between launch and Dec. 2014, larger pointing offset of about 5km.

Therefore, some cases include nearby target points.

The latitude and longitude of each site is summarized in Excel below
site list

3. Citation

NIES CITATION:

• GOSAT Data Archive Service (GDAS)
  https://data2.gosat.nies.go.jp/
  Users of NIES Data products should cite the following key NIES references:
• Morino et al., : Preliminary validation of column-averaged volume mixing ratios of carbon dioxide and methane retrieved from GOSAT short-wavelength infrared spectra, Atmos. Meas. Tech., 4, 1061-1076, doi:10.5194/amt-4-1061-2011, 2011.
• Yoshida et al., : Retrieval algorithm for CO2 and CH4 column abundances from short-wavelength infrared spectral observations by the Greenhouse gases observing satellite, Atmos. Meas. Tech., 4, 717-734, doi:10.5194/amt-4-717-2011, 2011.
• Yoshida et al., : Improvement of the retrieval algorithm for GOSAT SWIR XCO2 and XCH4 and their validation using TCCON data, Atmos. Meas. Tech., 6, 1533-1547, doi:10.5194/amt-6-1533-2013, 2013.

5. Links

• CONTRAIL
  http://www.cger.nies.go.jp/contrail/
• TCCON
  https://tccon-wiki.caltech.edu/

6. Acknowledgments

GHG Long term trend viewer was developed by JAXA/EORC. We would like to thank NIES GOSAT project members, and JAXA GOSAT project members.