GHG long-term trend viewer operation guide -RemoTeC-

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 RemoTeC CO2 and CH4 products are a joint development by SRON Netherlands Institute for Space Research and DLR. (Butz et al., GRL 2011; Guerlet et al., JGR 2013; Schepers et al, JGR 2012.)

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 V201.201

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

• xco2 :
  
  comment =Retrieved column-average dry-air mole fraction of atmospheric carbon dioxide (XCO2) in ppm
  long_name = column-average dry-air mole fraction of atmospheric carbon dioxide
  units = ppm
• xco2_quality_flag :
  
  comment = 0=good, 1=bad
  long_name = xco2_quality flag
• xch4:
  
  comment = Retrieved column-average dry-air mole fraction of atmospheric methane (XCH4) in ppb
  long_name = column-average dry-air mole fraction of atmospheric methane
  units = ppb
• xch4_quality_flag :
  
  comment = 0=good, 1=bad
  long_name = xch4_quality flag
• aerosol_central_height :
  
  comments = Peak height of the aerosol Gaussian height distribution
  long_name = Retrieved aerosol peak height
  units = m
• aerosol_size :
  
  comments = The size parameter is the exponent of the power-law slope of the aerosol size distribution
  long_name = Retrieved size parameter of the aerosol distribution
• aerosol_total_column :
  
  comments = The retrieved total aerosol column in units of particles m-2
  long_name = Retrieved aerosol total column
  units = m-2

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.

3. Citation

RemoTeC CITATION:

• ftp://ftp.sron.nl/pub/pub/RemoTeC/C3S/
  Users of RemoTec Data products should cite the following key RemoTeC references:
• Butz et al.,: Toward accurate CO2 and CH4 observations from GOSAT. Geophys. Res. Lett., 38, L14812, doi:10.1029/2011gl047888, 2011.
• Guerlet et al.,: Impact of aerosol and thin cirrus on retrieving and validating XCO2 from GOSAT shortwave infrared measurements, J. Geophys. Res. Atmos., 118, 4887-4905, doi:10.1002/jgrd.50332, 2013.
• Schepers et al.,: Methane retrievals from Greenhouse Gases Observing Satellite (GOSAT) shortwave infrared measurements: Performance comparison of proxy and physics retrieval algorithms. J. Geophys. Res., 117, D10307, doi:10.1029/2012jd017549, 2012.

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 SRON and DLR team, JAXA GOSAT project members.