On the zero-level offset in the GOSAT TANSO-FTS O<sub>2</sub> A band and the quality of solar-induced chlorophyll fluorescence (SIF): comparison of SIF between GOSAT and OCO-2
<p>Satellite remote sensing of solar-induced chlorophyll fluorescence (SIF) has attracted attention as a method for improving the estimation accuracy of the photosynthetic production of terrestrial vegetation in recent years. The Greenhouse gases Observing Satellite (GOSAT) has the ability to...
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doaj-07b71e6b00c54dc7aba93025dc578a052020-11-24T20:57:45ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482019-12-01126721673510.5194/amt-12-6721-2019On the zero-level offset in the GOSAT TANSO-FTS O<sub>2</sub> A band and the quality of solar-induced chlorophyll fluorescence (SIF): comparison of SIF between GOSAT and OCO-2H. OshioY. YoshidaT. Matsunaga<p>Satellite remote sensing of solar-induced chlorophyll fluorescence (SIF) has attracted attention as a method for improving the estimation accuracy of the photosynthetic production of terrestrial vegetation in recent years. The Greenhouse gases Observing Satellite (GOSAT) has the ability to observe both SIF and the concentrations of <span class="inline-formula">CO<sub>2</sub></span> and <span class="inline-formula">CH<sub>4</sub></span> and thus is expected to contribute to the understanding of the global carbon budget. Evaluating artefact signals (e.g. zero-level offset caused by non-linearity in the analogue circuit in the case of GOSAT) is effective for inferring the instrument status and important for retrieving SIF from satellite measurements. Here we investigate the characteristics of the zero-level offset and the consistency of satellite-derived SIFs by comparing the derived SIF with the Orbiting Carbon Observatory-2 (OCO-2) SIF at multiple spatial scales (footprint to global). The zero-level offset was evaluated using filling-in signals over bare soil while investigating the criteria for identifying barren areas. An analysis of the temporal variation of the zero-level offset over a period of 9 years suggests that the radiometric sensitivity of the GOSAT spectrometer changed after switching the optics path selector in January 2015. The GOSAT SIF was highly consistent with the OCO-2 SIF, with a bias within 0.1 mW m<span class="inline-formula"><sup>−2</sup></span> nm<span class="inline-formula"><sup>−1</sup></span> sr<span class="inline-formula"><sup>−1</sup></span> for most months and an inter-region bias of about 0.2 mW m<span class="inline-formula"><sup>−2</sup></span> nm<span class="inline-formula"><sup>−1</sup></span> sr<span class="inline-formula"><sup>−1</sup></span>. Our results agree with the previous comparisons and support the consistency among the present satellite SIF data, which is important for the utilization of those data.</p>https://www.atmos-meas-tech.net/12/6721/2019/amt-12-6721-2019.pdf |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
H. Oshio Y. Yoshida T. Matsunaga |
spellingShingle |
H. Oshio Y. Yoshida T. Matsunaga On the zero-level offset in the GOSAT TANSO-FTS O<sub>2</sub> A band and the quality of solar-induced chlorophyll fluorescence (SIF): comparison of SIF between GOSAT and OCO-2 Atmospheric Measurement Techniques |
author_facet |
H. Oshio Y. Yoshida T. Matsunaga |
author_sort |
H. Oshio |
title |
On the zero-level offset in the GOSAT TANSO-FTS O<sub>2</sub> A band and the quality of solar-induced chlorophyll fluorescence (SIF): comparison of SIF between GOSAT and OCO-2 |
title_short |
On the zero-level offset in the GOSAT TANSO-FTS O<sub>2</sub> A band and the quality of solar-induced chlorophyll fluorescence (SIF): comparison of SIF between GOSAT and OCO-2 |
title_full |
On the zero-level offset in the GOSAT TANSO-FTS O<sub>2</sub> A band and the quality of solar-induced chlorophyll fluorescence (SIF): comparison of SIF between GOSAT and OCO-2 |
title_fullStr |
On the zero-level offset in the GOSAT TANSO-FTS O<sub>2</sub> A band and the quality of solar-induced chlorophyll fluorescence (SIF): comparison of SIF between GOSAT and OCO-2 |
title_full_unstemmed |
On the zero-level offset in the GOSAT TANSO-FTS O<sub>2</sub> A band and the quality of solar-induced chlorophyll fluorescence (SIF): comparison of SIF between GOSAT and OCO-2 |
title_sort |
on the zero-level offset in the gosat tanso-fts o<sub>2</sub> a band and the quality of solar-induced chlorophyll fluorescence (sif): comparison of sif between gosat and oco-2 |
publisher |
Copernicus Publications |
series |
Atmospheric Measurement Techniques |
issn |
1867-1381 1867-8548 |
publishDate |
2019-12-01 |
description |
<p>Satellite remote sensing of solar-induced chlorophyll
fluorescence (SIF) has attracted attention as a method for improving the
estimation accuracy of the photosynthetic production of terrestrial
vegetation in recent years. The Greenhouse gases Observing Satellite (GOSAT)
has the ability to observe both SIF and the concentrations of <span class="inline-formula">CO<sub>2</sub></span> and
<span class="inline-formula">CH<sub>4</sub></span> and thus is expected to contribute to the understanding of the global
carbon budget. Evaluating artefact signals (e.g. zero-level offset caused
by non-linearity in the analogue circuit in the case of GOSAT) is effective
for inferring the instrument status and important for retrieving SIF from
satellite measurements. Here we investigate the characteristics of the
zero-level offset and the consistency of satellite-derived SIFs by comparing
the derived SIF with the Orbiting Carbon Observatory-2 (OCO-2) SIF at
multiple spatial scales (footprint to global). The zero-level offset was
evaluated using filling-in signals over bare soil while investigating the
criteria for identifying barren areas. An analysis of the temporal variation
of the zero-level offset over a period of 9 years suggests that the
radiometric sensitivity of the GOSAT spectrometer changed after switching
the optics path selector in January 2015. The GOSAT SIF was highly
consistent with the OCO-2 SIF, with a bias within 0.1 mW m<span class="inline-formula"><sup>−2</sup></span> nm<span class="inline-formula"><sup>−1</sup></span> sr<span class="inline-formula"><sup>−1</sup></span> for most months and an inter-region bias of about 0.2 mW m<span class="inline-formula"><sup>−2</sup></span> nm<span class="inline-formula"><sup>−1</sup></span> sr<span class="inline-formula"><sup>−1</sup></span>. Our results agree with the previous comparisons and
support the consistency among the present satellite SIF data, which is
important for the utilization of those data.</p> |
url |
https://www.atmos-meas-tech.net/12/6721/2019/amt-12-6721-2019.pdf |
work_keys_str_mv |
AT hoshio onthezeroleveloffsetinthegosattansoftsosub2subabandandthequalityofsolarinducedchlorophyllfluorescencesifcomparisonofsifbetweengosatandoco2 AT yyoshida onthezeroleveloffsetinthegosattansoftsosub2subabandandthequalityofsolarinducedchlorophyllfluorescencesifcomparisonofsifbetweengosatandoco2 AT tmatsunaga onthezeroleveloffsetinthegosattansoftsosub2subabandandthequalityofsolarinducedchlorophyllfluorescencesifcomparisonofsifbetweengosatandoco2 |
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