Full-physics carbon dioxide retrievals from the Orbiting Carbon Observatory-2 (OCO-2) satellite by only using the 2.06 µm band
<p>Passive remote sensing of atmospheric carbon dioxide uses spectroscopic measurements of sunlight backscattered by the Earth's surface and atmosphere. The current state-of-the-art retrieval methods use three different spectral bands, the oxygen A band at <span class="inline-form...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-11-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://www.atmos-meas-tech.net/12/6049/2019/amt-12-6049-2019.pdf |
| Summary: | <p>Passive remote sensing of atmospheric carbon dioxide uses spectroscopic measurements of sunlight backscattered by the Earth's surface and atmosphere. The current state-of-the-art retrieval methods use three different spectral bands, the oxygen A band at <span class="inline-formula">0.76</span> <span class="inline-formula">µ</span>m and the weak and strong <span class="inline-formula">CO<sub>2</sub></span> absorption bands at <span class="inline-formula">1.61</span> and <span class="inline-formula">2.06</span> <span class="inline-formula">µ</span>m, respectively, to infer information on light scattering and the carbon dioxide column-averaged dry-air mole fraction <span class="inline-formula"><i>X</i>CO<sub>2</sub></span>. In this study, we propose a one-band <span class="inline-formula"><i>X</i>CO<sub>2</sub></span> retrieval technique which uses only the <span class="inline-formula">2.06</span> <span class="inline-formula">µ</span>m band measurements from the Orbiting Carbon Observatory-2 (OCO-2) satellite. We examine the data quality by comparing the OCO-2 <span class="inline-formula"><i>X</i>CO<sub>2</sub></span> with collocated ground-based measurements from the Total Carbon Column Observing Network (TCCON). Over land and ocean the OCO-2 one-band retrieval shows differences from TCCON observations with a standard deviation of <span class="inline-formula">∼1.30</span> ppm and a station-to-station variability of <span class="inline-formula">∼0.50</span> ppm. Moreover, we compare one-band and three-band retrievals over Europe, the Middle East, and Africa and see high correlation between the two retrievals with a SD of <span class="inline-formula">0.93</span> ppm. Compared to the three-band retrievals, <span class="inline-formula"><i>X</i>CO<sub>2</sub></span> retrievals using only the <span class="inline-formula">2.06</span> <span class="inline-formula">µ</span>m band have similar retrieval accuracy, precision, and data yield.</p> |
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| ISSN: | 1867-1381 1867-8548 |