Validation of the Aeolus L2B wind product with airborne wind lidar measurements in the polar North Atlantic region and in the tropics
<p>During the first 3 years of the European Space Agency's Aeolus mission, the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt, DLR) performed four airborne campaigns deploying two different Doppler wind lidars (DWL) on board the DLR Falcon aircraft, aiming to validate...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2022-12-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://amt.copernicus.org/articles/15/7049/2022/amt-15-7049-2022.pdf |
| _version_ | 1828091333515935744 |
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| author | B. Witschas C. Lemmerz A. Geiß O. Lux U. Marksteiner S. Rahm O. Reitebuch A. Schäfler F. Weiler |
| author_facet | B. Witschas C. Lemmerz A. Geiß O. Lux U. Marksteiner S. Rahm O. Reitebuch A. Schäfler F. Weiler |
| author_sort | B. Witschas |
| collection | DOAJ |
| description | <p>During the first 3 years of the European Space Agency's Aeolus mission, the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt, DLR) performed four airborne campaigns deploying two different Doppler wind lidars (DWL) on board the DLR Falcon aircraft, aiming to validate the quality of the recent Aeolus Level 2B (L2B) wind data product (processor baseline 11 and 12). The first two campaigns, WindVal III (November–December 2018) and AVATAR-E (Aeolus Validation Through Airborne Lidars in Europe, May and June 2019), were conducted in Europe and provided first insights into the data quality at the beginning of the mission phase. The two later campaigns, AVATAR-I (Aeolus Validation Through Airborne Lidars in Iceland) and AVATAR-T (Aeolus Validation Through Airborne Lidars in the Tropics), were performed in regions of particular interest for the Aeolus validation: AVATAR-I was conducted from Keflavik, Iceland, between 9 September and 1 October 2019 to sample the high wind speeds in the vicinity of the polar jet stream; AVATAR-T was carried out from Sal, Cape Verde, between 6 and 28 September 2021 to measure winds in the Saharan dust-laden African easterly jet. Altogether, 10 Aeolus underflights were performed during AVATAR-I and 11 underflights during AVATAR-T, covering about 8000 and 11 000 km along the Aeolus measurement track, respectively.
Based on these collocated measurements, statistical comparisons of Aeolus data with the reference lidar (2 <span class="inline-formula">µ</span>m DWL) as well as with in situ measurements by the Falcon were performed to determine the systematic and random errors of Rayleigh-clear and Mie-cloudy winds that are contained in the Aeolus L2B product. It is demonstrated that the systematic error almost fulfills the mission requirement of being below <span class="inline-formula">0.7</span> m s<span class="inline-formula"><sup>−1</sup></span> for both Rayleigh-clear and Mie-cloudy winds. The random error is shown to vary between <span class="inline-formula">5.5</span> and <span class="inline-formula">7.1</span> m s<span class="inline-formula"><sup>−1</sup></span> for Rayleigh-clear winds and is thus larger than specified (<span class="inline-formula">2.5</span> m s<span class="inline-formula"><sup>−1</sup></span>), whereas it is close to the specifications for Mie-cloudy winds (<span class="inline-formula">2.7 to 2.9</span> m s<span class="inline-formula"><sup>−1</sup></span>). In addition, the dependency of the systematic and random errors on the actual wind speed, the geolocation, the scattering ratio, and the time difference between 2 <span class="inline-formula">µ</span>m DWL observation and satellite overflight is investigated and discussed. Thus, this work contributes to the characterization of the Aeolus data quality in different meteorological situations and allows one to investigate wind retrieval algorithm improvements for reprocessed Aeolus data sets.</p> |
| first_indexed | 2024-04-11T06:11:19Z |
| format | Article |
| id | doaj.art-de54ce6bccc2494f9b7e64576b2f63de |
| institution | Directory Open Access Journal |
| issn | 1867-1381 1867-8548 |
| language | English |
| last_indexed | 2024-04-11T06:11:19Z |
| publishDate | 2022-12-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Measurement Techniques |
| spelling | doaj.art-de54ce6bccc2494f9b7e64576b2f63de2022-12-22T04:41:15ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482022-12-01157049707010.5194/amt-15-7049-2022Validation of the Aeolus L2B wind product with airborne wind lidar measurements in the polar North Atlantic region and in the tropicsB. Witschas0C. Lemmerz1A. Geiß2O. Lux3U. Marksteiner4S. Rahm5O. Reitebuch6A. Schäfler7F. Weiler8Institut für Physik der Atmosphäre, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), 82234 Oberpfaffenhofen, GermanyInstitut für Physik der Atmosphäre, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), 82234 Oberpfaffenhofen, GermanyMeteorologisches Institut, Ludwig-Maximilians-Universität, 80333 Munich, GermanyInstitut für Physik der Atmosphäre, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), 82234 Oberpfaffenhofen, GermanyInstitut für Physik der Atmosphäre, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), 82234 Oberpfaffenhofen, GermanyInstitut für Physik der Atmosphäre, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), 82234 Oberpfaffenhofen, GermanyInstitut für Physik der Atmosphäre, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), 82234 Oberpfaffenhofen, GermanyInstitut für Physik der Atmosphäre, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), 82234 Oberpfaffenhofen, GermanyInstitut für Physik der Atmosphäre, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), 82234 Oberpfaffenhofen, Germany<p>During the first 3 years of the European Space Agency's Aeolus mission, the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt, DLR) performed four airborne campaigns deploying two different Doppler wind lidars (DWL) on board the DLR Falcon aircraft, aiming to validate the quality of the recent Aeolus Level 2B (L2B) wind data product (processor baseline 11 and 12). The first two campaigns, WindVal III (November–December 2018) and AVATAR-E (Aeolus Validation Through Airborne Lidars in Europe, May and June 2019), were conducted in Europe and provided first insights into the data quality at the beginning of the mission phase. The two later campaigns, AVATAR-I (Aeolus Validation Through Airborne Lidars in Iceland) and AVATAR-T (Aeolus Validation Through Airborne Lidars in the Tropics), were performed in regions of particular interest for the Aeolus validation: AVATAR-I was conducted from Keflavik, Iceland, between 9 September and 1 October 2019 to sample the high wind speeds in the vicinity of the polar jet stream; AVATAR-T was carried out from Sal, Cape Verde, between 6 and 28 September 2021 to measure winds in the Saharan dust-laden African easterly jet. Altogether, 10 Aeolus underflights were performed during AVATAR-I and 11 underflights during AVATAR-T, covering about 8000 and 11 000 km along the Aeolus measurement track, respectively. Based on these collocated measurements, statistical comparisons of Aeolus data with the reference lidar (2 <span class="inline-formula">µ</span>m DWL) as well as with in situ measurements by the Falcon were performed to determine the systematic and random errors of Rayleigh-clear and Mie-cloudy winds that are contained in the Aeolus L2B product. It is demonstrated that the systematic error almost fulfills the mission requirement of being below <span class="inline-formula">0.7</span> m s<span class="inline-formula"><sup>−1</sup></span> for both Rayleigh-clear and Mie-cloudy winds. The random error is shown to vary between <span class="inline-formula">5.5</span> and <span class="inline-formula">7.1</span> m s<span class="inline-formula"><sup>−1</sup></span> for Rayleigh-clear winds and is thus larger than specified (<span class="inline-formula">2.5</span> m s<span class="inline-formula"><sup>−1</sup></span>), whereas it is close to the specifications for Mie-cloudy winds (<span class="inline-formula">2.7 to 2.9</span> m s<span class="inline-formula"><sup>−1</sup></span>). In addition, the dependency of the systematic and random errors on the actual wind speed, the geolocation, the scattering ratio, and the time difference between 2 <span class="inline-formula">µ</span>m DWL observation and satellite overflight is investigated and discussed. Thus, this work contributes to the characterization of the Aeolus data quality in different meteorological situations and allows one to investigate wind retrieval algorithm improvements for reprocessed Aeolus data sets.</p>https://amt.copernicus.org/articles/15/7049/2022/amt-15-7049-2022.pdf |
| spellingShingle | B. Witschas C. Lemmerz A. Geiß O. Lux U. Marksteiner S. Rahm O. Reitebuch A. Schäfler F. Weiler Validation of the Aeolus L2B wind product with airborne wind lidar measurements in the polar North Atlantic region and in the tropics Atmospheric Measurement Techniques |
| title | Validation of the Aeolus L2B wind product with airborne wind lidar measurements in the polar North Atlantic region and in the tropics |
| title_full | Validation of the Aeolus L2B wind product with airborne wind lidar measurements in the polar North Atlantic region and in the tropics |
| title_fullStr | Validation of the Aeolus L2B wind product with airborne wind lidar measurements in the polar North Atlantic region and in the tropics |
| title_full_unstemmed | Validation of the Aeolus L2B wind product with airborne wind lidar measurements in the polar North Atlantic region and in the tropics |
| title_short | Validation of the Aeolus L2B wind product with airborne wind lidar measurements in the polar North Atlantic region and in the tropics |
| title_sort | validation of the aeolus l2b wind product with airborne wind lidar measurements in the polar north atlantic region and in the tropics |
| url | https://amt.copernicus.org/articles/15/7049/2022/amt-15-7049-2022.pdf |
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