تقرير
أعرض في EDS

Improved SIFTER v2 algorithm for long-term GOME-2A satellite retrievals of fluorescence with a correction for instrument degradation

التفاصيل البيبلوغرافية
العنوان: Improved SIFTER v2 algorithm for long-term GOME-2A satellite retrievals of fluorescence with a correction for instrument degradation
المؤلفون: Erik van Schaik, Maurits L. Kooreman, Piet Stammes, L. Gijsbert Tilstra, Olaf N. E. Tuinder, Abram F. J. Sanders, Willem W. Verstraeten, Rüdiger Lang, Alessandra Cacciari, Joanna Joiner, Wouter Peters, Klass Folkert Boersma
المصدر: Atmospheric Measurement Techniques. 13(8)
بيانات النشر: United States: NASA Center for Aerospace Information (CASI), 2020.
سنة النشر: 2020
مصطلحات موضوعية: Geosciences (General)
الوصف: Solar-induced fluorescence (SIF) data from satellites are increasingly used as a proxy for photosynthetic activity by vegetation, and as a constraint on gross primary production. Here we report on improvements in the algorithm to retrieve mid-morning (09:30 hrs local time) SIF estimates on the global scale from GOME-2 sensor on the Metop-A satellite (GOME-2A) for the period 2007-2019. Our new SIFTER (Sun-Induced Fluorescence of Terrestrial Ecosystems Retrieval) v2 algorithm improves over a previous version by using a narrower spectral window that avoids strong oxygen absorption and is less sensitive to water vapour absorption, by constructing stable reference spectra from a 6-year period (2007-2012) of atmospheric spectra over the Sahara, and by applying a latitude-dependent zero-level adjustment that accounts for biases in the data product. We generated stable, good-quality SIF retrievals between January 2007 and June 2013, when GOME-2A degradation in the near infrared was still limited. After the narrowing of the GOME-2A swath in July 2013, we characterized the throughput degradation of the level-1 data in order to derive reflectance corrections and apply these for the SIF retrievals between July 2013 and December 2018. SIFTER v2 data compares well with the independent NASA v2.8 data product. Especially in the evergreen tropics, SIFTER v2 no longer shows the underestimates against other satellite products that were seen in SIFTER v1. The new data product includes uncertainty estimates for individual observations, and is best used for mostly clear-sky scenes, and when spectral residuals remain below a certain spectral autocorrelation threshold. Our results support the use of SIFTER v2 data to be used as an independent constraint on photosynthetic activity on regional to global scales.
نوع الوثيقة: Report
اللغة: English
تدمد: 1867-8548
1867-1381
DOI: 10.5194/amt-13-4295-2020
DOI: 10.5194/amt-13-4295-2020-supplement
URL الوصول: https://ntrs.nasa.gov/citations/20210014806
ملاحظات: 281945.02.61.04.96

ASICA 649087
رقم الأكسشن: edsnas.20210014806
قاعدة البيانات: NASA Technical Reports
الوصف
تدمد:18678548
18671381
DOI:10.5194/amt-13-4295-2020