How bias correction goes wrong: measurement of XCO2 affected by erroneous surface pressure estimates
By Matthäus Kiel, Christopher W. O'Dell, Brendan M. Fisher, Annmarie Eldering, R. Nassar, Cameron G. MacDonald, Paul O. Wennberg. Atmospheric Measurement Techniques, 2019
167 citations recorded by the source corpus.
Abstract. All measurements of XCO2 from space have systematic errors. To reduce a large fraction of these errors, a bias correction is applied to XCO2 retrieved from GOSAT and OCO-2 spectra using the ACOS retrieval algorithm. The bias correction uses, among other parameters, the surface pressure difference between the retrieval and the meteorological reanalysis. Relative errors in the surface pressure estimates, however, propagate nearly 1:1 into relative errors in bias-corrected XCO2. For OCO-2, small errors in the knowledge of the pointing of the observatory (up to ∼130 arcsec) introduce a bias in XCO2 in regions with rough topography. Erroneous surface pressure estimates are also caused by a coding error in ACOS version 8, sampling meteorological analyses at wrong times (up to 3 h after the overpass time). Here, we derive new geolocations for OCO-2's eight footprints and show how using improved knowledge of surface pressure estimates in the bias correction reduces errors in OCO-2's v9 XCO2 data.
Subfields: Artificial Intelligence, Global and Planetary Change, Mechanics of Materials
View Paper: https://www.semanticscholar.org/paper/808fffc84ee2d14c3b57ef440c6e5695eb9b5a99
How researchers see this paper
The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.
In Artificial Intelligence
In Global and Planetary Change
- Paul O. Wennberg
- David Crisp
- Christopher W. O'Dell
- Brendan M. Fisher
- Annmarie Eldering
- Matthäus Kiel
- T. Kurosu
- Christian Frankenberg
Citations in the corpus
- OCO-3 early mission operations and initial (vEarly) XCO2 and SIF retrievals (2020, methodology): “The variables and values in this table can be compared to those for OCO-2 v8 reported in table A1 of (O'Dell et al., 2018) and those for OCO-2 v9 reported in table 5 of (Kiel et al., 2019).”