Identifying and Correcting for Residual Biases in the ASCAT and ERA5 Wind Speed Products

The advanced scatterometer (ASCAT) instrument is a real-aperture radar that operates at C-band and measures backscatter from the ocean surface, from which near surface wind speed is estimated. However, the variance of radar backscatter is not completely explained by that of the near surface wind speed, and there are other environmental factors that can also perturb the backscatter. The ASCAT wind speed retrieval algorithm attempts to correct for the other factors, and it is largely successful. We examine here two environmental factors, precipitation and atmospheric stability at the surface, which are found to correlate strongly with residual biases in the ASCAT and ERA5 wind speed products. Correction algorithms are developed to remove the dependence of bias on these two environmental variables on both wind speed products. With the corrections applied, ASCAT’s mean global wind speed bias is reduced and regional variations in the bias are narrowed. As one example of the impact of the biases, they are estimated to cause a 2.1% average global error in latent heat flux transferred from the ocean to the atmosphere.

• Publication year

  2026

• Venue

  IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing

• Publication date

  Unknown publication date

• Fields of study

  Physics, Computer Science, Environmental Science

• Identifiers
  DOI 10.1109/JSTARS.2025.3631136
• External record

  Open on Semantic Scholar

• Source metadata

  Semantic Scholar

• No claims are published for this paper.

• No concepts are published for this paper.

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