Are you using a physical SST method or generating SST CDRs? The latest publication from GHRSST Science Team Members, Yukio Kurihara and Misako Kachi, Cross-Calibration of the Himawari-9 Thermal Infrared Data by Applying a Physical Sea Surface Temperature Method proposes an SST-based cross-calibration which can be a fundamental technique to adjust SST with reference satellite SST and to generate consistent long-term SST datasets.
Yukio Kurihara recently shared some insights on this work. Dive into this latest publication with some key snippets below.
Motivation for this Study
This study aimed at correcting high negative bias of JAXA Himawari-9 SST that is available in GDS2.0 format via the JAXA Himawari Monitor (https://www.eorc.jaxa.jp/pgree/). An easier way to correct for bias would be a correction based on comparisons with in-situ data. However, we considered the simple bias correction spoils the essence of physical SST estimation, where JAXA’s Himawari SST is determined with an original physical method. Hence, we introduced a cross-calibration method in this study. The cross calibration has another benefit of improving the consistency of Himawari SST with the reference satellite SST.
What’s New?
The cross-calibration is an application of a physical SST method which is used for Himawari and other JAXA’s IR SST. I believe this is the first cross-calibration based on the physical SST determination from IR data.
Why It Matters?
The physical SST-based cross-calibration makes it possible to calibrate the IR bands for SST at the same time. This is beneficial in that it improves the relative accuracy between the bands (i.e., the accuracy of BTD) which is strongly related to the atmospheric correction in SST determination. The SST-based cross-calibration is robust against cloud contamination by using match-ups of satellite SSTs and buoy data because cloud contamination is easily detected by the comparison of satellite SST and buoy data.
Who Benefits?
The principle of the developed cross-calibration is beneficial for anyone developing or operating a physical SST method. This is because a similar cross-calibration would be possible using any physical SST method, not just the method JAXA applies.
The Long View
I hope the SST-based cross-calibration becomes more important in future for generating consistent SST dataset over long term.
JAXA Himawari-9 SST (https://www.eorc.jaxa.jp/ptree/index.html)
