IR Sub-Group Web Meeting 2023-09-07

GSICS Web Meeting on IR algorithms and SSU-AIRS/CrIS Merger

Agenda

1. Likun Wang (UMD): Progress of Merging SSU with AIRS/CrIS toward Extending Stratospheric Temperature Climate Data Records. (20 minutes + 5 minutes discussion)
2. Tim Hewison (EUMETSAT): Monitoring FCI calibration during MTG-I1 Commissioning with GSICS algorithms (15 minutes + 5 minutes discussion)
3. Tim Hewison (EUMETSAT): Uncertainty Analysis for the GEO-LEO IR Inter-calibration Algorithms (30 minutes + 20 minutes discussion)

Topic: GSICS IR Group Bimonthly Web Meeting

Time: Sep 7, 2023 07:00 AM Eastern Time (US and Canada)

Join Zoom Meeting
https://umd.zoom.us/j/8243989578?pwd=VnV5eWFMbUNJLzVEZGVzdnNWUm1PUT09

Meeting ID: 824 398 9578
Passcode: gsics

Attendees

Guest Chair: Likun Wang

CMA: Hanlie Xu, Hexing Wei, Zhiwei Wang

EUMETSAT: Tim Hewison, Vincent Debaecker, Ali Mousivand

JMA: Masaya Takahashi, Kazuki Kodera, Misaki Eiki

KMA: Euidong Hwang

NASA: Ben Scatino. David Doeling, Robert Levy

NOAA: Likun Wang, Fangfang Yu, Fred Wu, Siena Iacovazzi

ESA: Stefano Casadio

Martin Burgdorf, Jon Mittaz, Conor Haney

Summary

Discussion on SSU Analysis:

• How to address SSU cell leakage? Need to repeat fitting?
• CO2 in training atmospheric profiles? Need to remove CO2 trend after merging with AIRS
• Volcanic impact in record? Possible events in overlap period?

Discussion on FCI inter-calibration:

• Possible products from GEO-GEO algorithm?
  • Diurnal trend in relative bias - averaged over several days?
  • But intermediate products are helpful to diagnose calibration issues - e.g. striping
  • also important to understand influence of GEO sub-satellite positions
• IR3.8 channel definition - less sensitive to CO2 than SEVIRI?
  • also large differences in day-night inter-calibration results - may need to re-fit SBAF for day/night use?
• Will report mean bias and standard deviation over stable period during commissioning - like GSICS State of Observing System report

Discussion on Uncertainty Analysis:

• Inter-calibration results include uncertainties due to instruments L1 data, and due to the inter-calibration method
  • Uncertainty analysis addresses the latter
  • The former may be improved using inter-calibration results - including intermediate products (e.g. detector striping)
• Need to be careful about whether factors considered in uncertainty analysis are independent
  • their contributions may not be uncorrelated
• Selected approach should be applicable to broad range of GSICS algorithms
  • Particularly useful to use an ODR regression, as this allows propagation of uncertainties on both x and y
  • Should also be applicable to microwave inter-calibration - possible topic of future MWSG meeting
• May be possible to apply inter-calibraiton algorithm and uncertainty framework to synthetic observations - e.g. generated by NWP