CIMSS-NOAA Weekly Report [ Archive ]

CIMSS-NOAA WEEKLY HIGHLIGHTS FOR THE WEEK ENDING OCTOBER 3, 2025

DATA, INFORMATION, AND USE-INSPIRED SCIENCE:

CIMSS develops new enhanced AMSR2 sea ice concentration product for forecasters: With support from the Joint Polar Satellite System (JPSS) Proving Ground and Risk Reduction (PGRR) Program, a new Advanced Microwave Scanning Radiometer-2 (AMSR2) sea ice concentration (SIC) product has been developed based on enhanced resolution (3.125 km) AMSR2 89 GHz imagery. In comparison to the standard NOAA 10 km AMSR2 SIC product, the new product reveals narrow leads and provides significantly more detail in the pack ice to give additional information to Alaska Sea Ice Program (ASIP) forecasters for decision support and ice analysis. (T. Greenwald, CIMSS, 608-263-3629, Y. Liu, E/RA2, 608-890-1893, yinghui.liu@noaa.gov)

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Figure: Comparison of NOAA 10 km AMSR2 SIC product (left) and 3.125 km AMSR2 SIC product (right) over the Alaska region, 11 May 2023.

Cross-track Infrared Sounder Single Scan Line Calibration at CIMSS: Relatively large calibration artifacts are observed for the NOAA-21 Cross-track Infrared Sounder (CrIS), for limited parts of descending orbits immediately after the spacecraft exits solar eclipse. These artifacts are not observed for prior CrIS instruments and are likely associated with changes to spacecraft nadir deck configuration for NOAA-21. In the past years significant progress has been made by the CrIS Sensor Data Record (SDR) team to characterize these effects and to identify a change to the calibration process to remove the artifacts, which is important not only for NOAA-21 but also JPSS-4 and JPSS-3 which are anticipated to have similar behavior but with unknown magnitude. Team members at the Cooperative Institute for Meteorological Satellite Studies have proposed and investigated a Single Scan Line (SSL) calibration approach utilizing Principal Component (PC) noise filtering of calibration to mitigate the effects. This approach increases the temporal frequency of the calibration such that rapid changes in the sensor complex responsivity during eclipse-exit are accurately captured. The SDR team then developed a plan to modify the operational calibration algorithm utilizing the SSL approach. CIMSS contributed to this effort by assessing and developing components of the SSL algorithm, including assembling training data of ICT and Deep Space view interferograms and assessing different methodologies for PC filtering of these data on a SSL basis, including the consideration that there are fringe count differences when the sensor is restarted. An initial prototype software package, including initial PC data and SSL PC algorithm description, was provided in April. More recently we have implemented the prototype algorithm and processed the full NOAA-21 mission with the SSL calibration. The results are encouraging with various evaluation results demonstrating that the eclipse-exit calibration artifacts are reduced to below noise level. An example result is shown in the figure below, where imaginary radiances for a spectral region sensitive to this effect are plotted as a function of satellite solar zenith angle for each Field-Of-View (FOV) for data collected on 23 February 2023. For typical operations the imaginary component of the calibrated radiance is representative of the sensor noise, but can also be indicative of calibration artifacts if present. The left-hand panels show large imaginary radiances for solar zenith angles during and after eclipse exit, when using the traditional calibration approach, while the right-hand panels show that these artifacts are removed when using the new SSL approach. Next steps for the SDR team include incorporating the new algorithm into the Algorithm Development Library (ADL) package, creating sample datasets using the ADL implementation of the SSL calibration, and testing and evaluating the data by SDR, retrieval, and Numerical Weather Prediction groups. (D. Tobin, CIMSS, 608-265-6281) 

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Figure: NOAA-21 CrIS Imaginary component radiance on 23 Feb 2023 for the 2320 1/cm spectral region as a function of satellite solar zenith angle with respect to spacecraft heading for each FOV using the current/traditional calibration approach (left-hand panels) and using the new SSL calibration approach (right-hand panels).

PEOPLE, AWARDS AND RECOGNITION:

TRAVEL AND MEETINGS:

TRAINING AND EDUCATION:

Public presentation about SSEC/CIMSS and satellites in Oshkosh, WI : Steve Ackerman gave a public talk on "5 ways UW satellite tech helps save lives." The invitation for a presentation followed from a UW-Madison story about the work of CIMSS and SSEC. There were appoximately 20 people in attendance; the talk was also recorded for broadcast on the local public station. (Steve Ackerman, CIMSS) 

MEDIA INTERACTIONS AND REQUESTS:

SOCIAL MEDIA AND BLOG Posts:

CIMSS Satellite Blog Updates: The Cooperative Institute for Meteorological Satellite Studies (CIMSS) Satellite Blog (https://cimss.ssec.wisc.edu/satellite-blog/) was updated with the following posts: "Hurricane Humberto reaches Category 5 intensity in the western Atlantic" (Sep. 27) and "Category 2 Hurricane Imelda passes over Bermuda" (Oct. 1). (S. Bachmeier, CIMSS)

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Figure: GOES-19 Infrared image showing the eye and eyewall of Hurricane Humberto as it was rapidly intensifying from a Category 4 to a Category 5 storm over the western Atlantic Ocean at 1812 UTC on September 27, 2025.

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