Loop Heat Pipe Anomaly Impacts on GOES-17 ABI Bands 12 & 16

July 24, 2020

3 minute read

Background

Over the next few days, users of GOES-17 imagery from ABI Band 12 (Ozone IR) and Band 16 (Carbon Dioxide IR) will begin to notice the degradation of the imagery as a result of the seasonal loop heat pipe anomaly. As shown in Figure 1, below, the imagery will continue to deteriorate over the next several weeks until the end of August. It will quickly improve during the first week of September. The TOWR-S team will continue to provide additional updates with information on anticipated impacts as the imagery from the other infrared (IR) bands begin to degrade in the coming weeks.

Figure 1: GOES-17 Predicted Peak Longwave Infrared Focal Plane Temperature

Figure 1, above, shows daily maximum temperature of the ABI focal plane module. These maximums occur at night. The higher the temperature, the more saturated imagery becomes. Where the temperature rises to approach a black line for each band, marginal saturation may be observed in imagery. Where the temperature curve exceeds a black line for each band, the imagery may begin to saturate so much that it becomes unusable.

 

Anticipated Band 12 Impacts

A visual representation of the anticipated daily impacts for Band 12 can be found here and in Figure 2, below. A yellow cell with a "1" indicates estimated minimal to moderate degradation in the imagery for a given hour on a given day. Similarly, a red cell with a "2" indicates estimated severe degradation to the point that the imagery becomes unusable. The hour of day is at the top along the horizontal axis in UTC. The date is to the left along the vertical axis in ascending order.

Figure 2:  Anticipated impacts for Band 12 from July 24 - September 7

​​In Figure 2, above, the horizontal axis ranging from 0 to 23 (top) is the hour of the day in UTC
and the vertical axis is the calendar date from July 24 to September 7, 2020 in ascending order.​

The table below includes the GOES-17 data products that will be impacted by the degradation of Band 12. A quick guide for each data product is linked in the right column.

Data Product Link to Quick Guide
Airmass RGB CIMSS Quick Guide for Airmass RGB
Derived Stability Indices CIMSS Quick Guide for Derived Stability Indices
Legacy Vertical Moisture and Temperature Profiles CIRA Quick Guide for Legacy Vertical Profiles
Split Ozone Brightness Temperature Difference CIMSS Quick Guide for Split Ozone Brightness Temperature Difference
Total Precipitable Water CIRA Quick Guide for Total Precipitable Water

 

Anticipated Band 16 Impacts

A visual representation of the anticipated daily impacts for Band 16 can be found here and in Figure 3, below. A yellow cell with a "1" indicates estimated minimal to moderate degradation in the imagery for a given hour on a given day. Similarly, a red cell with a "2" indicates estimated severe degradation to the point that the imagery becomes unusable. The hour of day is at the top along the horizontal axis in UTC. The date is to the left along the vertical axis in ascending order.

Figure 3:  Anticipated impacts for Band 16 from July 24 - September 7

​​In Figure 3, above, the horizontal axis ranging from 0 to 23 (top) is the hour of the day in UTC
and the vertical axis is the calendar date from July 24 to September 7, 2020 in ascending order.

The table below includes the GOES-17 data products that will be impacted by the degradation of Band 16. A quick guide for each data product is linked in the right column.

Data Product Link to Quick Guide
Cloud Top Height CIMSS Quick Guide for Cloud Top Height
Cloud Top Pressure CIMSS Quick Guide for Cloud Top Pressure
Cloud Top Temperature CIMSS Quick Guide for Cloud Top Temperature
Derived Stability Indices CIMSS Quick Guide for Derived Stability Indices
Legacy Vertical Moisture and Temperature Profiles CIRA Quick Guide for Legacy Vertical Profiles
Total Precipitable Water CIRA Quick Guide for Total Precipitable Water

 

More Information on the Loop Heat Pipe Anomaly

For additional information regarding this seasonal loop heat pipe anomaly event, including the upcoming supplemental GOES-15 operations and the GOES-17 Mode 3 cooling timeline operations, refer to the article linked here. Mark your calendars for August 20th when Dave Pogorzala from the GOES-R Program will be presenting in the Satellite Book Club on the loop heat pipe anomaly. Stay tuned for more details on that session!