Using CSPP Quicklooks software to show multiple NUCAPS passes
CSPP Quicklooks (click to view documentation) is a software package (available here) developed at CIMSS to (as the name might suggest!) create images from Polar-orbiting data, as shown in this blog post that shows imagery created from Direct Broadcast data (for example. using NUCAPS EDRs (Environmental Data Records) files as available at the CIMSS Direct Broadcast site). NUCAPS EDR files can also be downloaded from the NOAA CLASS site — by choosing ‘JPSS Sounder Products’ in the ‘Please select a product to search’ drop-down menu, and then choosing ‘NUCAPS Environmental Data Records’ — that is, EDRs.
Follow the instructions in this blog post to download and set up the Quicklooks software (free registration at the CSPP website may be required). Imagery at the previous blog post used default domains and colorbars. In the example above, multiple images are captured over a specified domain, and are scaled identically using keywords as shown in the calls below:
file18=$CSPP_SOUNDER_QL_HOME/data4/NUCAPS-EDR_v2r0_npp_s2018101917*.nc
sh ./ql_level2_image.sh "$file18" NUCAPS --dset temp --pressure 300 --plotMin 223.0 --plotMax 258.0 --lat_0 15.0 --lon_0 -75.0
Note that ‘file18’ identifies all files within a directory that contain an EDR from around 1700 UTC on 19 October 2018. The wildcard includes >20 different granules that are composited into an image for that time, as shown below. The –plotMin and –plotMax keywords define the color scaling used, and the data are centered at 15o N, 75o W on a Lambert Conformal grid. Similarly, an image that uses all data from 20181919* can be created, as shown below.
How are both images combined so that data from the afternoon/evening passes are in one image (as shown in the animation above?) This is done by making parts of the images above transparent, and by overlaying the transparent image over the bottom image (I did this using ImageMagick). Both white (“#ffffff”) and grey (“#d9d9d9”) values were made transparent, and a combined image (here) is created. This is done for all morning images, and afternoon/evening images, and the animation is then created.
Note that if this is done when both Suomi-NPP and NOAA-20 passes are available, the gaps apparent in the imagey above will not be present. October 2018 was before NOAA-20 NUCAPS were operational however.