Using CSPP Quicklooks software to show multiple NUCAPS passes

August 31st, 2022 |
Suomi-NPP NUCAPS estimates of 300-mb temperature, 15-20 October 2018 (click to enlarge)

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.

Suomi-NPP NUCAPS profiles temperatures at 300 mb, ca. 1700 UTC on 19 October 2018 (Click to enlarge)
Suomi-NPP NUCAPS profiles temperatures at 300 mb, ca. 1900 UTC on 19 October 2018 (Click to enlarge)

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.

Improvements to the CSPP Geosphere website

August 4th, 2022 |
Nighttime Microphysics RGB over the upper Midwest, 0721 to 0816 UTC on 4 August 2022

The CSPP Geosphere website has recently been upgraded. CSPP Geosphere uses data from the GOES Re-Broadcast (GRB) data stream Those data are processed on an on-site Kubernetes cluster that produces full-resolution GOES-East/GOES-West images that are quickly and fluidly zoomable and pannable. In addition, recent software and hardware upgrades mean that processing is faster. GOES-West data (either GOES-17 or GOES-18 during interleave periods such as the one occurring from early August until 6 September 2022) are now available. The default imagery shown remains Nighttime Microphysics RGB at night, as shown above, and sharpened, Rayleigh-corrected True-Color imagery during the day (as shown in the image below).

CSPP Geosphere allows users to save off mp4 videos of animations as shown above (with the default number of frames, 12, although any number of frames can be displayed in an animation), and also individual png frames, as shown below. The mp4 animations and individual png frames are created on the client machine; creation speed will depend on a user’s computer’s resources and resolution. In addition, the site now includes a default lat/lon readout that tracks the cursor, and a searchbox that will allow a user to center the image near a location at near-maximum zoom (‘Manhattan’, for example, as shown below — after zooming out one step). Latitude/Longitude and Coastlines/Borders can be turned on and off.

CSPP Geosphere rendering of true-color imagery over New York City, 1340 UTC on 4 August 2022 (Click to enlarge)

The example below shows 48 frames of GOES-18 data over the northern Pacific Ocean (link; CSPP Geosphere lets users easily share the url used to create the imagery). Note the abundant smoke over the central USA at the end of the animation, and the sun glint over Asia at the start. Barcode noise (also here) in Band 7 (a component of the Nighttime Microphysics RGB) is apparent, but faint.

GOES-18 Night Microphysics/True Color combination, 0530 – 1320 UTC on 4 August 2022

GOES-16 Imagery, below (from this CSPPGeosphere link) shows the turbid waters of the Amazon flowing northward into the tropical Atlantic.

GOES-16 True Color imagery, 1110-1340 UTC on 4 August 2022

The GeoSphere website and back end were created using SSEC-internal funds. The CSPPGeo GOES Re-Broadcast (GRB) processing software and CSPPGeo Geo2Grid software used in the back end were created with funding from NOAA.

Using Polar2Grid and NOAA CLASS VIIRS data to create imagery

April 1st, 2022 |
NOAA-20 I05 (11.45 µm) imagery over the Arctic Ocean, 1455-1510 UTC on 1 February 2022 (Click to — greatly!! — enlarge)

Previous blog posts (example) have documented how to create imagery from the VIIRS instrument, and this one is another example. For example, if you receive a request for VIIRS imagery such as this one: “If you have time to try a case, you could pick Feb 1, 2022 near North Pole Point for 11 um channel” — how do you proceed? A first step is to determine the day/time of the data, and that’s achieved by looking at orbits over the Arctic, at this website. That website also has an archive, and the archive for Arctic passes on 1 February 2022 is here. The image shows NOAA-20 passing over Greenland, the Arctic Ocean, and then moving over eastern Russia between 1455 and 1510 UTC on 1 February 2022. Now you know the times to request.

NOAA CLASS is the data repository that stores VIIRS imagery from NOAA-20 and Suomi-NPP. Go to the website, an log in (register if you have not already), and choose JPSS VIIRS SDRs (Operational Sensor Data Records) as shown below. Choosing those data and clicking >>GO to the right of the drop-down menu bar will move you to a new data-selection menu, where you will select the day/time of the data (1 February 2022, 14:55 Start time, 15:10 end time), and the band (I chose SVI05 — the 11.45 µm Imager channel, with 375-m resolution, that is: VIIRS Imagery Band 05 SDR (SVI05) (public 02/07/2012) ), and the satellite (NOAA-20). Geolocation data must also be selected, and Polar2Grid will expect the GITCO files. Choose them ( VIIRS Image Bands SDR Ellipsoid Terrain Corrected Geolocation (GITCO) (public 02/07/2012)) as well. It is very important, however, that your User Preferences are configured so that the data are disaggregated! Click on User Preferences, and make that selection. The User Preferences page should include information as shown here.

NOAA CLASS front page showing the VIIRS data to select (Click to enlarge)

The steps above will produce 12 matches — 6 files of SVI05 and 6 GITCO files. Submit your order and wait for the email notification that the files are ready. While you are waiting, if you’ve not done so already, download the Polar2Grid software from CIMSS CSPP Site (CSPP: Community Satellite Processing Package; note that a free registration might be required). Expand the downloaded (compressed tar) file into an empty directory, and enter this unix command: export POLAR2GRID_HOME=/directory/where/the/expanded/file/sits.

NOAA CLASS will send an email once the data are staged and ready for you. Download those data, and then enter this command:

sh ./polar2grid.sh viirs_sdr gtiff -p i05 -g polar_canada -f /directory/holding/downloaded/SVI05Data/SVI05* /directory/holding/downloaded/GITCOdata/GITCO*

That code takes the viirs_sdr and GITCO data pointed to by the -f flag and creates a geotiff of i05 (11.45) imagery. Because these data are near the Pole, I’ve specified a grid (‘-g polar_canada’) to be used (a full list of pre-defined grids is here, part of the Polar2Grid online documentation). The command will stitch together the data in the 6 different files, and you’ll see an image at full resolution, as shown above. I also used software to add coastlines and lat/lon (‘grid’) lines.

sh ./add_coastlines.sh --add-grid --grid-D 10 10 --grid-d 10 10 --add-coastlines noaa20_viirs_i05_20220201_145336_polar_canada.tif

The coming geo2grid update will include level 2 product support

March 21st, 2022 |
Cloud-top Height, 1510 UTC on 21 March 2022 (click to enlarge)

As noted here, an updated version of geo2grid is being prepared at CIMSS. As part of that upgrade, support for some level 2 products will be included. For example, the image above — of cloud-top height — was created using the following set of geo2grid (a beta version that this blogger is testing) calls.

./geo2grid.sh -r abi_l2_nc -w geotiff -p HT -g L2Fields --grid-configs $GEO2GRID_HOME/L2Fields.yaml --method nearest --radius-of-influence 40000 -f /arcdata/goes_restricted/grb/goes16/2022/2022_03_21_080/abi/L2/ACHAC/*s20220801501*.nc
../add_coastlines.sh --add-coastlines --coastlines-resolution h --coastlines-level=5 --coastlines-outline='blue' --add-grid --grid-text-size 0 --grid-D 5.0 5.0 --grid-d 5.0 5.0 --add-colorbar --colorbar-align right --colorbar-text-size 8 --colorbar-vertical --colorbar-no-ticks --add-borders GOES-16_ABI_HT_20220321_150116_L2Fields.tif
convert GOES-16_ABI_HT_20220321_150116_L2Fields.png -gravity Southwest -fill black -pointsize 16 -annotate +12+36 "GOES-16 Cloud Top Height 1501 UTC 21 March 2022" GOES-16_ABI_HT_20220321_150116_L2Fields1.png
convert GOES-16_ABI_HT_20220321_150116_L2Fields1.png ~scottl/smalllogo.png -gravity northwest -geometry +12+8 -composite GOES-16_ABI_HT_20220321_150116_L2Fields2.png

How does the image above compare to Level 2 product fields that can be found elsewhere? This website contains a link to a RealEarth instance that includes mappings of Full-Disk Cloud Mask, Cloud Top Pressure, Cloud top Phase, and Cloud Optical Depth. A portion of the Full-Disk Cloud Top Pressure is shown below (from 1500 UTC). Similar features are apparent in fields above and below.

GOES-16 Cloud Top Pressure, 1500 UTC on 21 March 2022 (click to enlarge)

Level 2 Products associated with Cloud-top properties are also available at the CIRA slider, including Cloud-top Height, shown below from 1501 UTC. Other GOES-R Level 2 products available there include Cloud Optical Depth, Cloud Mask, Cloud Phase and Cloud Effective Particle Size.

GOES-16 Cloud-top Height, 1501 UTC on 21 March 2022 (click to enlarge)