The NOAA Open Data Dissemination (NODD) resource (more information at this link) provides global data from JPSS. One source from which data are available is Amazon Web Services, with separate portals for Suomi NPP, for NOAA-20 and for NOAA-21. The data at those sites are arranged by times; step one for data acquisition/imagery creation will be: how do I find the time of the data that I want? Time-stamped polar orbit tracks for many satellites are available at the SSEC Polar Orbit Tracker. For this exercise, I’ve decided to plot imagery over Oman, using data from Suomi-NPP, from 11 July and 12 July 2023. These two orbital path plots are also shown below, side-by-side. Based on these plots, data 2215 to 2220 UTC on 11 July, and from 2156 to 2201 UTC on 12 July, are needed. As expected, the orbit on 12 July is a bit earlier, and a bit farther east, than the orbit on 11 July.

The front page of the Amazon Web Services data portal (url) is shown below. Various data sources are indicated, and the ones relevant for Day Night Band imagery, the Sensor Data Record (SDR) and the geolocation data, are highlighted. Clicking on those two links will lead you down through dates: first, the year (2023), then the month (07), then the days (11 and 12) of the month.

At the AWS website, the files highlighted below can be found within the VIIRS-DNB-SDR file structure highlighted above. The 4 files cover the time from 2156 UTC through 2201 UTC on 12 July. Four files covering the same time must also be retrieved from the VIIRS-DNB-GEO directories (so that Polar2Grid can georeference the imagery).

The 8 files, 4 SDR files, and 4 Geolocation files, were downloaded into a single directory ($POLAR2GRID_HOME/bin/Oman/12July/) and are shown below. Data for the first granule starts at 21:56:05.6 ; data for the last granule ends at 22:01:46.0. Compare these times to the predicted orbit path for 12 July.

GDNBO_npp_d20230712_t2156056_e2157298_b60659_c20230712231823180765_oeac_ops.h5
GDNBO_npp_d20230712_t2157310_e2158552_b60659_c20230712231840091446_oeac_ops.h5
GDNBO_npp_d20230712_t2158564_e2200206_b60659_c20230712231842198229_oeac_ops.h5
GDNBO_npp_d20230712_t2200218_e2201460_b60659_c20230712231840745234_oeac_ops.h5
SVDNB_npp_d20230712_t2156056_e2157298_b60659_c20230712231944635733_oeac_ops.h5
SVDNB_npp_d20230712_t2157310_e2158552_b60659_c20230712232005061889_oeac_ops.h5
SVDNB_npp_d20230712_t2158564_e2200206_b60659_c20230712232018004433_oeac_ops.h5
SVDNB_npp_d20230712_t2200218_e2201460_b60659_c20230712232018845500_oeac_ops.h5

What kind of products will Polar2Grid create given these input fields? The –list-products-all flag shows that, that is: $POLAR2GRID_HOME/bin/polar2grid.sh -r viirs_sdr -w geotiff --list-products-all -f $POLAR2GRID_HOME/bin/Oman/12July/*.h5, which yields the list below.

adaptive_dnb
dnb_lunar_azimuth_angle
dnb_lunar_zenith_angle
dnb_sat_azimuth_angle
dnb_sat_zenith_angle
dnb_solar_azimuth_angle
dnb_solar_zenith_angle
dynamic_dnb
dynamic_dnb_saturation
histogram_dnb
hncc_dnb

Several different types of Day Night Band products are available; I chose dynamic_dnb because it looked best for this day, and command used was $POLAR2GRID_HOME/bin/polar2grid.sh -r viirs_sdr -w geotiff -p dynamic_dnb -f $POLAR2GRID_HOME/bin/Oman/12July/*.h5 ; that yields a geotiff file; $POLAR2GRID_HOME/bin/add_coastlines.sh --add-coastlines --add-grid --grid-D 5.0 5.0 --grid-d 5.0 5.0 npp_viirs_dynamic_dnb_20230712_215731_wgs84_fit.tif adds georeferencing — coastlines and latitude/longitude lines, and writes out a png file that is shown at the top of this blog post. A similar set of commands produced the image from 11 July 2023 over about the same region, shown below.

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What if you want to see how things change in a region from one image to the next? That is complicated if you look at the native projections as shown above. However, Polar2Grid allows you to re-grid data onto a pre-defined grid that you can easily create with the a built-in script: $POLAR2GRID_HOME/bin/p2g_grid_helper.sh Oman 57.0 23.0 500.0 -500.0 1440 1020 > $POLAR2GRID_HOME/bin/Oman/Oman.yaml ; this command defines the ‘Oman’ grid, centered at 57^oE, 23^oN, with grid-spacing of 500 m in the west-east and north-south directions. The grid size is 1440×1020. The Polar2Grid calls to make the output, and to add coastlines and latitute/longitude grids are shown below. These scripts all sit within the $POLAR2GRID_HOME/bin directory.

$POLAR2GRID_HOME/bin/polar2grid.sh -r viirs_sdr -w geotiff -p dynamic_dnb -g Oman --grid-configs $POLAR2GRID_HOME/bin/Oman/Oman.yaml -f $POLAR2GRID_HOME/bin/Oman/11July/*.h5
$POLAR2GRID_HOME/bin/polar2grid.sh -r viirs_sdr -w geotiff -p dynamic_dnb -g Oman --grid-configs $POLAR2GRID_HOME/bin/Oman/Oman.yaml -f $POLAR2GRID_HOME/bin/Oman/12July/*.h5
$POLAR2GRID_HOME/bin/add_coastlines.sh --add-coastlines --add-grid --grid-D 5.0 5.0 --grid-d 5.0 5.0 --grid-text-size 20 npp_viirs_dynamic_dnb_20230711_221501_Oman.tif
$POLAR2GRID_HOME/bin/add_coastlines.sh --add-coastlines --add-grid --grid-D 5.0 5.0 --grid-d 5.0 5.0 --grid-text-size 20 npp_viirs_dynamic_dnb_20230712_215605_Oman.tif

I annotated the png files created by the two add_coastlines.sh invocations above, and the result is shown below in a toggle. The moon on these two days was not providing illumination, but clouds can still be viewed over the bright lights of Oman and the United Arab Emirates.

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The University of Wisconsin-Madison’s SSEC Satellite Data Services added NOAA GOES SUVI (Solar UV Imager) images, both GOES-16 and GOES-18 (pulldown menu names: SUVI GOES-18 and SUVI GOES-18) to the Geo-Browser. More on SUVI can be found at NOAA’s Space Weather Prediction Center or this site. The Geo-browser SUVI page allows for longer loops, RGB composites, and being able to save the animation.

Single Bands

There are six spectral bands on the SUVI; this table from the Volume 3 PUG shows the various uses. These images, built from the GRB data stream, include the six spectral bands.

Loops (mp4) of the other SUVI bands: 1, 2, 4, 5 and 6. As well as still image bands 1, 2, 3, 4, 5 and 6.

RGB Composites

Several of the single spectral bands are combined to generate 3-band Red-Green-Blue image composites. The web page has four RGB combinations (scroll to the bottom of the “Channel” list).

A toggle between a RGB view from GOES-16 and -18.

For those interested in generating unique SUVI RGB combinations, one can experiment with near realtime data and several cases.

H/T

Thanks to the UW SSEC Satellite Data Services (SDS) Team, the CSPP Geo Team, as well as the makers of the HereGOES software.

More on the GOES-R series, including imagery, data and information.

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1-minute Mesoscale Domain Sector GOES-16 (GOES-East) Nighttime Microphysics RGB images (above) included plots of Local Storm Reports — which showed a thunderstorm that produced wind-driven hail as it moved across northeastern Wyoming during the late afternoon and evening hours on 11 July 2023. Note the long, narrow swath of colder surface temperature (shades of beige) in the wake of the thunderstorm, which was likely a signature of hail accumulation. Hail in Wyoming was as large as 2.50 inches in diameter, with wind gusts to 58 mph (SPC Storm Reports)..

On the following day, GOES-16 True Color RGB images from the CSPP GeoSphere site (below) highlighted the NW-to-SE oriented hail damage swath — which showed up as lighter shades of tan (in contrast to the shades of green associated with healthy, undamaged vegetation and cropland).

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The third named storm of the Eastern Pacific tropical season has formed. (Click here for NHC‘s public advisory on the naming of Calvin) The mp4 animation above (click here for an animated gif) shows the evolution of the system for the 24 hours ending at 1210 UTC on 12 July as it gradually acquired rotation, evolving from a large convective complex at the start of the animation while it traveled over very warm waters.

1-minute Mesoscale Domain Sector GOES-18 Infrared and Visible images (above) showed the period from 0900-1500 UTC (1315-1500 UTC for the Visible imagery), as Tropical Depression Three-E intensified along the Monsoon Trough to become Tropical Storm Calvin. A few convective bursts were evident near the storm center, with overshooting tops exhibiting infrared brightness temperatures as cold as -86ºC at 1441 UTC.

Calvin is now in a favorable environment for strengthening. The toggle below (using imagery from this website) shows the forecast path, the sea-surface temperatures, and the diagnosed atmospheric shear.

Abundant moisture surrounding Calvin is depicted in the MIMIC Total Precipitable Water animation shown below. The circulation of Calvin is apparent just west of 110^oW Longitude.

Atmospheric steering flow, shown below as the 850-500mb mean layer wind, takes the system on a westerly course. Long-range forecasts have the system (or its remnant moisture) affecting the Hawai’ian islands in the middle of next week. The movement and evolution of anticyclones to the northeast and northwest of Hawai’i shown below will be steering Calvin as that happens.

 

For the latest on Calvin, refer to the webpages of the National Hurricane Center.

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