Gridded NUCAPS fields are available in AWIPS

October 29th, 2019 |

NUCAPS Sounding Availability points from AWIPS, 1304 UTC on 29 October 2019, and the Temperature at 500 hPa at the same time (Click to enlarge)

Gridded NUCAPS fields (Here’s a NASA SpoRT VLab page on the product) are now available in AWIPS, effective with AWIPS Build 19.3.1. The imagery above includes a swath of NUCAPS points (called up via ‘NUCAPS Sounding Availability’) under the Satellite Tab, and the ‘S-NPP and NOAA-20’ choice there (even though, at present, only NOAA-20 NUCAPS profiles are supplied to AWIPS). A ‘Gridded NUCAPS’ choice is available right about the NUCAPS Sounding Availability, and this allows a user to choose Temperature, Dewpoint Temperature, Equivalent Potential Temperature, Lapse Rates (and more!) at different standard mandatory pressure levels (or layers, for Lapse Rates). Interpolation in the vertical has moved the native NUCAPS pressure levels (mentioned here) to standard pressure levels.

The plot above also shows the temperature at 500 hPa for the same time, 1304 UTC.  Gridded NUCAPS fields do not cover the entire extent of the NUCAPS Sounding Availability plots.  In addition, values are present for all sounding color dot points — green, yellow and red — on the theory that a user can identify the bad data visually.

The animation below shows a series of gridded fields over northern Canada, covering much of the the Sounding Availability plot.  Because of the timestamps on these different grids, they do not all time match the swath of NUCAPS Sounding Availability points. On this day, the size of some of the fields produced was quite small.  The size of the gridded region is limited by computational resources on AWIPS, and the upper limit is 20 lines of NUCAPS soundings — 600 soundings total that are horizontally and vertically interpolated. The size is also affected by the order in which the soundings appear in AWIPS. If a small chunk (say, 7 lines of soundings) comes in, then that small chunk will be processed into a horizontal grid. It’s more common that grid sizes will be closer to what occurred at 1304 UTC.

Temperature at 500 mb from NUCAPS Soundings, 1304 – 1311 UTC on 29 October 2019 (Click to enlarge)

If you look in the Product Browser on AWIPS, you will find far more data than are available under the ‘Gridded NUCAPS’ menu under ‘NOAA-20 and S-NPP’ under the satellite tab.  (Here’s just a small sample!)  For example, you can plot Ozone estimates from NUCAPS, as shown below — loaded as a grid then converted to an image.  Expect the presentation of NUCAPS horizontal fields in AWIPS to evolve with time.  In the meantime, this is a valuable data set to determine (for example) the likelihood of snow v. rain based on the 925 Temperature and Dewpoint Depression.

AWIPS Product Browser showing Ozone Estimates at 1304 UTC on 29 October 2019 (Click to enlarge)

(Thanks to Dr. Emily Berndt, NASA SpoRT, for clarifying remarks. Any errors that remain are the author’s, however!  Imagery courtesy NWS MKX)

GOES-16 ABI Derived Products such as Cloud-top Phase in AWIPS

August 14th, 2019 |
AWIPS

AWIPS image of the Contiguous US domain showing the ABI 3.9 µm (on the left portion of the image and the ABI 1.6 µm (on the right portion of the image). The readout of the Level 2 cloud-top phase is also displayed.

The above animation shows the ABI 3.9 µm band for regions of less solar illumination and the ABI 1.6 µm “snow/ice” band for regions more fully illuminated. Also shown is a readout of the GOES-16 cloud-type phase product for a point in eastern Texas. Note how the estimates range for this location from clear sky, liquid water, mixed phase and super-cooled droplets. This shows one example of how to use imagery in conjunction with derived products. These images where generated in AWIPS using a procedure.

Cloud-top phase can be found in RealEarth (search on ‘phase’), GEOCAT (direct link to cloud-top type), and the GOES-R cloud page. An archive of netCDF are held in NOAA’s CLASS.

There are many “Level 2” or derived products generated from the ABI radiances. These include, but are not limited to: cloud proprieties, atmospheric motion, fire, stability, sea and land surface temperatures. More information on these products can be found on the Algorithm Working Group web page, product quality web page or these links.

AWIPS image

AWIPS image of the Contiguous US domain showing the ABI 3.9 µm (on the left portion of the image and the ABI 1.6 µm (on the right portion of the image). The readout of the Level 2 cloud-top phase is also displayed.

True-Color RGBs with GOES-16 Data

June 15th, 2017 |

GOES-16 ABI True-Color RGB over the Northern Hemisphere, 2030 UTC on 15 June 2017 (Click to enlarge)

GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing

True-Color Imagery can be computed quickly in AWIPS using several simple xml files and Python code. An example is shown above. The Green Band that is missing from the ABI is simulated using a combination of the Blue Visible (0.47 µm), Red Visible (0.64 µm), and Veggie Bands (0.86 µm), and that simulated Green is then combined with the Blue and Red bands to create the imagery seen above. Some modest stretching is done to enhance contrast.

GOES-16 Resolution in southern Canada with AWIPS

March 3rd, 2017 |

AWIPS Displays of GOES-16 Visible (0.64 µm) imagery at 1511 UTC (CONUS) and 1510 UTC (Full Disk) (Click to enlarge)

Note: GOES-16 data shown on this page are preliminary, non-operational data and are undergoing on-orbit testing.

GOES-16 data that flow into AWIPS for Full Disk display are not at Full Resolution; rather, they are degraded to approximately 6-km resolution. The northern boundary of the GOES-16 ‘CONUS’ domain (GOES-16 data do flow into AWIPS at full resolution for this domain) is very close to the US-Canada border (as shown in this animation of all 16 bands from this blog post, and also in the animation above). When zoomed out, there is little apparent difference in the two images. If you zoom in, however, as shown below with Band 2 (0.64 µm) imagery, the seam between the two resolutions is very noticeable.

GOES-16 Visible Imagery, 1925 UTC, over southern Canada and northern Minnesota/North Dakota (Click to enlarge)

The change in resolution occurs for all bands. The 10.3 µm imagery, below, shows the change north of Montana, Idaho and Washington.

ABI Band 13 (10.3 µm) Imagery at 1510 UTC in the AWIPS CONUS domain (full resolution) and in the AWIPS Full Disk Domain (reduced resolution). (Click to enlarge)