Starting in July 2010, CIMSS began making a variety of CLAVR-x based POES AVHRR derived products (see menu above) as well as POES AVHRR individual channel images (see menu below) available for NWS offices to add to their local AWIPS workstations via LDM subscription (see the AVHRR Imagery and Products in D-2D site for installation instructions). A VISIT training lesson “POES and AVHRR Satellite Products in AWIPS” is available to help users understand the interpretation of the various images and products, with some examples of their application to weather analysis and forecasting.
A few AWIPS examples of these POES AVHRR products and images are shown below, as they appear in various posts on the CIMSS Satellite Blog (for the complete library of cases, see the “AVHRR” blog category):
AVHRR Band 1 Visible Channel (0.63 Âµm)
The wave structure of an undular bore was well-depicted on the POES AVHRR 0.63 Âµm visible image (below) as the feature was propagating southeastward over the Gulf of Mexico on 27 April 2011. Overlays of hourly MADIS atmospheric motion vectors (or cloud-tracked winds) showed that the undular bore was moving southeastward at a speed of 20-30 knots.
AVHRR Band 2 Visible Channel (0.86 Âµm)
A series of von Karman vortices was seen on POES AVHRR 0.86 Âµm visible channel imagery (below), streaming south of the Aleutian Islands of Alaska on 14 April 2011. In addition, the ice that remained farther to the north in the Bering Sea was also very evident.
AVHRR Band 3B Shortwave IR Channel (3.74 Âµm)
A large number of “hot spots” (black to red to yellow color enhancement) could be seen on a POES AVHRR 3.74 Âµm shortwave IR image (below) due to widespread fires that were burning across eastern Oklahoma on 11 March 2011.
AVHRR Band 4 IR Window Channel (10.8 Âµm)
POES AVHRR 10.8 Âµm IR images (below) showed that Hurricane Tomas was exhibiting IR brightness temperatures as cold as -93Âº C (darker purple color enhancement) as the storm passed between Jamaica and Hispaniola on 05 November 2010. A distinct “transverse banding” signature was also seen to develop along the western and southwestern periphery of the cloud shield — this satellite signature is an indicator of potential turbulence.
AVHRR Band 5 IR Channel (12.0 Âµm)
A POES AVHRR 12.0 Âµm IR image (below) very close to the time that a tornado was moving through the St. Louis area is shown with an overlay of the SPC hail, damaging winds, and tornado reports. Note that the storm exhibited a very well-defined â€œenhanced-vâ€ signature near St. Louis (with a minimum cloud top IR brightness temperature of -83Âº C) â€” this enhanced-v IR storm top signature is often observed with areas of strong convection that are producing (or are about to produce) either large hail, damaging winds, or tornadoes.
Individual POES AVHRR channels can be combined to create Red/Green/Blue (RGB) images that might be helpful to differentiate between different cloud features or cloud layers. The false color RGB image below uses POES AVHRR channels 1, 2, and 4 as the Red, Green, and Blue components to show the clouds associated with a storm system over the eastern US on 26 January 2011. High-level clouds appear brighter white, while low-level clouds take on more of a pale yellow shade; vegetated land surfaces appear green, while water appears blue.
AVHRR Fog Product
A comparison of the 1-km resolution POES AVHRR fog/stratus product with the corresponding 4-km resolution GOES-13 fog/stratus product (below) demonstrates the advantage of improved spatial resolution to aid in the detection of small scale river valley fog features across the central Appalachian Mountains region on 08 October 2010.
AVHRR Sea Surface Temperature Product
AVHRR Sea Surface Temperature product (below) showing that an oil slick (resulting from the Deepwater Horizon oil rig fire and collapse) was exhibiting SST values that were several degrees cooler (green color enhancement) than the surrounding waters in the northern Gulf of Mexico on 29 April 2010.
AVHRR Cloud Type Product
The POES AVHRR Cloud Type product can be used to discriminate between water droplet clouds, supercooled water droplet clouds, opaque ice crystal clouds, cirrus clouds, or clouds that are likely overshooting the tropopause. An example of the Cloud Type product (below) is shown for a strong storm off the coast of the northeastern US, which produced heavy rain, heavy snow, and high winds across parts of that region on 08 November 2010.
AVHRR Cloud Top Temperature Product
An example of the POES AVHRR Cloud Top Temperature product is shown below for the same strong storm off the coast of the northeastern US.
AVHRR Cloud Height Product
An example of the POES AVHRR Cloud Top Height product is shown below for the same strong storm off the coast of the northeastern US.
AVHRR Cloud Optical Depth Product
A comparison of 1-km resolution POES AVHRR Cloud Optical Depth products at 18:41 and 19:18 UTC (below) showed that the primary convergence band along the eastern side of a cyclonic circulation feature over Lake Superior exhibited significantly higher cloud optical depth values (blue to cyan color enhancement). This feature was responsible for later producing several inches of lake-effect snow along the Minnesota north shore of Lake Superior on 07 March 2011.
AVHRR Cloud Particle Effective Radius Product
Numerous ship condensation tracks could be seen in both the POES AVHRR visible image and the POES AVHRR Cloud Particle Effective Radius product (below) off the coast of California on 31 March 2011. The Cloud particle Effective Radius product indicated that the ship tracks were composed of slightly smaller particles (lighter cyan color enhancement) than the surrounding stratocumulus clouds that they were embedded within.
In addition to the CONUS region, a similar collection of POES AVHRR images and products are also created that cover the Alaska region (available under the “1km Resolution – Alaska” menu).