Suomi NPP VIIRS true-color Red/Green/Blue (RGB) image

After the Suomi NPP satellite had experienced an anomaly and gone into a sun-pointing “safe mode” on 24 March, all the satellite instruments began to successfully recover by 26 March 2012. Shown above is a 750-meter resolution true-color Red/Green/Blue (RGB) image from the VIIRS instrument, acquired via the Direct Broadcast ground station at the Space Science and Engineering Center at the University of Wisconsin – Madison (image courtesy of Liam Gumley, SSEC). A number of interesting features can be seen in the image, including (1) the break-up of ice in Hudson Bay and James Bay in Canada, (2) smoke plumes from fires burning across parts of the southeastern US, and (3) the outflow of sediment-rich water from the mouth of the Mississippi River (and other rivers) into the Gulf of Mexico.

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GOES-13 + GOES-15 6.5 µm water vapor channel images (with surface analyses and buoy reports)

GOES-15 was restored to operational status mid-day on 23 March 2012 (after a satellite outage that began after 20:30 UTC on 21 March). Using AWIPS, a sequence of  GOES-13 6.5 µm water vapor channel images early in the day, followed by the return of GOES-15 6.5 µm water vapor channel images (above) showed the dramatic improvement in the appearance of features associated with a large mid-latitude cyclone over the East Pacific Ocean. This cyclone was producing Storm Force winds over the open waters of the Pacific, as well as Gale Force winds off the coasts of California and Oregon.

McIDAS images of GOES-15 0.63 µm visible channel data (below) portrayed the large size of this storm system.

GOES-15 0.63 µm visible channel images (click image to play animation)

Shown below is an HD-format version of an animation of GOES-15 0.63 µm visible channel images (courtesy of Tim Schmit, NOAA/ASPB/CIMSS).

GOES-15 0.63 µm visible channel imsage (click image to play animation)

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MODIS 6.7 µm water vapor image + GOES-13 6.5 µm water vapor imageÂ

After 20:30 UTC on 21 March 2012, GOES-15 (GOES West) experienced a bad momentum unload, and at this point the satellite went into  a sun acquisition mode (a “safe mode”) and stopped transmitting data (latest GOES-15 status messages). NOAA/NESDIS immediately began to operate GOES-13 (GOES East) in continuous Full Disk scan mode, in order to provide imagery as far west as possible every 30 minutes. However, due to the extreme viewing angle from GOES-13 (positioned over the Equator at 75 degrees West longitude), the image quality over the western US was degraded (since the effective pixel resolution was so large). In addition, Alaska, Hawaii, and the Pacific Region were effectively without useful GOES imagery (although some of these areas could make use of Japanese MTSAT imagery to help fill the GOES-15 imagery gap).

Shortly after the GOES-15 outage, AWIPS comparisons of a 1-km resolution MODIS 6.7 µm water vapor image with the corresponding GOES-13 6.5 µm water vapor image (above) as well as the MODIS 11.0 µm IR channel image and the corresponding GOES-13 10.7 µm IR image (below) demonstrate the value of using higher spatial resolution polar-orbiter (from the Terra and Aqua satellites) MODIS imagery to supplement the degraded geostationary GOES-13 imagery during the GOES-15 outage. In these 2 examples, the GOES-13 viewing angle for San Francisco, California is 65 degrees, making the effective resolution of the “4 km” IR and water vapor image pixels closer to 16 km. In addition, the large satellite viewing angles were creating a significant “parallax error“, shifting the apparent location of high cloud features to the northwest.

MODIS 11.0 µm IR image + GOES-13 10.7 µm IR image

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MODIS 6.7 µm water vapor image + GOES-13 6.5 µm water vapor image

On the following day,  AWIPS comparisons of a MODIS 6.7 µm water vapor image with the corresponding GOES-13 6.5 µm water vapor channel image (above) as well as a MODIS 11.0 µm IR channel image with the corresponding GOES-13 10.7 µm IR channel image (below) showed a storm moving into the far southern panhandle of Alaska. In the case, the GOES-13 satellite viewing angles for Seattle, Washington and Juneau, Alaska were 71 degrees and 82 degrees, respectively.

MODIS 11.0 µm IR image + GOES-13 10.7 µm IR image

Similarly, an AWIPS comparison of a 1-km resolution POES AVHRR 12.0 µm IR image with the corresponding GOES-13 10.7 µm IR image (below) shows another source for polar-orbiter satellite imagery to supplement GOES in this type of situation.

POES AVHRR 12.0 µm IR image + GOES-13 10.7 µm IR image

CIMSS participation in GOES-R Proving Ground activities includes making a variety of POES AVHRR and  MODIS images and products available for National Weather Service forecast offices to add to their local AWIPS workstations. Currently there are 57 NWS offices receiving MODIS imagery and products from CIMSS.

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MODIS Sea Surface Temperature product

On 20 March 2012, the Milwaukee/Sullivan NWS forecast office posted a story about possible record warm water temperatures in southern Lake Michigan. Then, on 21 March 2012, the Lake Erie water temperature measured at Buffalo, New York was 39º F, which tied for the warmest water temperature ever measured there during the month of March (Lake Erie water temperature records).

An AWIPS image of the MODIS Sea Surface Temperature (SST) product (above) showed that there were a number of pockets of warm SST values in the 50s F (green to yellow color enhancement) within Lakes Michigan, Huron, Erie, and Ontario, with only a few isolated SST values in the 30s F (darker blue color enhancement) in each of those lakes.

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