Suomi NPP VIIRS 0.7 µm Day/Night Band and 11.45 µm IR channel images

A cyclone rapidly intensified (deepening 42 mb in 24 hours, and 26 mb in 12 hours) in the Gulf of Alaska on 26 September 2012, and was expected to produce winds up to hurricane force. An AWIPS image comparison of Suomi NPP VIIRS 0.7 µm Day/Night Band and 11.45 µm IR channel images at 11:24 UTC (above) showed great detail to the cloud features as the storm began to exhibit a classic “cusp” signature as rapid intensification was underway (IR image with surface analysis overlay).

McIDAS images of GOES-15 6.5 µm water vapor channel data (below; click image to play animation) portrayed the evolution of the storm from 04:00 UTC to 23:45 UTC.

GOES-15 6.5 µm water vapor channel images (click to play animation)

View only this post Read Less

Suomi NPP VIIRS 0.7 µm Day/Night Band, 11.45 µm IR, and IR difference “fog/stratus product” images

A comparison of AWIPS images of Suomi NPP VIIRS 0.7 µm Day/Night Band, 11.45 µm IR, and IR difference “fog/stratus product” data (above) revealed that the Day/Night Band (DNB) can be used for nocturnal detection of dense layers of wildfire smoke aloft (in this case, over parts of Montana, Wyoming, North Dakota, South Dakota, and Nebraska). The brighter DNB signal of the elevated smoke layer was not correlated with any features seen on either the IR image or the fog/stratus product image at 08:04 UTC (2:04 AM  local time) on 26 September 2012.

The MODIS aerosol optical depth (AOD) product (below) showed that high ADO values were found over that region during the afternoon hours (20 UTC) on 25 September. Forward trajectories from the IDEA-I site indicated that the majority of this smoke would be drifting slowly eastward.

MODIS aerosol optical depth (AOD) product

The hazy signal of this veil of smoke aloft could also be seen on GOES-14 0.63 µm visible channel images late in the day on 25 September and again early in the day on 26 September (below), when the sun angle was low to help highlight the presence of the smoke.

GOES-14 0.63 µm visible channel images

View only this post Read Less

Suomi NPP VIIRS 0.7 µm Day/Night Band image + 11.45 µm IR channel image

AWIPS images of Suomi NPP VIIRS 0.7 µm Day/Night Band and 11.45 µm IR channel data (above) showed a thunderstorm complex that stretched from northern Missouri to southern Illinois at 08:23 UTC (3:23 AM local time) on 25 September 2012. The IR image revealed a number of cold overshooting tops (exhibiting IR brightness temperatures as cold as -79 C), while the Day/Night Band image showed several bright “streaks” which were signatures of lightning illuminating the cloud tops as the VIIRS instrument was scanning the feature. Note how many city lights were able to be seen through the veil of thin cirrus around the edges of the thunderstorms.

The SSEC Web Map Server offered a larger scale view (below), also combining the Suomi NPP VIIRS Day/Night Band and IR images with the legacy IR difference “fog/stratus product”.

Suomi NPP 0.7 µm Day/Night Band + 11.45 µm IR channel + IR difference “fog/stratus product”

View only this post Read Less

GOES, POES AVHRR, MODIS, and Suomi NPP VIIRS IR images (click to play animation)

The GOES-13 (GOES-East) satellite suffered anomalies that forced it to be placed into standby mode late in the day (at 21:22 UTC) on 23 September 2012 (NOAA NESDIS notification message). The GOES-15 (GOES-West) satellite was then placed into Full Disk scan mode, supplying images to cover as much of the eastern US and adjacent offshore waters as possible at 30-minute intervals.

During the GOES-13 outage, satellite imagery viewed in AWIPS on the “CONUS” scale did not display the complete full disk scan information from GOES-15, resulting in large areas with no data over the southeastern and eastern US (note: the full GOES-15 scan sector is available when viewed on the AWIPS “North America” scale, but the data resolution is degraded due to the very large satellite viewing angle). However, during this period there were a handful of overpasses from a number of polar-orbiting satellites, allowing imagery from the POES AVHRR, MODIS, and Suomi NPP VIIRS instruments to help fill in some of the gaps on the GOES imagery. Examples of these polar-orbiting IR images interjected among the available GOES-15 IR images are shown above. During the 21-hour GOES-East outage period, there were a total of 25 polar-orbiting passes (15 POES AVHRR, 7 MODIS, and 3 Suomi NPP VIIRS) available to offer high spatial resolution data over areas with poor quality GOES-15 data coverage.

CIMSS is able to provide POES AVHRR, MODIS, and Suomi NPP VIIRS imagery in AWIPS format to NWS forecast offices (via Unidata LDM subscription) to serve as an additional source of satellite imagery that could prove to be useful during such geostationary satellite outages.

While the GOES-13 outage persists, real-time GOES-14 imagery can be viewed using the SSEC Geostationary Image Browser.

UPDATE: As of 17:45 UTC on 24 September, GOES-14 replaced GOES-13 as the operational GOES-East satellite (NOAA/NESDIS notification message). After the 18:31 UTC image (below), there was complete coverage of the CONUS from GOES-14 (as viewed using all AWIPS scales).

GOES-14 10.7 µm IR image

In the early morning, before GOES-14 took over as the operational GOES-East satellite, it captured a beautiful sequence of 0.63 µm visible channel images (below; click image to play animation) showing river valley fog across parts of Kentucky, West Virginia, and adjacent states. Also evident early in the animation across the far southern portion of the images is the hazy signature of smoke aloft, transported from the large fires that have been burning in the Pacific Northwest states.

GOES-14 0.63 µm visible channel images (click image to play animation)

View only this post Read Less