Thick smoke over the Upper Midwest region

September 17th, 2012 |
GOES-13 0.63 µm visible channel images (click image to play animation)

GOES-13 0.63 µm visible channel images (click image to play animation)

McIDAS images of GOES-13 0.63 µm visible channel data (above; click image to play animation) showed an unusually thick veil of smoke  moving eastward across much of the Upper Midwest region of the US on 16 September 2012.

This thick layer of airborne smoke contributed to a colorful sunset, as seen by the west-facing camera on top of the SSEC / AOS building at the University of Wisconsin – Madison (below; click image to play animation). Note the appearance of a number of very short aircraft contrails: an indication that the air aloft at flight altitude was very dry.

West-facing SSEC/AOS rooftop camera images (click image to play animation)

West-facing SSEC/AOS rooftop camera images (click image to play animation)

SSEC lidar aerosol backscatter and particulate circular depolarization ratio data (below) indicated that the smoke layer occupied a very deep portion of the middle troposphere (primarily between 2 km and 8 km in altitude) by the end of the day.

Lidar aerosol backscatter and particualte circular depolarization ratio

Lidar aerosol backscatter and particualte circular depolarization ratio

Backward air parcel trajectories using the NOAA ARL HYSPLIT model (below) suggested a long-range transport of smoke from the extensive wildfires which had been burning in Idaho and adjacent states during the previous days.

NOAA ARL HYSPLIT backward air parcel trajectories

NOAA ARL HYSPLIT backward air parcel trajectories

Pyrocumulus clouds associated with wildfires in Wyoming

September 15th, 2012 |
GOES-15 (left) and GOES-13 (right) 0.63 µm visible images (click image to play animation)

GOES-15 (left) and GOES-13 (right) 0.63 µm visible images (click image to play animation)

McIDAS images of GOES-15 (GOES-West) and GOES-13 (GOES-East) 0.63 µm visible channel data (above; click image to play animation) revealed smoke plumes and pyrocumulus clouds associated with a pair of large wildfires that were burning in western Wyoming on 15 September 2012. Because of difference in viewing angle between the two satellites, the pyrocumulus clouds appeared brighter white on the GOES-15 images (due to more direct reflection of sunlight off the western edges of the clouds), while on the GOES-13 images the “overshooting” clouds cast more well-defined shadows on top of the smoke layer below.

A comparison of AWIPS images of Suomi NPP VIIRS 0.64 µm visible channel and 11.45 µm IR channel data at 19:36 UTC or 1:36 PM local time (below) showed that the southernmost fire burning along the eastern slopes of the Wind River Range had already developed a pronounced pyrocumulus cloud, which exhibited an IR brightness temperature as cold as -40º C (green color enhancement).

Suomi NPP VIIRS 0.64 µm visible channel and 11.45 µm IR channel images

Suomi NPP VIIRS 0.64 µm visible channel and 11.45 µm IR channel images

According to 12 UTC rawinsonde data from nearby Riverton, Wyoming (station identifier KRIW), the -40 C IR cloud top brightness temperature roughly corresponded to an altitude just over 31,000 feet or 9.6 km (below).

Riverton, Wyoming rawinsonde data at 12 UTC

Riverton, Wyoming rawinsonde data at 12 UTC

GOES-14 Full Disk images at 30-minute intervals

September 14th, 2012 |
GOES-14 6.5 µm water vapor channel images (click image to play animation)

GOES-14 6.5 µm water vapor channel images (click image to play animation)

As a part of the GOES-14 Super Rapid Scan Operations for GOES-R (SRSOR) testing, the satellite provided full-disk images at 30-minute intervals during the day on 14 September 2012. For current GOES satellites, the operational full-disk image interval is 3 hours; the ABI instrument on GOES-R will provide a full-disk image every 5 minutes. GOES-14 0.65 µm water vapor channel images are shown above (click image to play animation).

The corresponding GOES-14 0.63 µm visible channel images (below; click image to play animation) revealed two features of interest over the eastern portion of the full disk which were more obvious due to the large forward scattering geometry: (1) a large pall of smoke over the Amazon basin and much of interior South America, a result of widespread biomass burning (magnified view), and (2) Saharan Air Layer dust located to the north, east, and southeast of Tropical Storm Nadine in the North Atlantic Ocean (magnified view).

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

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

Super Typhoon Sanba

September 13th, 2012 |
MTSAT-2 10.8 µm IR channel images (click image to play animation)

MTSAT-2 10.8 µm IR channel images (click image to play animation)

McIDAS images of MTSAT-2 10.8 µm IR channel images (above; click image to play animation) showed the formation of a large and well-defined eye as Super Typhoon 17W (Sanba) intensified over the West Pacific Ocean on 13 September 2012.

A plot of the CIMSS Advanced Dvorak Technique intensity estimate (below) showed the trend of rapid intensification.

CIMSS ADT plot for Storm 17W (Sanba)

CIMSS ADT plot for Storm 17W (Sanba)

Sanba was in an environment characterized by relatively low values of Deep Layer Wind Shear (below), which favored intensification.

MTSAT-2 IR images + Deep layer wind shear

MTSAT-2 IR images + Deep layer wind shear

Sanba had also been moving over a region with very warm Sea Surface Temperatures and a very high Ocean Heat Content values (below).

Track of Sanba overlaid on Sea Surface Temperature + Ocean Heat Content products

Track of Sanba overlaid on Sea Surface Temperature + Ocean Heat Content products

The first daylight MTSAT-2 0.7 µm visible channel images (below) showed nice eye and eyewall structure.

MTSAT-2 0.7 µm visible channel images

MTSAT-2 0.7 µm visible channel images