MODIS and AVHRR Lake Surface Temperatures (click image to play animation)

Clear skies over the upper Midwest on the morning of 13 June 2012 allowed the MODIS instrument on board Aqua and the AVHRR instrument on board NOAA-19 to sense the surface temperature of Lakes Michigan and Superior. Which instrument yielded observations that were closer to those recorded in situ by the moored buoys maintained by the National Data Buoy Center? The loop above of MODIS Lake Surface Temperatures and AVHRR Lake Surface Temperatures suggests that the MODIS-derived values are 1-3 Fahrenheit degrees warmer. MODIS values are also closer to the observed values at the moored buoys (45002 and 45007 in Lake Michigan, 45003 in Lake Huron and 45004 in Lake Superior). The higher spectral resolution on MODIS leads to a more accurate depiction of the lake surface in this case.

The National Weather Service in Sullivan, WI, has noted that lake temperatures are running much warmer than normal this year, in part because of the record warmth in March.

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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) revealed the development of a very broad and dense smoke plume emanating from a large wildfire that was burning just northwest of Goose Bay, Labrador (station identifier CYYR)  in far eastern Canada on 13 June 2012. Note the appearance of a number of bright “pyro-cumulus” clouds near the fire source region, as the very hot fires produced intense updrafts to form large towering cumulus clouds. As an aside, it is interesting to note that there were still a number of large ice floes (slow-moving brighter white features) not far off the Labrador coast, which were drifting slowly northward during the day.

McIDAS images of 375-meter resolution (projected onto a 1-km AWIPS grid) Suomi NPP VIIRS 0.64 µm visible channel data and 3.74 µm shortwave IR channel data (below) showed the large size of the fire “hot spot” (yellow to red to black pixels), in addition to the thick smoke plume.

Suomi NPP VIIRS 0.64 µm visible channel and 3.74 µm shortwave IR channel images

A comparison of Suomi NPP VIIRS 3.74 µm shortwave IR images from 12 June and 13 June (below) show how large the fire hot spot had grown in a day. Note that the surface air temperature at Goose Bay plotted on the 12 June image was 93 F (33.9 C) — the high temperature at Goose Bay on that day was actually 95 F (35 C), only 2.2 F (1.2 C) shy of their all-time record high temperature for the month of June.

Suomi NPP VIIRS 3.74 µm shortwave IR images (12 June and 13 June)

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Suomi NPP VIIRS 0.64 µm visible channel images

Parts of far northeastern Manitoba, Canada received significant snowfall on 11 June 2011, with 20 cm (7.9 inches) falling at Gillam (station identifier CYGX). On the following day (12 June 2012), Suomi NPP VIIRS 0.64 µm visible channel images (above) revealed that the remaining snow cover could be seen through the patches of clouds that were moving over that region.

A comparison of the 17:37 UTC (12:37 PM local time) Suomi NPP VIIRS 0.64 µm visible channel image with the corresponding 1.61 µm near-IR “snow/ice channel” image (below) confirmed that the brighter patch seen on the ground in the visible image was indeed snow cover (which shows up as a much darker shade of gray than the surrounding bare ground areas).

Suomi NPP VIIRS 0.64 µm visible image + 1.61 µm near-IR image

Farther to the south, a MODIS Land Surface Temperature (LST) product image at 09:06 UTC (4:06 AM local time) on 12 June (below) showed widespread areas from far southern Manitoba into parts of North Dakota, South Dakota, and Minnesota that exhibited LST values at or just below freezing (32º F or 0º C, darker blue color enhancement). The coldest overnight lows that morning were 32º F at Langdon, North Dakota and Warroad, Minnesota.

MODIS Land Surface Temperature product

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MODIS true color and false color RGB images from 08/09/10/11 June

The High Park Fire was started by lightning early in the morning on 09 June 2012, approximately 15 miles west of Fort Collins (InciWeb). Daily comparisons of 250-meter resolution MODIS true color and false color Red/Green/Blue (RGB) images from the SSEC MODIS Today site (above) are shown for 08 June (the day before the fire started; note the burn scar on the false color image from the Hewlett Fire that burned near that same location back in May 2012), and then after the fire was burning on 09 June, 10 June, and 11 June 2012. The areal extent of the smoke is clearly seen on the true color images, while the false color images show very hot active fires (bright pink on the 09 and 10 June images) or the coverage of the burn scar (the light brown feature seen through the thin veil of smoke on the 11 June image).

AWIPS images of 1-km resolution MODIS 3.7 µm shortwave IR data (below) showed the growth of the fire “hot spot” from 19:42 UTC on 09 June to 09:18 UTC on 10 June. Note how the fire hot spot was seen to grow eastward and then curve southward in the wake of a cold frontal passage that brought strong northerly winds to the region.

MODIS 3.7 µm shortwave IR images from 09/10 June

The curved shape of the fire hot spot was more clearly seen on a 375-meter resolution (projected onto a 1-km AWIPS grid) Suomi NPP VIIRS 3.74 µm shortwave IR image at 08:30 UTC or 2″30 AM local time on 10 June (below). The corresponding 0.7 µm VIIRS Day/Night Band image showed the bright glow of the actively burning fire complex, which was likely accentuated with moonlight reflection off the top of the dense smoke plumes that were rising over the fire source region.

Suomi NPP VIIRS 3.74 µm shortwave IR + 0.7 µm Day/Night Band image

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