Elevated NO2 signatures over the Northeast US

July 19th, 2019 |

TROPOMI NO2 concentration [click to enlarge]

TROPOMI NO2 concentration, courtesy of Bob Carp, SSEC [click to enlarge]

High temperatures (along with high dewpoints) prompted the issuance of Excessive Heat Warnings across much of the Northeast US on 19 July 2019. Under such conditions, surface NO2 concentrations in densely-populated urban areas often become elevated (primarily driven by emissions from motor vehicle exhaust, along with secondary sources such as coal-fired power plants and manufacturing / food processing industrial sources) — the high temperatures accelerate chemical reactions that form pollutants. The TROPOMI instrument detected plumes of elevated NO2 extending downwind (to the northeast) of major cities such as Philadelphia, New York City and Boston (above). The data are displayed using McIDAS-V.

A closer view centered on New York City is shown below.

TROPOMI NO2 concentration [click to enlarge]

TROPOMI NO2 concentration, courtesy of Bob Carp, SSEC [click to enlarge]

The Aqua MODIS Land Surface Temperature product around that time (below) revealed LST values in the 100-110ºF range across the New York City and Boston areas, where the daily maximum surface air temperatures were 95ºF and 93ªF, respectively.

Aqua MODIS Land Surface Temperature, with plots of daily maximum surface air temperatures [click to enlarge]

Aqua MODIS Land Surface Temperature, with plots of daily maximum surface air temperatures [click to enlarge]

Jet skier stranded by fog in Lake Superior

July 8th, 2019 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) images [click to play animation | MP4]

GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed narrow ribbons of fog over the northwestern portion of Lake Superior on 08 July 2019. A person attempting to navigate from Grand Portage, Minnesota — located northeast of Grand Marais Airport, identifier KCKC — to Isle Royale became lost in the fog and eventually ran out of fuel (media story).

Possibly compounding the fog-related visibility problem, GOES-16 Natural Color Red-Green-Blue (RGB) images (below) revealed that dense smoke from Canadian wildfires was lingering and also recirculating slowly northward across Lake Superior; this smoke occasionally reduced the surface visibility to 4 miles at Houghton, Michigan (identifier KCMX).

GOES-16 Natural Color RGB images [click to play animation | MP4]

GOES-16 Natural Color RGB images [click to play animation | MP4]

Canadian wildfire smoke across the Upper Midwest and Great Lakes

July 7th, 2019 |

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 (GOES-East) True Color Red-Green-Blue (RGB) images from the AOS site (above) showed the signature of dense smoke from Canadian wildfires that was being transported southward across parts of the Upper Midwest on 06 July 2019. While much of the smoke remained aloft, some of it was reaching the surface and restricting the visibility at locations such as International Falls, Baudette and Thief River Falls in northern Minnesota and Fargo in eastern North Dakota.

On the following day, the smoke settled farther southward over Wisconsin and Michigan (below). Much of the smoke again remained aloft, but continued to persist within the boundary layer at Baudette and International Falls — and it did briefly restrict the surface visibility at Green Bay in northeastern Wisconsin.

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 True Color RGB images [click to play animation | MP4]

===== 08 July Update =====

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 True Color RGB images [click to play animation | MP4]

On 08 July the smoke covered much of the Great Lakes and parts of adjacent states (above).

===== 09 July Update =====

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 True Color RGB images [click to play animation | MP4]

On 09 July, a gradual decreasing trend in the areal coverage and density of smoke over the Great Lakes was seen (above). A Suomi NPP VIIRS True Color RGB image acquired and processed by the CIMSS/SSEC Direct Broadcast ground station (below) showed that some of the smoke had moved over the Mid-Atlantic states and out across the adjacent offshore waters of the Atlantic Ocean.

Suomi NPP VIIRS True Color RGB image [click to enlarge]

Suomi NPP VIIRS True Color RGB image [click to enlarge]

Canadian wildfire smoke over the Upper Midwest

May 30th, 2019 |

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 (GOES-East) True Color Red-Green-Blue (RGB) images from the AOS site (above) revealed the arrival of a dense high-altitude smoke plume from the north, which cast a late-day shadow onto the top of a more aged layer of lower-altitude smoke over the Upper Midwest on 30 May 2019. These smoke layers were being transported from large wildfires that were burning across northern Alberta.

Images from the west-facing AOSS rooftop camera (below) showed the slow obscuration of the setting sun as the smoke layers aloft became increasingly thick.

Images from the west-facing AOSS rooftop camera [click to play animation | MP4]

Images from the west-facing AOSS rooftop camera [click to play animation | MP4]

The GOES-16 Smoke Detection product (below) flagged most of the lower-altitude smoke with its “High Confidence” category.

GOES-16

GOES-16 “Red” Visible (0.64 µm) and Smoke Detection product [click to play animation | MP4]

The higher-altitude smoke plume that moved southward contained some cirrus debris from the pyrocumulonimbus cloud that formed at the wildfire source in northern Alberta, so it was not classified as smoke by the Smoke Detection product — the plume itself did exhibit 10.3 µm infrared brightness temperatures as cold as -57ºC as it approached the Canada/US border (below).

GOES-16 "Clean" Infrared Window (10.3 µm) images [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.3 µm) images [click to play animation | MP4]

Some of the lower-altitude smoke exhibited GOES-16 Aerosol Optical Depth values as high as 1.0 to 2.0 (below).

GOES-16 Aerosol Optical Depth product [click to play animation | MP4]

GOES-16 Aerosol Optical Depth product [click to play animation | MP4]