What has the Large Iceberg (A68) been up to this year?

March 31st, 2020 |

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

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

A very large iceberg broke off the Larsen-C Ice Shelf on the Antarctic Peninsula in July 2017 (recall this CIMSS Satellite Blog post). While NOAA’s GOES-16 ABI visible sensors may not be ideal, they can monitor the iceberg’s location if the cloud cover is not too thick. The animation above shows the first 31 days of 2020, with just one image per day. More information from the National Ice Center.

H/T to @annamaria_84 for this tweet using Sentinel3 images:

Another outbreak of pyrocumulonimbus clouds in Australia

January 4th, 2020 |

Himawari-8

Himawari-8 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play animation | MP4]

Following a multi-day outbreak in late December 2019, Australian bushfires flared up again across far eastern Victoria and far southeastern New South Wales (along and ahead of a cold frontal passage) on 04 January 2020. A JMA Himawari-8 Target Sector was positioned over that region, providing images at 2.5-minute intervals — “Red” Visible (0.64 µm) images displayed the large smoke plumes with embedded pyro-convection, while Shortwave Infrared (3.9 µm) images revealed the widespread fire thermal anomalies or “hot spots” (clusters of red pixels).

Himawari-8 Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.4 µm) images (below) showed the development of 2 pyrocumulonimbus (pyroCb) clouds — the first over southern New South Wales west of Cooma (station identifier YCOM), and the second to the southwest of YCOM (near the border between Victoria and New South Wales). The second pyroCb eventually exhibited cloud-top infrared brightness temperature (IRBT) values of -70ºC and colder (purple pixels). To be classified as a pyroCb, a deep convective cloud must be generated by a large/hot fire, and eventually exhibit cloud-top 10.4 µm IRBTs of -40ºC and colder (thus assuring the heterogeneous nucleation of all supercooled water droplets to ice crystals within the thunderstorm anvil).

Himawari-8 Shortwave Infrared (3.9 µm, top) and "Clean" Infrared Window (10.4 µm, bottom) images [click to play animation | MP4]

Himawari-8 Shortwave Infrared (3.9 µm, top) and “Clean” Infrared Window (10.4 µm, bottom) images [click to play animation | MP4]

An aircraft flying very near or through one of these pyroCb clouds experienced severe turbulence:



Farther to the north, another pyroCb developed near Nowra, New South Wales (YSNW) — which briefly exhibited a -40ºC cloud-top IRBT at 0319 UTC, but then re-intensified around 08 UTC (below).

Himawari-8 Shortwave Infrared (3.9 µm, top) and "Clean" Infrared Window (10.4 µm, bottom) images [click to play animation | MP4]

Himawari-8 Shortwave Infrared (3.9 µm, top) and “Clean” Infrared Window (10.4 µm, bottom) images [click to play animation | MP4]

In a sequence of VIIRS True Color Red-Green-Blue (RGB) and Infrared Window (11.45 um) images from NOAA-20 and Suomi NPP as viewed using RealEarth (below), the Nowra pyroCb was less ambiguous during the 03-04 UTC time period — and the aforementioned pair of pyroCbs straddling the border between Victoria and New South Wales were also evident.

Sequence of VIIRS True Color RGB and Infrared Window (11.45 um) images from NOAA-20 and Suomi NPP [click to enlarge]

Sequence of VIIRS True Color RGB and Infrared Window (11.45 um) images from NOAA-20 and Suomi NPP [click to enlarge]

===== 06 January Update =====

GOES-16 Natural Color RGB images + Smoke Detection derived product [click to play animation | MP4]

GOES-16 Natural Color RGB images + Smoke Detection derived product [click to play animation | MP4]

On 06 January, GOES-16 (GOES-East) Natural Color RGB images (above) displayed the hazy signature of high-altitude smoke (originating from previous episodes of Australian fires) over parts of Chile and Argentina — and the corresponding GOES-16 Smoke Detection derived product flagged much of this feature as “High Confidence” smoke (red).

In addition, GOES-17 (GOES-West) True Color RGB images created using Geo2Grid (below) showed a dense pall of smoke over the South Pacific Ocean (northeast of New Zealand). This was smoke from the 04 January outbreak of fires.

GOES-17 True Color RGB images [click to play animation | MP4]

GOES-17 True Color RGB images [click to play animation | MP4]

===== 08 January Update =====

GOES-17 True Color RGB images, 05-08 January [click to play animation | MP4]

GOES-17 True Color RGB images, 05-08 January [click to play animation | MP4]

Full Disk GOES-17 True Color RGB images from the AOS site (above) showed the slow eastward transport of a dense pall of smoke (hazy shades of tan to light brown) across the South Pacific Ocean during the 05-08 January period.

Late in the day, GOES-17 True Color images also showed a small area of smoke drifting southward across the coast of Antarctica (below).

GOES-17 True Color images [click to play animation | MP4]

GOES-17 True Color images [click to play animation | MP4]

This was confirmed by the OMPS Aerosol Index product (below), which displayed a small lobe becoming detached from one of the larger smoke features crossing the South Pacific Ocean.

Suomi NPP OMPS Aerosol Index composites, 04-08 January (credit: Colin Seftor, SSAI)

Suomi NPP OMPS Aerosol Index composites, 04-08 January (credit: Colin Seftor, SSAI)

 

Solstice images of Antarctica and Alaska

December 21st, 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 that most of Antarctica experienced 24 hours of full solar illumination during the Southern Hemisphere’s Summer Solstice on 21 December 2019. Through breaks in the cloud cover, a few bright areas of sun glint were also evident, moving from west to east, due to the reflection of sunlight off ice-free water.

In spite of receiving 24 hours of sunlight, interior areas of the continent remained quite cold — due to high elevation and deep snow cover. For example, surface air temperatures at station 8927 near the center of Antarctica remained within the -25 to -35ºF range on 21 December (source).

Surface air temperatures (ºF) at automated weather stations across Antarctica [click to enlarge]

Surface air temperatures (ºF) at automatic weather stations across Antarctica [click to enlarge]

In the Northern Hemisphere, GOES-17 (GOES-West) Visible images (below) revealed a few hours of illumination of the southern summits of Denali and nearby portions of the Alaska Range. Note the presence of much colder surface air temperatures (-20s and -30s F) north of the Alaska Range.

GOES-17 "Red" Visible (0.64 µm) images [click to play animation | MP4]

GOES-17 “Red” Visible (0.64 µm) images [click to play animation | MP4]

Farther to the north across Interior Alaska, some locations reported minimum air temperatures in the -40s to -50s F. A Suomi NPP VIIRS Infrared image (below) showed surface brightness temperatures as cold as -50ºC or -58ºF (brighter yellow enhancement) in the Yukon Flats area around Fort Yukon (PFYU).

NOAA-20 VIIRS Infrared Window (11.45 µm) image at 2220 UTC [click to enlarge]

Suomi NPP VIIRS Infrared Window (11.45 µm) image at 2220 UTC [click to enlarge]

Strong cyclone near Antarctica

March 26th, 2019 |

Composites of geostationary and polar orbiter Infrared imagery [click to play animation]

Composites of geostationary and polar orbiter Infrared imagery [click to play animation]

Composites of Infrared imagery (above) and Water Vapor imagery (below) from the AMRC site showed an anomalously strong (MSLP | 925 hPa winds | source) cyclone that was moving southeastward across the South Pacific Ocean toward the coast of Antarctica on 26 March 2019. These composites blend images from both geostationary and polar orbiting satellites; the storm is located in the upper right quadrant of the images. On the Infrared imagery, brighter white shades over much of the middle of Antarctica indicated a very cold surface — in fact, surface air temperatures were as cold as -84ºF over the interior of the continent at 23 UTC.

Composites of geostationary and polar orbiter Water Vapor imagery [click to play animation]

Composites of geostationary and polar orbiter Water Vapor imagery [click to play animation]

The storm was evident along the southern limb of GOES-16 Full Disk scans, as seen on Mid-level Water Vapor (6.9 µm) and “Red” Visible (0.64 µm) images (below). The location of AMRC AWS station 8930 (Thurston Island) near the coast of Ellsworth Land in West Antarctica is indicated in red.

GOES-16 Mid-level Water Vapor images [click to play animation | MP4]

GOES-16 Mid-level Water Vapor (6.9 µm) images [click to play animation | MP4]

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

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

This storm was also evident at the bottom center of a GOES-17 + GOES-16 composite of north-to-south True Color Red-Green-Blue (RGB) swaths of 15-minute illumination at local solar noon — beginning at 12 UTC in the east, and ending at 03 UTC in the west — combined and displayed in a Mollweide projection (below; courtesy of Rick Kohrs, SSEC).

GOES-17 + GOES-16 True Color RGB image [click to enlarge]

GOES-17 + GOES-16 True Color RGB image [click to enlarge]

A time series of surface observation data from AWS station 8930 on Thurston Island (below) showed that southeasterly winds peaked at 113 knots (58 m/s) late in the day on 26 March as the strong low pressure system approached. According to AMRC staff, this particular AWS is located on a nunatak near Parker Peak in the Walker Mountains (map) — such an exposure is prone to periods of strong winds, requiring a recent retrofitting of special instrumentation designed to withstand and measure higher wind speeds.

Tiime series of surface observation data from AWS station 8930 Thurston Island [click to enlarge]

Time series of surface observation data from AWS station 8930 Thurston Island [click to enlarge]

A closer look with GOES-16 Visible and Low-level Water Vapor (7.3 µm) images (below) revealed small wave perturbations in the cloud field and the eventual formation of a banner cloud as Peter I Island was acting as an obstacle to the strong boundary layer winds south of the storm center.

GOES-16 "Red" Visible (0.64 µm. left) and Low-level Water Vapor (7.3 µm, right) images [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm. left) and Low-level Water Vapor (7.3 µm, right) images [click to play animation | MP4]

A timely overpass of the Landsat-8 satellite provided a 30-meter resolution Landsat-8 False Color RGB image, viewed using RealEarth (below), of these orographically-induced cloud perturbations.

Landsat-8 False Color image [click to enlarge]

Landsat-8 False Color RGB image [click to enlarge]

The orographic wave clouds downwind of Peter I Island could also be seen on 375-meter resolution Suomi NPP VIIRS True Color RGB and Infrared Window (11.45 µm) images at 19 UTC and 21 UTC (below).

Suomi NPP VIIRS True Color RGB and Infrared Window (11.45 µm) images 1t 19 UTC and 21 UTC [click to enlarge]

Suomi NPP VIIRS True Color RGB and Infrared Window (11.45 µm) images at 19 UTC and 21 UTC [click to enlarge]