Large iceberg breaks off the Larsen-C ice shelf in Antarctica

July 12th, 2017 |

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

A comparison of Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images on 12 July 2017 (above; courtesy of William Straka, SSEC) shows the large iceberg (named A-68) that had separated from the Larsen-C ice shelf in Antarctica (Project MIDAS).

===== 13 July Update =====

A 12 July vs 13 July comparison of VIIRS Infrared Window and Day/Night Band images (below) revealed a slight expansion of the ice fracture, as Iceberg A-68 slowly drifted away from the Larsen-C ice shelf.

12 July vs 13 July Suomi NPP VIIRS Infrared Window (11.45 µm) images [click to enlarge]

12 July vs 13 July Suomi NPP VIIRS Infrared Window (11.45 µm) images [click to enlarge]

12 July vs 13 July Suomi NPP VIIRS Day/Night Band (0.7 µm) images [click to enlarge]

12 July vs 13 July Suomi NPP VIIRS Day/Night Band (0.7 µm) images [click to enlarge]

2016 Northern Hemisphere winter / Southern Hemisphere summer solstice

December 21st, 2016 |

Meteosat-10 Visible (0.635 µm) images [click to enlarge]

Meteosat-10 Visible (0.635 µm) images [click to enlarge]

The 2016 Northern Hemisphere winter / Southern Hemisphere summer solstice occurred at 1044 UTC on 21 December. EUMETSAT Meteosat-10 Visible (0.635 µm) images (above; source) showed the westward progression of the solar terminator (which separates daylight from darkness) at 3-hour intervals.

Nearly the entire continent of Antarctica was illuminated by 24 hours of daylight, as seen on JMA Himawari-8 Visible (0.64 µm) images (below; also available as a 60 Mbyte animated GIF). Full-disk images are routinely available at 10-minute intervals from Himawari-8 (and can be available as frequently as every 5 minutes from the GOES-R series).

Himawari-8 Visible (0.64 µm) images [click to play MP4 animation]

Himawari-8 Visible (0.64 µm) images [click to play MP4 animation]

With the continuous daylight, Antarctic surface air temperatures from AMRC Automated Weather Stations (below; source) were seen to warm above 40ºF along the coast, and above -30ºF in the interior.

AMRC AWS station surface temperatures at 20 December (22 UTC) and 21 December (05 and 11 UTC) [click to enlarge]

AMRC AWS station surface temperatures at 20 December (22 UTC) and 21 December (05 and 11 UTC) [click to enlarge]

Australian icebreaker runs aground in Antarctica

February 24th, 2016 |

Antarctic Infrared composite images [click to play animation]

Antarctic Infrared composite images [click to play animation]

The Australian icebreaker Aurora Australis was resupplying at Mawson Station along the Indian Ocean coast of Antarctica (map) when a strong storm (surface analysis) producing blizzard conditions — with winds as high as 86 knots gusting to 98 knots at 0936 UTC — caused it to break free from its mooring lines and run aground on 24 February 2016 (news release). Antarctic infrared composite images (using data from both geostationary and polar-orbiting satellites), above, showed the evolution and movement of the storm as it intensified close to Mawson Station early in the day on 24 February.

All-time record high temperature at the South Pole

December 25th, 2011 |
NOAA-18 AVHRR false color Red/Green/Blue (RGB) image

NOAA-18 AVHRR false color Red/Green/Blue (RGB) image

 

On 25 December 2011 a new all-time record high temperature of +9.9° F (-12.3° C) was set at the Amundsen-Scott South Pole Station — the previous all-time record high was +7.5° F (-13.6° C) on 27 December 1978. A NOAA-18 AVHRR false color Red/Green/Blue (RGB) image (above) displayed a variety of low cloud and high cloud features across the region at 11:17 UTC. Station identifier NZSP marks the location of the Amundsen-Scott station; the edge of the Ross Ice Shelf is at the top of the image.

A listing of available NZSP surface reports is shown below — the maximum temperature actually occurred at 02:50 UTC (15:50 local time). Note that there was also snow (S), light snow grains (SG-), or ice crystals (IC) being reported during much of the day that experienced the record high temperature!

NZSP surface reports

NZSP surface reports

 

NOAA-18 AVHRR 3.7 µm shortwave IR image

NOAA-18 AVHRR 3.7 µm shortwave IR image

A NOAA-18 AVHRR 3.7 µm shortwave IR image (above) depicted a number of patches of low altitude clouds composed of supercooled water droplets — these low cloud features appeared darker (warmer) since the shortwave IR channel is also sensitive  to the reflection of solar radiation off the cloud tops.

On the other hand, the corresponding NOAA-18 AVHRR 10.8 µm IR image (below) showed that there were high altitude cirrus clouds (cyan to dark blue color enhancement) in the vicinity of station NZSP. These high cirrus clouds could have been contributing to a “seeder-feeder effect” to help produce the periods of light precipitation that were observed on that day.

NOAA-18 AVHRR 10.8 µm IR image

NOAA-18 AVHRR 10.8 µm IR image

A EUMETSAT MetOp-A false color Red/Green/Blue (RGB) image (below; courtesy of Dave Santek, SSEC) showed the cloud features over the South Pole region at 02:52 UTC (very close to the time of the record high temperture).

MetOp-A false color Red/Green/Blue (RGB) image

MetOp-A false color Red/Green/Blue (RGB) image

 

For additional satellite images and information on this event, see the Antarctic Meteorological Research Center “On the Ice” blog and The Antarctic Sun.