The Prince Gustav Channel was covered by an ice shelf which collapsed in the 1990’s, and for many years it was possible to sail a ship around James Ross Island.
Recently it has been covered with sea ice frozen to the land – we call this fast ice, and it’s usually only a few metres thick of frozen sea water – rather than hundreds of metres thick snow derived ice shelf.
Recent images from the TERRA satellite show that this fast sea ice is finally breaking out.
It’ll soon be possible to circumnavigate James Ross Island once more.
The Prince Gustav Channel early spring Antarctic summer 2016/7 from MODIS satellite imagery on the TERRA satellite.
This map shows the location of the channel.
The Antarctic Peninsula showing the location of the Prince Gustav Channel.
Now it has started I wonder how long it will take to finally clear. Or more fun, I wonder if tour ships will be able to get around the island?
I love looking at satellite images of the Antarctic and picking out the icebergs. In the last few years we have had great stories about the giant icebergs A68 in 2020, A76 in 2022 and most recently A23a currently in the Southern Scotia Sea.
At the moment there are two of very large icebergs at the southern end of Antarctic Sound. Here is a map to orientate yourself and show where they are.
A basemap with a MODIS image from 7 October 2024. The yellow box is the location of Antarctic Sound and is expanded on below.
There is a lot in the image above. As well as the Antarctic Peninsula there are clouds, sea ice, and icebergs. Zooming into Antarctic Sound shows the giant icebergs more clearly.
A MODIS satellite image of Antarctic Sound taken on 7 October 2024. Two large icebergs are at the southern end of the Sound. These are A80A and A76C.
And in the radar sensor on Sentinel-1 the icebergs leap out because that sensor “sees” through the clouds.
A Sentinel-1 SAR image from 8 October 2024. Land is coloured blue, the giant icebergs are solid grey, and sea ice and smaller icebergs make up the grey shades colouring the rest of the image.
A80A is 10×9 nautical miles and it calved from the Larsen D Ice Shelf in November 2022. A76C is currently 16×7 nautical miles and was part of iceberg A76 that calved from the Ronne Ice Shelf in May 2021. These are pretty decent sized icebergs: A80A looks to be pinned against Rosamel Island and Andersson Island at the southern end of Antarctic Sound, and A76C grounded against A80A.
Personally I would be surprised if they broke out before the start of the Antarctic season proper, so they could cause some complexities in navigating into the Weddell Sea through Antarctic Sound.
Finally we can’t forget the current monster of them all: A23A at 40×32 nautical miles, and it has been spinning above Pirie Bank north of the South Orkney’s since April 2024. I described it as “the iceberg that just refuses to die” when I spoke to the BBC, and it has been spinning for seven months in pretty much the same location. When it finally breaks free, it’ll head up towards South Georgia and it’s inevitable demise rapid demise.
A MODIS satellite image from 13 October 2024 showing iceberg A23A just north of the South Orkney Islands.
It’s amazing to think that A23A has been in existence since 1986 when it fractured from the Filchner-Ronne Ice Shelf.
The summary? It looks like if you’re going South this season you could see some very big icebergs, and navigation could be complicated in the North West Weddell Sea.
Posted in Science, Uncategorized. Tags: Antarctic Peninsula, Antarctic Sound, antarctica, iceberg, Icebergs on October 15, 2024 by Mark Brandon. Mark Brandon • August 31, 2018
Just over a year ago in July 2017 iceberg A68 calved from the Larsen C Ice Shelf. I appeared on BBC News before it actually calved explaining what was happening.
At first A68 was slow to move and as I predicted back then, it likely got stuck on the sea bed (we say “grounded”). It has stayed pretty much in the same place through to July 2018.
But now A68 has started to swing northwards.
As the light is coming back to Antarctica, at high latitudes visual imagery is very washed out. But if we look at other data such as the brightness temperature, you can see some striking features.
This image is from 20 August 2018.
Corrected Reflectance (True Color) from the Suomi NPP Visible Infrared Imaging Radiometer Suite (VIIRS), and the Brightness Temperature (Band I5, Day). Image from 20 August 2018.
With the brightness temperature data set, brighter colours indicate higher temperatures. The Larsen Ice shelf and A68a are glacial ice and so cold, they appear dark purple. The sea ice is thinner and warmer and in contact with the ocean so the purple shade is lighter. The leads which are cracks in the sea ice and so open water and / or very thin sea ice appear as relatively bright lines. On the bottom right of that image you can see that under certain circumstances the brightness temperature data set can see through clouds.
…continue reading →
Posted in Science. Tags: A68, antarctica, satellite, sea ice on August 31, 2018 by Mark Brandon. Mark Brandon • February 13, 2018
Iceberg A68 calved from the Larsen C ice shelf earlier this year. I wrote about before.
As the berg calved it is starting to reveal a patch of seafloor that has been covered by thick glacial ice, and as the BAS press release says this has revealed:
a mysterious marine ecosystem that’s been hidden beneath an Antarctic ice shelf for up to 120,000 years.
To have the chance of making observations in an untouched environment like that is so exciting, that the British Antarctic Survey are running an expedition to investigate. You can read about it in a great piece by Victoria Gill on the BBC news site, and the brilliant Katrin Linse has done some great work with Radio 4 and the BBC Breakfast program (2hrs 20 mins in source BAS twitter account) explaining both the purpose and the work.
I was looking this morning at the recent Sentinel-1 imagery on Polarview, this is an image of A68 captured on 11 February 2018. It’s big – about 5,200 km2.
Iceberg A68 and the Larsen C Ice shelf captured from with the Sentinel-1 SAR sensor 11 February 2018.
I labelled some features in the image: the iceberg and the ice shelf are the relatively solid grey colour. The blue overlay is where land and the ice shelf roughly were (it’s called a land mask).
One thing you can see is the speckled grey colour which covers the top right hand side.
This speckled grey is sea ice.
It’s a relatively thin cover of a typically 1-3 m thick.
Antarctic Sea ice.
If you map the current sea ice distribution, and the location of iceberg A68 you can see how much sea ice they are going to have to sail through to reach the region.
Larsen C, the iceberg A68 and the sea ice extent on 11 February 2018.
There is a lot of high concentration sea ice between the ice edge and the iceberg that the ship will have to traverse. RRS James Clark Ross is a very capable ship, and she will be able to make way through the ice.
The issue is this can take a lot of time.
And time whilst ice breaking is fuel.
In open water a research ship can cover ~22 km per hour, in sea ice if you are breaking ice then maybe 5 km per hour would be good, and you probably wouldn’t break ice 24 hours per day.
They have 3 weeks.
Plus if you sail 400 km in the ice, unfavourable winds can easily compress the sea ice and trap a ship. It’s happened before, and in the modern era even capable ships get can get held up.
The satellite I used to make the image doesn’t do so well in coastal regions, so given some favourable winds there could be a nice channel for them. I am going to be watching the visible satellite imagery for that.
It’s easy to make pronouncements from 14,000 km away, but really the people on the ground will work it out.
Whatever happens I know that the researchers on board will do some great research. Plus I would be surprised if A68 moves too far from the region in the next year.
Breaking ice in Antarctica.
Breaking Antarctic sea ice on the RRS James Clark Ross.
(Apologies to the Rolling Stones for the title,
But if you try sometimes, you might find you get what you need.
*** Update 16 Feb 2028
This on twitter from Dr Stef Lhermitte
#MODIS Aqua of yesterday on https://t.co/RPVpONbwcO has a clear view (i.e. few clouds) of the area, nicely showing the high sea ice concentration and potential difficulty to reach iceberg #A68 pic.twitter.com/iti8tXmL6C
— Stef Lhermitte (@StefLhermitte) February 16, 2018
At the moment they will have to get through ~300 km of sea ice.
Posted in Science. Tags: A68, antarctica, Larsen C, RRS James Clark Ross, Science, sea ice on February 13, 2018 by Mark Brandon. Mark Brandon • November 24, 2017
Being interested in the Weddell Polynya I plotted some time series data from 1 September 2017 to 23 November 2017. On the left-hand panel, you can see the see the sea ice concentration, on the right-hand panel, the anomaly of the concentration each day compared with a mean from 1989-93.
The Weddell Polynya is the low concentration region at approximately 12:00 in the movies below.
You can see the Weddell Polynya isn’t stationary.
You can also see the sea ice is still relatively low compared to the historic record. We should expect this after the extreme low sea ice from ~October 2016 onward.
Antarctic sea ice extent (with greater >15% sea ice cover) 23 November 2017. From NSIDC.
I will write some more about this next week but for interest here is the Antarctic sea ice extent anomaly for 2017.
I made these movies using the excellent Antarctic Mapping Toolbox by Chad Greene. Antarctica is the Landsat Image Mosaic Of Antarctica (LIMA), and the coastline and shelf outlines come from the BEDMAP2 data set. Sea ice data is from NSDIC.
Posted in Science. Tags: anomaly, antarctica, sea ice, Weddell Polynya on November 24, 2017 by Mark Brandon. Mark Brandon • November 20, 2017
Antarctic sea ice extent remains low compared with the 1981-2010 median extent. This image shows the mean from 1989-93, the extent on 20 November 2017 and the difference between the two. Red colours imply that there is a decreased sea ice extent compared with the mean.
The mean Antarctic sea ice for the years 1989-93 on 20 Nov, the sea ice concentration on 20 Nov 2017 and the difference between the two data sets. Reds imply decreased sea ice compared with the mean, blue shades imply more. The original data come from the DMSP SMMI data set at the NSIDC.
And obvious low region is the vicinity of the Weddell Sea Polynya. I have written about the polynya this season on 17 September and 25 September, as well showing how it developed through the winter on 11 September 2017.
Something exciting is happening in the ocean under the polynya, and based on new data sources such as the SOCCOM buoy that surfaced in the polynya:
Last month, SOCCOM scientists were astonished to discover that a float in the Weddell Sea had surfaced inside the polynya, making contact with satellites in the dead of winter. Its new ocean measurements, transmitted when it surfaced, are being analyzed as part of a study in preparation on Weddell Sea polynyas. With these new observations comes the possibility that the polynya’s secrets may finally be revealed.
We should expect some exciting research articles soon.
Sea ice extent currently ~1.2 million km2 low
The overall sea ice extent is currently ~1.2 million km2 below 1981-2010 median extent. This sounds a lot.
Antarctic sea ice extent (with greater >15% sea ice cover) 18 November 2017. From NSIDC.
But at this time of the year the Antarctic sea ice is about to dramatically fall as spring develops. If spring “arrives” early then the extent will – as we see, be relatively low.
Seasonal cycle of Antarctic sea ice extent
Whilst the full on development and opening of the Weddell / Maud Rise Polynya is unusual, if you compare the sea ice on 18 November 2017 with the extent from the same day on 1989-1995 it is clear that the extent is often lower over Maud Rise, at this time.
This is the sea ice on 18 November for 1989, 91, 92, 93, 94, 95 and 18 November 2017. The original data come from the DMSP SMMI data set at the NSIDC.
I will keep watching the sea ice as the summer season develops
MODIS mosaic from the AQUA satellite on 18 November 2017.
** UPDATED 20th November 2017 replacing the first figure from 17 November to 20 November.
Posted in Science. Tags: antarctica, extent, Maud Rise, sea ice, SMMI, Weddell Polynya on November 20, 2017 by Mark Brandon. Mark Brandon • October 26, 2017
As daylight has returned to Antarctica it is straightforward to pick out polynya forming on the edge of the Antarctic continent.
This one by the Stange Ice Shelf and Rydberg Peninsula caught my eye. It is a latent heat polynya formed as the winds push the sea ice away from the land to reveal the ocean that appears black beneath.
The wispy trails of grey which appear in the black are new sea ice forming as frazil ice.
A latent heat polynya forming in front of the Rydberg Peninsula and Stange ice Shelf, 22-26 October 2017.
This is the location of the peninsula.
The location of the Rydberg Peninsula.
I visited that area in 2007 and took this picture. You can a thin skim of young nilas ice in front of the ice shelf, and sea smoke too.
The Stange Ice Shelf with a thin skim of sea ice in front. Posted in Science. Tags: antarctica, frazil ice, polynya, Rydberg Peninsula, satellite, sea smoke, Stange Ice shelf on October 26, 2017 by Mark Brandon. Mark Brandon • September 27, 2017
The polynya over Maud Rise was visible in a beautiful clear MODIS image on 25 September. It is currently ~40,000 km2 of open water in the middle of the Antarctic winter sea ice. This will be some impressive heat loss.
MODIS image of the polyna over Maud rise on 25 Sept 2017. The black is ~40,000km2 of open water.
This is the polynya in the SMMI Data for the same day.
Location of Maud Rise polynya 25 Sept 2017.
A while back I calculated the heat loss through 2,000 km2 of open water in the Arctic as being ~600 GW. This is about 20 times as much open water…
As I said then, the heat loss is making the surface waters denser, so they sink away from the surface
More to come on this I expect.
Posted in Science. Tags: antarctica, Maud Rise, polynya, Weddell Sea on September 27, 2017 by Mark Brandon. Mark Brandon • September 19, 2017
Quick post on the Maud Polynya in the Weddell Sea that I wrote about last week. This is the sea ice data 17 September 2017, and the polynya is both clear and large.
The location of the polynya over Maud Rise. Sea ice data from DMSP SMMI.
An enlargement of the polynya shows that it is practically open water.
…continue reading →
Posted in Science. Tags: antarctica, Maud Rise, polynya, sea ice, Weddell Polynya, Weddell Sea on September 19, 2017 by Mark Brandon. Mark Brandon • September 11, 2017
The Weddell Sea polynya is an area of open water that sometimes appears in the Weddell Sea over a relatively shallow region called Maud Rise.
The Antarctic sea ice concentration 9 September 2017. The location of the polynya is marked and the original data come from the DMSP SMMI data set at the NSIDC.
In the latest satellite imagery from the DMSP satellite you can see the lower concentration sea ice as the darker blue colour. If you look at the MODIS imagery for the same date you can clear see black which indicates open water in the pack ice.
The MODIS imagery mosaic of Antarctica from 7 September 2017 from the MODIS sensor on the Terra satellite. The pattern in the centre of the image is because high latitudes of Antarctica are still dark at this time in winter.
…continue reading →
Posted in Science. Tags: antarctica, Maud Rise, MODIS, polynya, satellite, SMMI, SMOS, Weddell Sea on September 11, 2017 by Mark Brandon. Mark Brandon • July 18, 2017
Project MIDAS shows us that the iceberg A68 is about one trillion tonnes.
This is the Antarctic Peninsula and the outline of A68 from the satellite image on 14 July 2017 shown in black. The ice front is from the Bedmap2 data set (so a little out of date), and the bathymetry from the IBCSO data set.
Larsen C Ice shelf on the Antarctic Peninsula and the location and area of iceberg A68. The outline of A68 is derived from a satellite image of the ice shelf 14 July 2017.
There are some astonishingly beautiful processed satellite images of A68 out there such as this one via ESA from Adrian Luckman and the excellent Project MIDAS.
One image I haven’t seen is how good is knowledge of the bathymetry around A68?
The iceberg is going to drift and likely ground quite quickly. (I wrote about this on the conversation a while ago: When an Antarctic iceberg the size of a country breaks away, what happens next?)
In the map below, the shaded colour is the distance of any point on the sea bed to the closest actual depth measurement.
The distance to the nearest good depth measurement around the Antarctic Peninsula.
So the dark blue stripes labelled in the Weddell Sea are actually ship tracks – and the dark colours are good depth data. These measurements will have been made by icebreaker.
Just in front of A68 there is a very large area where no ship has been within ~80 km.
One small note on the size. I digitized the iceberg from a satellite image (a KML File can be downloaded). On twitter today there were satellite images showing fractures already.
New crack on eastern side of Iceberg A68 carves out large chunk of ice, as berg moves further away from #LarsenC Ice Shelf @deimosimaging pic.twitter.com/NagHUSUuH8
— The Antarctic Report (@AntarcticReport) July 18, 2017
But Martin O’Leary of the MIDAS team posted today on twitter that to the untrained eye looks like iceberg, is very likely fast ice (so thick sea ice that is “fast” to A68 – but only a few metres thick.)
Pretty sure this is some fast ice (i.e. sea ice, maybe a few meters thick) detaching from the berg. Looks totally different in SAR imagery https://t.co/XHDGle0gVv
— Martin O’Leary (@mewo2) July 18, 2017
Posted in Science. Tags: A68, Antarctic Peninsula, antarctica, bathymetry, Larsen C, Weddell Sea on July 18, 2017 by Mark Brandon.
Being interested in the Weddell Polynya I plotted some time series data from 1 September 2017 to 23 November 2017. On the left-hand panel, you can see the see the sea ice concentration, on the right-hand panel, the anomaly of the concentration each day compared with a mean from 1989-93.
The Weddell Polynya is the low concentration region at approximately 12:00 in the movies below.
You can see the Weddell Polynya isn’t stationary.
You can also see the sea ice is still relatively low compared to the historic record. We should expect this after the extreme low sea ice from ~October 2016 onward.
Antarctic sea ice extent (with greater >15% sea ice cover) 23 November 2017. From NSIDC.
I will write some more about this next week but for interest here is the Antarctic sea ice extent anomaly for 2017.
I made these movies using the excellent Antarctic Mapping Toolbox by Chad Greene. Antarctica is the Landsat Image Mosaic Of Antarctica (LIMA), and the coastline and shelf outlines come from the BEDMAP2 data set. Sea ice data is from NSDIC.
Posted in Science. Tags: anomaly, antarctica, sea ice, Weddell Polynya on November 24, 2017 by Mark Brandon. Mark Brandon • November 20, 2017
Antarctic sea ice extent remains low compared with the 1981-2010 median extent. This image shows the mean from 1989-93, the extent on 20 November 2017 and the difference between the two. Red colours imply that there is a decreased sea ice extent compared with the mean.
The mean Antarctic sea ice for the years 1989-93 on 20 Nov, the sea ice concentration on 20 Nov 2017 and the difference between the two data sets. Reds imply decreased sea ice compared with the mean, blue shades imply more. The original data come from the DMSP SMMI data set at the NSIDC.
And obvious low region is the vicinity of the Weddell Sea Polynya. I have written about the polynya this season on 17 September and 25 September, as well showing how it developed through the winter on 11 September 2017.
Something exciting is happening in the ocean under the polynya, and based on new data sources such as the SOCCOM buoy that surfaced in the polynya:
Last month, SOCCOM scientists were astonished to discover that a float in the Weddell Sea had surfaced inside the polynya, making contact with satellites in the dead of winter. Its new ocean measurements, transmitted when it surfaced, are being analyzed as part of a study in preparation on Weddell Sea polynyas. With these new observations comes the possibility that the polynya’s secrets may finally be revealed.
We should expect some exciting research articles soon.
Sea ice extent currently ~1.2 million km2 low
The overall sea ice extent is currently ~1.2 million km2 below 1981-2010 median extent. This sounds a lot.
Antarctic sea ice extent (with greater >15% sea ice cover) 18 November 2017. From NSIDC.
But at this time of the year the Antarctic sea ice is about to dramatically fall as spring develops. If spring “arrives” early then the extent will – as we see, be relatively low.
Seasonal cycle of Antarctic sea ice extent
Whilst the full on development and opening of the Weddell / Maud Rise Polynya is unusual, if you compare the sea ice on 18 November 2017 with the extent from the same day on 1989-1995 it is clear that the extent is often lower over Maud Rise, at this time.
This is the sea ice on 18 November for 1989, 91, 92, 93, 94, 95 and 18 November 2017. The original data come from the DMSP SMMI data set at the NSIDC.
I will keep watching the sea ice as the summer season develops
MODIS mosaic from the AQUA satellite on 18 November 2017.
** UPDATED 20th November 2017 replacing the first figure from 17 November to 20 November.
Posted in Science. Tags: antarctica, extent, Maud Rise, sea ice, SMMI, Weddell Polynya on November 20, 2017 by Mark Brandon.
Greenland’s ice sheet suffered major melting in July 2019, dumping billions of tons of meltwater into the Atlantic Ocena. Jennifer Latuperisa-Andresen/Unsplash, CC BY-SA
Mark Brandon, The Open University
The Intergovernmental Panel on Climate Change (IPCC) – the UN body responsible for communicating the science of climate breakdown – has released its long-awaited Special Report on the Ocean and Cryosphere in a Changing Climate.
Based on almost 7,000 peer-reviewed research articles, the report is a cutting-edge crash course in how human-caused climate breakdown is changing our ice and oceans and what it means for humanity and the living planet. In a nutshell, the news isn’t good.
Most of us rarely come into contact with the cryosphere, but it is a critical part of our climate system. The term refers to the frozen parts of our planet – the great ice sheets of Greenland and Antarctica, the icebergs that break off and drift in the oceans, the glaciers on our high mountain ranges, our winter snow, the ice on lakes and the polar oceans, and the frozen ground in much of the Arctic landscape called permafrost.
Read more: What is the cryosphere? Hint: It’s vital to farming, fishing and skiing
The cryosphere is shrinking. Snow cover is reducing, glaciers and ice sheets are melting and permafrost is thawing. We’ve known this for most of my 25-year career, but the report highlights that melting is accelerating, with potentially disastrous consequences for humanity and marine and high mountain ecosystems.
At the moment, we’re on track to lose more than half of all the permafrost by the end of the century. Thousands of roads and buildings sit on this frozen soil – and their foundations are slowly transitioning to mud. Permafrost also stores almost twice the amount of carbon as is present in the atmosphere. While increased plant growth may be able to offset some of the release of carbon from newly thawed soils, much will be released to the atmosphere, significantly accelerating the pace of global heating.
Sea ice is declining rapidly, and an ice-free Arctic ocean will become a regular summer occurrence as things stand. Indigenous peoples who live in the Arctic are already having to change how they hunt and travel, and some coastal communities are already planning for relocation. Populations of seals, walruses, polar bears, whales and other mammals and sea birds who depend on the ice may crash if sea ice is regularly absent. And as water in its bright-white solid form is much more effective at reflecting heat from the sun, its rapid loss is also accelerating global heating.
Glaciers are also melting. If emissions continue on their current trajectory, smaller glaciers will shrink by more than 80% by the end of the century. This retreat will place increasing strain on the hundreds of millions of people globally who rely on glaciers for water, agriculture, and power. Dangerous landslides, avalanches, rockfalls and floods will become increasingly normal in mountain areas.
All this melting ice means that sea levels are rising. While seas rose globally by around 15cm during the 20th century, they’re now rising more than twice as fast –- and this rate is accelerating.
Thanks to research from myself and others, we now better understand how Antarctica and Greenland’s ice sheets interact with the oceans. As a result, the latest report has upgraded its long-term estimates for how much sea level is expected to rise. Uncertainties still remain, but we’re headed for a rise of between 60 and 110cm by 2100.
Arctic sea ice is melting at an unprecedented rate, contributing to sea level rise. Netta Arobas/Shutterstock
Of course, sea level isn’t static. Intense rainfall and cyclones – themselves exacerbated by climate breakdown – can cause water to surge metres above the normal level. The IPCC’s report is very clear: these extreme storm surges we used to expect once per century will now be expected every year by mid-century. In addition to rapidly curbing emissions, we must invest millions to protect at-risk coastal and low-lying areas from flooding and loss of life.
Up to now, the ocean has taken up more than 90% of the excess heat in the global climate system. Warming to date has already reduced the mixing between water layers and, as a consequence, has reduced the supply of oxygen and nutrients for marine life. By 2100 the ocean will take up five to seven times more heat than it has done in the past 50 years if we don’t change our emissions trajectory. Marine heatwaves are also projected to be more intense, last longer and occur 50 times more often. To top it off, the ocean is becoming more acidic as it continues to absorb a proportion of the carbon dioxide we emit.
Collectively, these pressures place marine life across the globe under unprecedented threat. Some species may move to new waters, but others less able to adapt will decline or even die out. This could cause major problems for communities that depend on local seafood. As it stands, coral reefs – beautiful ecosystems that support thousands of species – will be nearly totally wiped out by the end of the century.
While the document makes some striking statements, it is actually relatively conservative with its conclusions – perhaps because it had to be approved by the 195 nations that ratify the IPCC’s reports. Right now, I would expect that sea level rise and ice melt will occur faster than the report predicts. Ten years ago, I might have said the opposite. But the latest science is painting an increasingly grave picture for the future of our oceans and cryosphere – particularly if we carry on with “business as usual”.
Read more: Not convinced on the need for urgent climate action? Here’s what happens to our planet between 1.5°C and 2°C of global warming
The difference between 1.5°C and 2°C of heating is especially important for the icy poles, which warm much faster than the global average. At 1.5°C of warming, the probability of an ice-free September in the Arctic ocean is one in 100. But at 2°C, we’d expect to see this happening about one-third of the time. Rising sea levels, ocean warming and acidification, melting glaciers, and permafrost also will also happen faster – and with it, the risks to humanity and the living planet increase. It’s up to us and the leaders we choose to stem the rising tide of climate and ecological breakdown.
Mark Brandon, Professor of Polar Oceanography, The Open University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
The South West Atlantic is a very productive part of the global ocean. This MODIS image from the Terra satellite shows the east coast of Argentina and the Falkland Islands. The ocean between is filled with swirls of lighter colour which are a plankton bloom along the continental shelf of South America.
Terra/MODIS Image captured 21 January 2015 14:00 UTC. FULL IMAGE LINK
The high plankton productivity means that there is food for the higher predators – and this region is famed as an extraordinarily rich squid fishing ground. In 2014 the fishery apparently took over 1/4 million tons of the squid Illex argentinus.
…continue reading →
Posted in Science. Tags: Argentina, Falkland Islands, Illex argentinus, oceanography, South Atlantic, squid on January 28, 2015 by Mark Brandon. Mark Brandon • January 19, 2015 Captain Robert Falcon Scott
“England knows Scott as a hero; she has little idea of him as a man. He was certainly the most dominating character in our not uninteresting community: indeed, there is no doubt that he would carry weight in any gathering of human beings. But few who knew him realized how shy and reserved the man was, and it was partly for this reason that he so often laid himself open to misunderstanding.
Add to this that he was sensitive, femininely sensitive, to a degree which might be considered a fault, and it will be clear that leadership to such a man may be almost a martyrdom, and that the confidence so necessary between leader and followers, which must of necessity be based upon mutual knowledge and trust, becomes in itself more difficult. It wanted an understanding man to appreciate Scott quickly; to others knowledge came with experience.
He was not a very strong man physically, and was in his youth a weakly child, at one time not expected to live. But he was well proportioned, with broad shoulders and a good chest, a stronger man than Wilson, weaker than Bowers or Seaman Evans. He suffered from indigestion, and told me at the top of the Beardmore that he never expected to go on during the first stage of the ascent.
Temperamentally he was a weak man, and might very easily have been an irritable autocrat. As it was he had moods and depressions which might last for weeks, and of these there is ample evidence in his diary. The man with the nerves gets things done, but sometimes he has a terrible time in doing them. He cried more easily than any man I have ever known.
What pulled Scott through was character, sheer good grain, which ran over and under and through his weaker self and clamped it together. It would be stupid to say he had all the virtues: he had, for instance, little sense of humour, and he was a bad judge of men. But you have only to read one page of what he wrote towards the end to see something of his sense of justice. For him justice was God. Indeed I think you must read all those pages; and if you have read them once, you will probably read them again. You will not need much imagination to see what manner of man he was.
And notwithstanding the immense fits of depression which attacked him, Scott was the strongest combination of a strong mind in a strong body that I have ever known. And this because he was so weak! Naturally so peevish, highly strung, irritable, depressed and moody. Practically such a conquest of himself, such vitality, such push and determination, and withal in himself such personal and magnetic charm. He was naturally an idle man, he has told us so;[134] he had been a poor man, and he had a horror of leaving those dependent upon him in difficulties. You may read it over and over again in his last letters and messages.[135]
He will go down to history as the Englishman who conquered the South Pole and who died as fine a death as any man has had the honour to die. His triumphs are many—but the Pole was not by any means the greatest of them. Surely the greatest was that by which he conquered his weaker self, and became the strong leader whom we went to follow and came to love.”
Apsley Cherry Garrard wrote that in the Worst Journey in the World.
Captain Scott was a complex man.
Posted in History. Tags: antarctica, Apsley Cherry-Garrard, history, Leadership, Scott, The Worst Journey in the World on January 19, 2015 by Mark Brandon.
I keep seeing a map of Antarctica with an overlaid outline of the United States. I thought it would be helpful to have a picture of the continent compared with the size of Europe.
Antarctica compared with the size of Europe
This is a picture from a book I wrote half of and edited a long time ago.
It always struck me as strange that Antarctica being the “coldest and windiest place” is constantly recycled. The picture shows it is a huge place and it does not have one single climate.
On the Antarctic Peninsula it is relatively mild. It’s even referred to sometimes as being the “banana belt”. But away from the heat of the ocean, and high on the plateau it is without doubt cold almost beyond comprehension.
But one thing is for sure: there is no representative Antarctic climate.
My previous posts on Amundsen Sea Polynya and their development showed ~37,600 km2 of open water in front of the ice shelves. It is very early spring in Antarctica at this time of the year and it’s still cold.
That means sea ice can still grow.
This is the Dotson Getz polynya on 9 October 2016. It has a perimeter of ~800 km and an area of ~25,500 km2.
The Dotson Getz polynya on 9 October 2016. Open water is black and streaks of sea ice growth are clear. The location of the Bear Peninsula Automatic Weather Station is marked.
I put together the satellite data from 9-12 October 2016 and it shows extremely rapid sea ice growth.
…continue reading →
Posted in Science. Tags: Amundsen Sea, Antarctic, Dotson Ice Shelf, frazil ice, MODIS, polynya, sea ice on October 13, 2016 by Mark Brandon. Mark Brandon • October 12, 2016
I was interested in how long the polynya I blogged about yesterday had existed.
I made a gif of the previous months sea ice data.
The sea ice extent in Pine Island Bay 11 September to 10 October 2016. Data from DMSP SSMI. The development of the polynya can be seen in the growth of the dark regions.
You can see that the polynya in the centre of the picture can be seen from the very beginning. This is forming in front of the Dotson Ice Shelf – and from the scale bar you can see it is big. This polynya really starts to develop as open water around 5 October 2016.
The coastal polynya on the northern land boundary appear in mid September – and develop throughout the record.
The image below was in my previous post and it shows the three polynya from a MODIS image on 9 October 2016.
The MODIS imagery 9 October 2016 from the TERRA satellite overlain in Google Earth
Next diversion will be a area of open water / time plot.
Posted in Science. Tags: Amundsen Sea, Amundsen Sea Embayment, antarctica, Dotson Ice Shelf, Pine Island, polynya, satellite, sea ice on October 12, 2016 by Mark Brandon. Mark Brandon • October 11, 2016
The Amundsen Sea currently has some very large polynya. In front of the Dotson, Getz and Pine Island ice shelves they are clear in the satellite data.
The sea ice extent along the Antarctic Peninsula 9 October 2016. Data from DMSP SSMI.
A polynya is an area of open water in the winter pack ice.
These are likely latent heat polynya, and strong winds are pushing the sea ice away from the coasts to make the open water. In the open water there will be a lot of sea ice generation. I wouldn’t be surprised if the weather that is keeping the sea ice compressed against the Antarctic Peninsula is also responsible for opening them.
Taking the MODIS data from the TERRA satellite and importing that into google earth, the open water shows up as black. At the top of the image in front of Pine Island Glacier the polynya are partially obscured by cloud.
In Google Earth you can measure the area quite easily.
…continue reading →
Posted in Science. Tags: Amundsen Sea, antarctica, Dotson Ice Shelf, google earth, Kohler Glacier, polynya, satellite, sensible heat loss, Smith Glacier on October 11, 2016 by Mark Brandon. Mark Brandon • October 7, 2016
It is October and it is the Arctic sea ice growing season. The MODIS imagery yesterday shows this beautiful image of sea ice on the North East Greenland coast.
North East Greenland in a MODIS image 5 October 2016 from the TERRA satellite
The image below shows roughly where we are looking:
…continue reading →
Posted in Science. Tags: Arctic, Greenland, MODIS, Nansen, satellite, sea ice, transpolar drift stream on October 7, 2016 by Mark Brandon. Mark Brandon • October 6, 2016
I’ve been watching the open water down the eastern side of the Antarctic Peninsula. I said the cause of that was most likely strong westerly winds.
If you look at the sea ice concentration on the western Antarctic Peninsula you can see the effect of these westerly winds.
Towards the end of September 2016 the ice edge is compacted as the sea ice is pushed against the Peninsula.
The Antarctic Peninsula sea ice 24 August to 5 October 2016. Data from DMSP SSMI
The westerly winds (from bottom left to top right) compress the sea ice against the land (left hand side of the Antarctic Peninsula). This also creates open water on the eastern (right hand side ) of the Peninsula as the sea ice is pushed away from the land.
You can see the very sharp ice edge on the west, and the open open water in the MODIS satellite imagery.
MODIS image of the Antarctic Peninsula 5 October 2016 from the Aqua satellite.
The sea ice concentration anomaly for September 2016 shows that on both sides of the Antarctic Peninsula the westerly winds have reduced the amount of ice we would expect to observe by up to ~40%. On the west side because the sea ice is compressed, on the east side because the sea ice is being pushed away from the land.
Antarctic sea ice concentration anomaly for Sep 2016. Yellow rectangle approx area of images above. Image from NSIDC
This is just late winter weather.
There are a lot of Antarctic research stations on the west of the Antarctic Peninsula, including Rothera, the largest British Base. If the winds maintain the westerly direction then I can imagine it could be slow to resupply the base this season. There is time for it to change. According to the published schedule the ship is not due to arrive until 27 November 2016.
A slow resupply is not uncommon and I have been on at least one unsuccessful resupply voyage in my career. I took the picture below on 11 December 2004 under similar conditions.
RRS James Clark Ross making very slow progress in compressed sea ice in Marguerite Bay, the Western Antarctic Peninsula 11 December 2004. Posted in Science. Tags: Antarctic Peninsula, James Clark Ross, Marguerite Bay, Rothera, satellite, Science, sea ice, Weddell Sea on October 6, 2016 by Mark Brandon. Mark Brandon • October 3, 2016
I noticed in a blog post last week that there was a finger of open water extending down the Western Weddell Sea. I’ve carried on watching this open water in the MODIS satellite data. Whilst it’s been opening and closing, there is a lot of open water. It’s clearly a major sea ice generating factory at the moment.
MODIS image of the Western Weddell Sea 30 September 2016. The Open Water is clear.
The open water is clear in the lower resolution passive microwave sea ice data too.
The sea ice extent along the Antarctic Peninsula 2 October 2016. Data from DMSP SSMI
If you look at some model output there are air temperatures above this open water of between -10° to about -25°C.
Surface temperature at 2m from NCEP output. 3 October 2016. From Climate Reanalyzer.org
What is really good is if you look at the temperature anomaly (i.e. the departure from the average with a 1979-2000 baseline), it is very warm over the Weddell Sea.
The temperature departure from average for NCEP output 3 October 2016. Image from climateReanalyzer.org.
I think the reason it is warmer is because the Weddell Sea pack ice is looser this year. So (as you can see in the picture above) there is lots of open water. The atmosphere is being warmed by the ocean as the sea ice is being generated.
Another pointer to the pack being looser this year is that in August 2016 in the Eastern Weddell Sea there was a rare sighting of the Weddell Polynya.
The Weddell Polynya as observed on 14 August 2016 in passive satellite data. It is a polynya with its own wikipedia page.
I think the Weddell Sea pack ice is more mobile this winter. This is also telling us something about the difference between sea ice extent and sea ice thickness. The sea ice extent is large and easy to measure in the Antarctic – but we don’t know how thick it is.
Posted in Science. Tags: Antarctic, Antarctic Peninsula, MODIS, polynya, satellite, Science, sea ice, Weddell Sea on October 3, 2016 by Mark Brandon.
I came across this brilliant Deep Sea News blog post about oil on troubled waters. It talks at length about how a surface film of oil damps out higher frequency surface waves and only the low frequency waves can propagate. The net effect is the sea feels calmer as the breaking waves are damped out.
The same thing happens in rough seas when ice forms. I took the picture below in Bellingshausen Sea.
A grease ice slick in the Bellingshausen Sea Antarctica
What you are looking at is very thin slick made up of sea ice crystals in the open ocean (called grease ice). The layer of crystals only allows the low frequency waves to propagate – so you see these odd looking slowly propagating ripples.
…continue reading →
Posted in Science. Tags: Antarctic, polar, satellite, sea ice on November 19, 2013 by Mark Brandon.
Posted in Science, Storify, twitter. Tags: Arctic, Gavin Schmidt, Methane, Royal Society, sea ice, storify, twitter on September 30, 2014 by Mark Brandon. Mark Brandon • March 3, 2014
Last week the Royal Society (UK), and the National Academy of Sciences (NAS) released a good PDF booklet called Climate Change: Evidence & Causes.
In the words of the US NAS
“Climate Change makes clear what is well-established and where understanding is still developing. It echoes and builds upon the long history of climate-related work from both national academies.”
You can read the background at the Royal Society site, and Carbon Brief provides a synopsis so good I can’t add much.
But I will talk about the cover. Here is a screen grab.
The Cover of the Royal Society Climate Change report
I think it’s beautiful. I love the way the golden light reflects on the young sea ice. In fact I think it is so beautiful that we used it on the cover of a book I partially wrote and edited for my employer in 2011.
The Cover of the Open University Frozen Planet Coursebook
The original is an iStock image called “Polar bear on ice close to golden glittering water”. Now that is not what I would call it – but then I wasn’t fortunate enough to be in a helicopter at that time of the year, and so I don’t get to choose.
The Royal Society / NAS had cropped the bear from the image so they used the segment in the yellow rectangle below…
The cover of the S175 Book with the crop
They actually rotated and stretched it slightly to completely miss the bear – although there are still clearly bear footprints in the version they use.
I am sure they did that because they did not want to get into the whole “poor polar bear looking over the melting ice” conversation. All the way back in 2012 Carbon Brief included “sad polar bear on melting ice” as one of their Nine climate change pictures I really don’t need to see again.
So why did I use it? To me the polar bear is in its natural habitat. The bear is wandering over decaying sea ice and refrozen melt water. Our book is filled with the science of how and why the ice grows and melts, and what adaptations and strategies the animals use to survive, plus lots of other science. The polar bear’s Latin name is ursus maritimus – which in English is “sea bear”: open water and ice are part of their habitat.
That nuance is not possible in a short but excellent PDF report on climate change, so
I imagine they chose the beautiful light.
In hindsight I think I would have used another image. But only because if you go to the trouble of writing a book, then you would want to keep it special.
The problem I had at the time was that I was not very good at choosing any of my own images.
–
The title of the post points to the book Setting Free the Bears by John Irving. It’s a book I like and it is about two young people releasing the animals from Vienna zoo after the Second World War.
Posted in Science. Tags: Arctic, climate change, Frozen Planet, polar bear, Royal Society, sea ice on March 3, 2014 by Mark Brandon.
In the previous post I made a plot of Antarctica and compared it to the size of Europe. I made the throwaway point that it was unreasonable to imagine Antarctica as being characterized with one climatic zone. It is not all the “coldest and windiest place” on Earth.
I thought a simple example would show what I mean:
I got the mean monthly temperatures at two Antarctic Stations from the NOAA NCDC GCPS MONTHLY STATION data available from IRI/LDEO Climate Data Library.
I chose Adelaide Island and Vostok, and picked monthly data from December 1964 to December 1966.
The mean monthly temperature at Adelaide Island and Vostok station
Adelaide island is on the coast and it astonishingly beautiful. The data I used were collected at the British Antarctic Survey BASE T.
In contrast Vostok station is quite literally an icy waste in the middle of nowhere (* but see below).
This plot shows their relative locations in relation to the South Pole.
The locations of Adelaide Island, Vostok, and South Pole
You can see that at Adelaide Island – which is at sea level and coastal – the seasonal cycle is relatively narrow and only about 11°C. Temperatures are above 0°C in the summer.
At Vostok – which is on the East Antarctic Ice Sheet and at an altitude of about 3700m – the seasonal cycle is vast. In the Antarctic summer the temperatures are about -30°C, whereas in winter the temperatures fall and it is scarily cold (monthly mean -71.4°C in August 1966!).
If you want to know why Adelaide Island has a relatively small seasonal cycle, whereas Vostok seems to have a squashed “U” shape temperature cycle, then you have to understand something about the basic meteorology of the Antarctic Regions. (As an aside then you would understand why this happens in winter).
In a later post I may say something about how the climate is changing across Antarctica over the last 50-60 years. The spoiler on that is at on the Antarctic Peninsula it has changed a lot – in the range “4-5°C”,and the changes are impacting the ocean system, whereas at Vostok it has not.
* – of course Vostok isn’t really in the middle of “nowhere”. It is over the vast and hugely significant under ice Lake Vostok, and is the location of the first great Antarctic ice core – the Vostok Ice Core.
Posted in Science. Tags: antarctica, British Antarctic Survey, temperature, Vostok on January 31, 2014 by Mark Brandon. Mark Brandon • January 30, 2014
I keep seeing a map of Antarctica with an overlaid outline of the United States. I thought it would be helpful to have a picture of the continent compared with the size of Europe.
Antarctica compared with the size of Europe
This is a picture from a book I wrote half of and edited a long time ago.
It always struck me as strange that Antarctica being the “coldest and windiest place” is constantly recycled. The picture shows it is a huge place and it does not have one single climate.
On the Antarctic Peninsula it is relatively mild. It’s even referred to sometimes as being the “banana belt”. But away from the heat of the ocean, and high on the plateau it is without doubt cold almost beyond comprehension.
But one thing is for sure: there is no representative Antarctic climate.
Posted in Science. Tags: antarctica, climate, map, Science on January 30, 2014 by Mark Brandon. Mark Brandon • January 28, 2014
I don’t usually work on this sort of thing, but very recently I have been writing about hazards caused by the cryosphere. A major hazard is of course the avalanche – whether ice, snow, or a mixture.
This video was posted on You tube (with the tag line “Courtesy Vertical Solutions”), and it shows the impact of a snow and ice avalanche on the Alaskan road network on the 26 January 2014.
I tweeted it yesterday and the glaciologist Mauri Pelto replied
@icey_mark That is Richardson Highway that is flooded now, if this releases as one would expect in a torrent, the highway will fair worse.
— Mauri Pelto (@realglacier) January 27, 2014
I’ll try to remember to keep an eye online to see the outcome.
Posted in Science. Tags: Alaska, Arctic, avalanche, youtube on January 28, 2014 by Mark Brandon.
The Prince Gustav Channel early spring Antarctic summer 2016/7 from MODIS satellite imagery on the TERRA satellite.
The Antarctic Peninsula showing the location of the Prince Gustav Channel.
A basemap with a MODIS image from 7 October 2024. The yellow box is the location of Antarctic Sound and is expanded on below.
A MODIS satellite image of Antarctic Sound taken on 7 October 2024. Two large icebergs are at the southern end of the Sound. These are A80A and A76C.
A Sentinel-1 SAR image from 8 October 2024. Land is coloured blue, the giant icebergs are solid grey, and sea ice and smaller icebergs make up the grey shades colouring the rest of the image.
A MODIS satellite image from 13 October 2024 showing iceberg A23A just north of the South Orkney Islands.
Corrected Reflectance (True Color) from the Suomi NPP Visible Infrared Imaging Radiometer Suite (VIIRS), and the Brightness Temperature (Band I5, Day). Image from 20 August 2018.
Iceberg A68 and the Larsen C Ice shelf captured from with the Sentinel-1 SAR sensor 11 February 2018.
Antarctic Sea ice.
Larsen C, the iceberg A68 and the sea ice extent on 11 February 2018.
Breaking Antarctic sea ice on the RRS James Clark Ross.
Antarctic sea ice extent (with greater >15% sea ice cover) 23 November 2017. From NSIDC.
The mean Antarctic sea ice for the years 1989-93 on 20 Nov, the sea ice concentration on 20 Nov 2017 and the difference between the two data sets. Reds imply decreased sea ice compared with the mean, blue shades imply more. The original data come from the DMSP SMMI data set at the NSIDC.
Antarctic sea ice extent (with greater >15% sea ice cover) 18 November 2017. From NSIDC.
Seasonal cycle of Antarctic sea ice extent
This is the sea ice on 18 November for 1989, 91, 92, 93, 94, 95 and 18 November 2017. The original data come from the DMSP SMMI data set at the NSIDC.
MODIS mosaic from the AQUA satellite on 18 November 2017.
A latent heat polynya forming in front of the Rydberg Peninsula and Stange ice Shelf, 22-26 October 2017.
The location of the Rydberg Peninsula.
The Stange Ice Shelf with a thin skim of sea ice in front. Posted in Science. Tags: antarctica, frazil ice, polynya, Rydberg Peninsula, satellite, sea smoke, Stange Ice shelf on October 26, 2017 by Mark Brandon. Mark Brandon • September 27, 2017
MODIS image of the polyna over Maud rise on 25 Sept 2017. The black is ~40,000km2 of open water.
Location of Maud Rise polynya 25 Sept 2017.
The location of the polynya over Maud Rise. Sea ice data from DMSP SMMI.
The Antarctic sea ice concentration 9 September 2017. The location of the polynya is marked and the original data come from the DMSP SMMI data set at the NSIDC.
The MODIS imagery mosaic of Antarctica from 7 September 2017 from the MODIS sensor on the Terra satellite. The pattern in the centre of the image is because high latitudes of Antarctica are still dark at this time in winter.
Larsen C Ice shelf on the Antarctic Peninsula and the location and area of iceberg A68. The outline of A68 is derived from a satellite image of the ice shelf 14 July 2017.
The distance to the nearest good depth measurement around the Antarctic Peninsula.
Greenland’s ice sheet suffered major melting in July 2019, dumping billions of tons of meltwater into the Atlantic Ocena. Jennifer Latuperisa-Andresen/Unsplash, CC BY-SA
Arctic sea ice is melting at an unprecedented rate, contributing to sea level rise. Netta Arobas/Shutterstock
Terra/MODIS Image captured 21 January 2015 14:00 UTC. FULL IMAGE LINK
Captain Robert Falcon Scott
Antarctica compared with the size of Europe
The Dotson Getz polynya on 9 October 2016. Open water is black and streaks of sea ice growth are clear. The location of the Bear Peninsula Automatic Weather Station is marked.
The sea ice extent in Pine Island Bay 11 September to 10 October 2016. Data from DMSP SSMI. The development of the polynya can be seen in the growth of the dark regions.
The MODIS imagery 9 October 2016 from the TERRA satellite overlain in Google Earth
The sea ice extent along the Antarctic Peninsula 9 October 2016. Data from DMSP SSMI.
North East Greenland in a MODIS image 5 October 2016 from the TERRA satellite
The Antarctic Peninsula sea ice 24 August to 5 October 2016. Data from DMSP SSMI
MODIS image of the Antarctic Peninsula 5 October 2016 from the Aqua satellite.
Antarctic sea ice concentration anomaly for Sep 2016. Yellow rectangle approx area of images above. Image from NSIDC
RRS James Clark Ross making very slow progress in compressed sea ice in Marguerite Bay, the Western Antarctic Peninsula 11 December 2004. Posted in Science. Tags: Antarctic Peninsula, James Clark Ross, Marguerite Bay, Rothera, satellite, Science, sea ice, Weddell Sea on October 6, 2016 by Mark Brandon. Mark Brandon • October 3, 2016
MODIS image of the Western Weddell Sea 30 September 2016. The Open Water is clear.
The sea ice extent along the Antarctic Peninsula 2 October 2016. Data from DMSP SSMI
Surface temperature at 2m from NCEP output. 3 October 2016. From Climate Reanalyzer.org
The temperature departure from average for NCEP output 3 October 2016. Image from climateReanalyzer.org.
The Weddell Polynya as observed on 14 August 2016 in passive satellite data. It is a polynya with its own wikipedia page.
A grease ice slick in the Bellingshausen Sea Antarctica
The Cover of the Royal Society Climate Change report
The Cover of the Open University Frozen Planet Coursebook
The cover of the S175 Book with the crop
The mean monthly temperature at Adelaide Island and Vostok station
The locations of Adelaide Island, Vostok, and South Pole