Day 1 of my voyage to the #Antarctic Peninsula on the #tallship #BarkEuropa: departing from #Ushuaia and sailing east along the Beagle Channel.
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Day 15 of my voyage to the #Antarctic Peninsula on the #tallship #BarkEuropa: riding the waves across Drake Passage with Bark Europa in full sail, viewed from near the wheelhouse.
@PoLaRobs What a wonderful adventure!
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@PoLaRobs
Nice! But is it safe? Lots of things have happened in the last 200 years, like Climate Change and big, smelly ships that will run straight through you. Also, are you equipped with GPS?@adrianmorales @PoLaRobs further to all the GPS's, it broadcasts it's position to other ships (AIS, i.e. can lookup IMO 8951932 on marinetraffic or vesselfinder and see where this boat is), and the wheelhouse has the basic set of modern safety electronics (chart plotter, echo sounder, radar).
Collisions can and do still happen, but this one is not much better or worse off than any others.
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I'd seen Cape Horn once before, from above on a flight 12 years ago on the British Antarctic Survey Dash7 aircraft, going from Punta Arenas, #Chile to Rothera Research Station on the #Antarctic Peninsula.
Day 17, the final day, of my voyage to the #Antarctic Peninsula on the #tallship #BarkEuropa: returning along the Beagle Channel to Ushuaia, from where we had set out. There I was able to pay my respects to the bust of Adrien De Gerlache, who led the Belgica expedition of 1897-1899 on which much of the area we had visited was first charted. Like Bark Europa, the Belgica was a three-masted bark, but a little smaller. The Belgica also called at Ushuaia in the last few days of 1897 before heading to Antarctica. Finally, I joined many of the other voyage crew in the Patagonia bar to reminisce on our shared adventure.
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The stand-out sights of this small boat excursion were a number of Weddell seals resting on some of the bergy bits.
@PoLaRobs Awww, I visited a seal sanctuary yesterday, and those chonki bois are just so amazing!!
(Not Weddel seals, just common and grey) -
A lot of melting was taking place when we visited Stony Point. Of course, this was summer in Antarctica, so some melting was expected. However, temperatures on this day and through January as a whole were 1 to 2°C above the recent average, which itself is a couple of degrees warmer than in the mid-20th century. Later this day the dry air temperature recorded on Bark Europa in neighbouring Andvord Bay was 3.8°C. Average 21st century January temperature at the US Palmer Station on Anvers Island is 2.7°C.
@PoLaRobs I wonder how you feel about the theory of my former colleague Gene Domack (perhaps not his theory, but he was the first to share it with me) that increased meal from Antarctica will increase sea ice cover by freshening the surface waters around the peninsula and effectively raising ice's melting point.
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Day 10 of my voyage to the #Antarctic Peninsula on the #tallship #BarkEuropa: landing on Jougla Point, a location formerly used by Whalers and literally a stone's throw away from the island where the former British base of Port Lockroy is located.
#BusmansHoliday@PoLaRobs third shot especially poignant
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@PoLaRobs I wonder how you feel about the theory of my former colleague Gene Domack (perhaps not his theory, but he was the first to share it with me) that increased meal from Antarctica will increase sea ice cover by freshening the surface waters around the peninsula and effectively raising ice's melting point.
@Brad_Rosenheim I think that theory has been the basis of several high profile papers. If there was any truth in it then sea ice extent west of the Peninsula and in the southern Bellingshausen Sea should have been increasing over the past few decades. In reality there has been a steady decline in sea-ice extent in these areas through the period of the satellite record, even while extent was steady or slightly increasing in other sectors up to 10 years ago.
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@Brad_Rosenheim I think that theory has been the basis of several high profile papers. If there was any truth in it then sea ice extent west of the Peninsula and in the southern Bellingshausen Sea should have been increasing over the past few decades. In reality there has been a steady decline in sea-ice extent in these areas through the period of the satellite record, even while extent was steady or slightly increasing in other sectors up to 10 years ago.
@PoLaRobs I think I've chatted with @carlosmoffat about it before, and he does the kind of modeling that would be important in assessing if this was happening.
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@Brad_Rosenheim I think that theory has been the basis of several high profile papers. If there was any truth in it then sea ice extent west of the Peninsula and in the southern Bellingshausen Sea should have been increasing over the past few decades. In reality there has been a steady decline in sea-ice extent in these areas through the period of the satellite record, even while extent was steady or slightly increasing in other sectors up to 10 years ago.
@Brad_Rosenheim
A further thought on this. The average surface water salinity in the Southern Ocean is about 34.5 ppt, which depresses the freezing point by nearly 2°C. If a large flux of melt decreases the salinity by 1 or 2 ppt, as happens around the sea ice edge when it is retreating in Spring, this raises the freezing point by around 0.1°C. I think other factors, including atmospheric and ocean temperatures and winds, are likely to be much more important in controlling sea ice extent. Furthermore, any melt added to the surface water in summer will be mixed into the upper ~200 m of the ocean by autumn storms before it can have much effect on new sea ice growth. -
@Brad_Rosenheim
A further thought on this. The average surface water salinity in the Southern Ocean is about 34.5 ppt, which depresses the freezing point by nearly 2°C. If a large flux of melt decreases the salinity by 1 or 2 ppt, as happens around the sea ice edge when it is retreating in Spring, this raises the freezing point by around 0.1°C. I think other factors, including atmospheric and ocean temperatures and winds, are likely to be much more important in controlling sea ice extent. Furthermore, any melt added to the surface water in summer will be mixed into the upper ~200 m of the ocean by autumn storms before it can have much effect on new sea ice growth.@PoLaRobs Yes, it would have to be a shirt term and localized effect at best, but the formation of ice, of course, would then limit vertical wind-driven mixing, making potentially more interesting.
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@PoLaRobs I think I've chatted with @carlosmoffat about it before, and he does the kind of modeling that would be important in assessing if this was happening.
@Brad_Rosenheim @carlosmoffat
I chatted with Carlos about this and other matters when he was visiting BAS a couple of years ago. If I remember correctly his view was that upwelling and mixing of CDW into surface waters was an important factor. -
J jwcph@helvede.net shared this topic
