by Judith Curry
I’m scratching me head over this one.
Last week (4/17), I received an email from a commercial pilot:
I have taken some pictures on my last flight that show some oceanic conditions that I have not seen before and I wonder if you might be able to enlighten me about what they are.
For many years I have been flying international trips across the Atlantic. Our routing varies daily, based on atmospheric conditions such as wind patterns and and turbulence. Our tracks vary from as far north as Iceland and southern Greenland or as far south as the Azores. Much of the time the ocean surface is not visible due to the flights being at night or the presence of an undercast cloud layer. On Tuesday, April 14, the skies below were clear and I took the attached photos that displayed sea conditions that I have not seen before.
I have seen icebergs coming from Greenland and all the way down the Canadian coast as well as ice floes along the shore. These pictures were taken at about N48 W048. We were headed approximately westbound so the left of the photos are to the south and the right toward the north. This formation extended as far as could be seen to the north. It appeared flat in nature.
It seemed very unusual. It was both long yet not very wide. Also, it seemed early in the year with no noticeable bergs and farther east and south than I have seen.
East to west maybe 20 miles or so. We were near the southern tip and it extended well to the north (maybe 100 miles or more). Pictures were taken at 35000 ft.
Here are the pictures:
Two days later (4/19), I received another email:
I was hoping our flight today would be near the vicinity of the previous photos. We were farther north this time but the clouds did break up as we approached Canada and I was able to take some more photos to forward. These were taken at approximately N54 W053.5. The first two are looking out the side to the south, so the left is east and the right is west. The third is looking north so the left is west and the right is to the east. Again, our altitude was 35,000 feet.
These are the typical ice patterns I am used to seeing at sea as we start to approach the Canadian coast. I have always thought that they had interesting flow/swirl patterns. I know so little about the ocean but I always assumed that they had something to do with currents and winds and tides.
What made me so curious about the first group that I sent you was their position so far from the coast as well as their narrow width and long length extending so far south. As I mentioned, I know very little about the ocean but I seem to remember something about a north/south current that exchanges warm and cold water somewhere in the Atlantic. I thought maybe there might be a fairly narrow current heading south that would be cold enough to keep them from melting.
Well, it seems to me that there are 3 possible choices:
- sea ice or ice bergs
- low level clouds
- surface spume (here are some google images)
The 3rd and 4th figures look like this could be cloud, but the first two figures don’t look like cloud.
Very far south for sea ice; the pattern doesn’t look like ice bergs?
Some sort of surface spume, associated with what, I don’t know, seems a possibility.
In any event, this feature seems to indicate some interesting mesoscale circulations in the ocean.
Have any of you ever seen anything like this? I guess when I fly across the Atlantic it is generally dark and I’m trying to sleep. I will send this to a few oceanographer friends to see what they think.