On May 2 temperatures at the Pole (north of 80° north latitude) have dipped below normal for the first time since last fall. This is ahead of my prediction, was for it to happen on May 13.
My own theory is that the cooler temperatures are a response to the “Quiet Sun.” Therefore they are noticeable when the sun is up in the arctic sky. When the sun is below the horizon it can have no direct effect on temperatures. But it does have an indirect effect by creating a more meridional jet stream, which brings more mild air to the Pole.
I theorize that the “Quiet Sun’s” effect at the equator is counter-intuitive, for the equator is warmed by less energy. This occurs because the lack of energy manifests as less wind. When the easterlies slow there is less upwelling of cold water on the west coasts of continents at the equator, because less surface water is pushed to the west, away from those coasts. In the Pacific this is conducive to El Nino situations, but not conducive to La Ninas. Consequently the El Ninos will be amplified as the La Ninas are suppressed. La Ninas will not cease altogether, but they will have less bang for their buck. In general, the tropics will get warmer even as the Pole chills, which is what creates the imbalance that makes the jet stream meridional.
Last year the lagged effects of the 2015 El Nino nearly hid the effect of the chilled Pole. Only at the height of summer were temperatures below normal at the Pole.
The year before, (and also in 2007-2014) when there were no lagged effects of a very strong El Nino, temperatures dipped below normal as soon as the sun started to have an appreciable effect north of the Arctic Circle.
In conclusion, though my logic may seem too simplistic to some, I confess to what it is, (especially when it works).
I should also note the past La Nina failed to be as strong as we initially thought it might be, and it looks like we may be headed back to an El Nino situation, (even if it is not especially strong.) SST temperatures in the tropics are above normal. Further north they are not above normal, which could contribute to the cooler-than-normal air temperatures.
I should also note that the Pole is not yet gaining heat, despite 24-hour-a-day sunshine. All the sunshine does reduce the amount of heat draining away to outer space, but it is not until June that the sun gets high enough to actually reverse the energy equation. The reason it gets milder at the Pole this time of year is because there is a constant importing of milder air from the south, and such air is cooled, but not as swiftly as it is cooled when there is no sun in the sky in the deep dark of December.
For the record, I’ll catch up on the surface maps. (You’ll have to forgive me for missing many; it is not the most thrilling time of year up there, especially as the lagged effects of the weak La Nina seems to have reduced the clash of temperatures between the tropics and the Poles, and there are not the blasting gales there were last year.)
When we last were watching a more typical Beaufort high had formed, displacing the more anomalous “Ralph” at the Pole. There likely was a lot of crunching and crashing of sea-ice as the atypical counter-clockwise flow reverted to the clockwise flow of the Beaufort Gyre. The most obvious manifestation was the appearance of a polynya on the east (Alaskan) side of Bering Strait. However the high was positioned more off shore and to the west of last year’s, which often brought north winds to the delta of the Mackenzie River, and kept much of a polynya from forming at the west entrance to the Northwest passage.
Even though the Beaufort High dominated the map, Ralph “signature” could be seen as a hook of milder air up to the Pole.
(Missing maps) I assume the Beaufort High is likely to persist at this time of year because the vast area of white snow formed by the Arctic Sea is conducive to cooling an air mass and causing it to sink. But it pulled enough milder air up through Bering Strait to be the author of its own demise, and allow Ralph a last hurrah of sorts. Winds at the Barneo blue-ice jetport seemed far lighter than last year. Also temperatures were reported that were often ten degrees colder than these maps show.
(Missing maps) Here we see Ralph revived.
(Missing maps) As the Beaufort High reforms I’ll be watching to see what sort of polynya forms at the west entrance to the Northwest Passage. Also it is to be noted that some of the world’s biggest rivers flow into the arctic, and though their flows are frozen to a trickle in the dead of winter, starting around now their flow starts to swell with the spring melt occurring upstream, to the south. The pulses of fresh water into the Arctic Sea creates “lenses” on top of the saltier water, which initially are swift to freeze, but get warmer as time passes. Especially interesting is the Mackenzie Delta in Canada and the Lena Delta in the Laptev Sea.
Is Ralph attempting to sneak back into the picture?
Of course no report would be complete without the ubiquitous “extent” graph, which at this point shows sea-ice outside of the Arctic Sea vanishing. In the Arctic there has actually been an increase in Barents Sea, with ice pushed south around Svalbard, even as the polynya has reduced the extent in Bering Strait.
The edge of the sea-ice in Barents Sea tends to mess with your mind at times, and is one reason the “extent graph” needs to be taken with a grain of salt. It seems obvious that the edge will retreat north in warmer weather, but the ice-edge has behaved in a counter-intuitive manner in the past, coming south in the summer (four summers ago?) It also can retreat north during the coldest darkest days of January, as it did last January when Ralph sucked north a strong surge of moist air. As I recall many looked at the ice-edge at that time and, like a rube counting his chips at a poker table, assumed there would be more open water in May. Not so. (January to left; May to right).
Besides the Polynya on the Alaskan coast of Bering Strait, there’s an interesting one in the northwest of Hudson Bay, with the ice piled very thickly just south of it. Newfoundland is also in the news, with a great many large bergs reported, (though I always wonder: If a big berg breaks into twenty pieces, are the numbers inflated?)
It will be a while before it really warms up. O-buoy 14 shows the diurnal swing at 74° north latitude, with the solar power shutting down during the dark times. You can see evidence of BHI (Buoy Heat Islands) that will eventually have the buoy in its own private pool, but temperatures are still getting down below -20°C (which never makes the DMI maps.)
What impresses me most is how quickly the sun gets higher…
….and how quickly the nights get shorter.
Barrow, Alaska, at latitude 71.3°, has been by the Beaufort High, and I’ve been watching to see of any southeast winds might rip the ice from the shore, but I’ve been surprised by how often the winds disobey the isobars. Perhaps the flow is out from the center of the high, for often their winds have been inshore, from the north. Currently they have north winds at 10 mph, light snow, and a temperature of 14°F. (-10°C).
To its north, on April 30, Buoy 2017A was at 73.66° N, 153.21° W, reporting -16.5° C, and the ice was getting thicker.
Up by the North Pole 2017B is drifting slowly towards Fram Strait, and reporting -17.7°C, and, if not thicker, its ice is not melting.
In other words, though the “extent graph” shows the amount of ice decreasing, the real melt hasn’t started yet.