“Ralph” (Anomalous polar low pressure), which was created by a North Atlantic gale that swerved left and proceeded north right up the spine of Greenland, has merrily crossed the Pole and headed towards Central Siberia. On November 17th new low bombed-out south of Greenland, as high pressure was pumped over West Siberia.
As Ralph passes the Pole he sucks north milder Atlantic Air, creating a “signature hook” in the temperature isotherms.
Twelve hours later we see Ralph moving closer to Siberia, and the high pressure in his wake to some degree cutting off the Atlantic “feeder band”, and redirecting it north of Greenland where “Ralph Junior” is brewing. Major cold is building in Central Siberia, and the North Atlantic Gale is not moving north into Baffins Bay like the last one.
The “signature hook” can still be seen in the temperature isotherms, but cooling is evident. A slight hook is appearing north of Greenland.
Twelve hours later Ralph has reached the New Siberian Islands, as Ralph Junior develops north of Greenland. The North Atlantic gale is wobbling east towards a more traditional stance as the Icelandic Low.
The temperature map reveals only faint traces of Ralph’s original “hook”. The temperature isotherms reveal both the minus-five and minus-ten isotherm have retreated west along the Siberian coast towards the North Atlantic. Not that the mild air has moved west; rather it has physically cooled. A less dramatic hook of Atlantic air is probing north of Greenland to feed Ralph Junior. Interesting to me is the elongated pocket of minus fifteen isotherms extending from the Canadian Archipelago and crossing the Pole. Did the primary Ralph leave colder temperatures in its wake?
Twelve hours later this morning’s map shows the primary Ralph is fading on the coast of Siberia, cut off from its feeder band. Ralph Junior is surviving north of Greenland, but the Icelandic low looks like it is sweeping in a lot of North Atlantic “juice” and perhaps cutting off Ralph Junior from further supplies.
The temperature map shows little trace of all the warm air the original Ralph brought north, and the original “hook” has vanished. The secondary hook made by Ralph Junior imports fresh mildness over the Pole (if you can call minus-ten Celsius “mild”).
Importing all the mild Atlantic air north has created a dramatic spike in the DMI polar temperatures graph, now starting to descend.
While this spike is incorporated into global-average-temperatures, and makes them look higher, to me it appears it is largely a reflection of heat lost. If you desire to retain heat it should be placed in the piggy-bank of the south, not squandered under the sunless skies of the north.
When I look a little deeper I notice an oddity. Initially the surge of Atlantic air made the entire Arctic Ocean “white hot” on the GFS temperature anomaly-map (from Weatherbell). (“White hot” is still below freezing, but 16 to 30 degrees above normal.) However Ralph’s transit of the arctic did not increase or even sustain that anomaly. In fact the “white hot” area appears cut in two, as if Ralph left a trail of cooling in his wake. (Also Ralph Junior involves some less-than-white-hot temperatures in his signature curl.)
In conclusion, the overturning of the atmosphere and heat-exchanges, seen in Ralph, makes mincemeat of the ideas within the elegant idea of there being a Polar Cell of descending air and high pressure at the Pole.
One exercise I find interesting is to attempt to draw a picture of the overturning atmosphere as elegant as the above one is, but to include a Ralph of rising air. Try it. All sorts of problems manifest.
One fascinating thing to observe has been a reverse from a cross-polar-flow to a cross-polar-low. The flow was from Europe to Canada, and in barely a week this swung to a whirl from Greenland to Siberia. I don’t claim to understand what I watch, but I think it is well worth watching. Geeks (not me) who devote study to such stuff deserve funding, for, rather than a mere reflection of what happens at more southerly latitudes, these arctic shenanigans may be pivots that swing the weather further south. The discovery of a forecasting “tool”, as valuable as the discovery of the tropic’s “MJO” was, may be awaiting discovery.
Sorry to be so distracted from sea-ice by what is moving and shifting and growing the sea-ice. The sea-ice itself is continuing its ordinary expansion, and so far we haven’t seen the down-dip which sometimes occurs in late Autumn, despite Ralph bashing the ice about a bit.
The appearance of Ralph north of Greenland did bring about wrong-way south-winds in Fram Strait, slowing and even briefly reversing the discharge of sea-ice south into the Atlantic down the east coast of Greenland, and also compressing that sea-ice against Greenland’s coast. This reduces the possibility we’ll see the rarity of an ice-bridge between Greenland and Iceland in early January.
The area of open water north of Bering Strait is shrinking but still sizable. Beaufort Sea is nearly completely frozen, the retreat on the Kara-Sea-front has reverted to expansion, the top of Baffin Bay is seeing rapid expansion of sea-ice despite the recent south winds, and Hudson Bay is starting to freeze (which is always interesting to watch.)