Tuesday, 1 May 2018

Major Arctic Warming Event coming

Major Arctic Warming Event Predicted For the Coming Week

30 April, 2018

It’s been consistently, abnormally, warm in the Arctic for about as long as any of us can remember. But during recent years, the changes — caused by a massive and ongoing accumulation of heat-trapping gasses in the Earth’s atmosphere — appear to be speeding up.
(Far above normal temperatures are expected to invade the Arctic this week. The likely result will be an acceleration of sea ice melt and retreat. Image source: Global and Regional Climate Anomalies.)

This week, two major warm air invasions — one issuing from Siberia and another rising up through the Fram Strait and extending north of Greenland are expected to bring locally 10-20 C above normal temperatures and accelerate early season sea ice melt in an already reeling Arctic.
Consistent Warmth, Record Low Sea Ice

The farthest north region of our world has just come out of a winter during which sea ice extents consistently entered never before seen daily low ranges. With the advent of spring, sea ice measures have rebounded somewhat from winter record lows. However, according to Japan’s Polar Research Division, we are presently experiencing the second lowest daily sea ice extents since consistent measurements began. Meanwhile, Greenland during April saw an odd early bump in surface melt.

Overall, the pattern has been one of consistent abnormal warmth. And over the coming week, a number of warm air invasions will infringe upon the typically cold early May Arctic — testing new boundaries yet again.
(An ice-free Bering Sea, open water invading the Chukchi, and fractured sea ice over the Beaufort are notable features for melt season start during May of 2018. Image source: NASA.)

Much of the heating action this year has occurred over the Bering and Chukchi seas — which have never seen so much ice lost. Already sea ice is greatly reduced through these regions. Open water extends far into the Chukchi — onward and north of Barrow, Alaska. Still further into regions in which sea ice is typically rock-solid during this time of year, the Beaufort is experiencing its own late April break-up. But the areas that are expected to see the greatest warming over the coming days run closer to Siberia and the Atlantic.
Major Spring Warm Air Invasion

Today, a wedge of above-freezing air is invading the Laptev Sea north of Central Siberia. Strong southerly winds issuing from Central Asia are running north into the Arctic Ocean. They bring with them 10 to 20 C above average temperatures for this time of year — which is enough to push readings as high as 35 degrees F (2 C) over what during the 20th Century would have been a solid fringe of the polar ice cap.

Over the next 24 hours, this leading edge of warm air will spiral on toward the East Siberian Sea — bringing above freezing temperatures and liquid precipitation with it.
(5-Day forecast maximum temperatures show considerable warm air invasions proceeding throughout the Arctic. In many cases, temperatures near the North Pole will be warmer than regions far to the south. An impact of the warming world ocean on the Arctic environment. Image source: Climate Reanalyzer.)

But the main warming event for the Arctic this week will occur in the region of the Fram Strait east of Greenland. A strong low pressure system near Iceland is expected to drive wave after wave of much warmer than normal air north into the Arctic. This warm air thrust will bring with it temperatures in some places that exceed 20 C above average. Overall, Arctic Ocean basin temperatures are expected to average more than 2.3 C warmer than normal for the entire first week of May. Such high temperature departures are particularly notable for this time of year — as Arctic thermal variance tends to moderate during spring and summer.

The system will push above freezing temperatures deep into the Arctic — generating a repeat of the strange flip-flop that has become so common recently where temperatures near the North Pole are much warmer than readings further south. Warmer than freezing temperatures will also over-ride coastal portions of northeastern Greenland in yet another odd aspect of the event.
Warm storm effects including gale force winds and waves of 8-12 feet will provide added effect to above freezing temperatures in impacting the sea ice throughout the Fram Strait and northeast Greenland region. Increased insolation due to sunlight spreading over the region will also add to the overall potential for melt.


No comments:

Post a Comment