“Freedom’s Just Another Word for Nothing Left to Lose.” (Kris Kristofferson)

In April, Arctic ice extent is declining as usual with the notable exception of Bering Sea, along with ice retreating in nearby Okhotsk.  Bering still has some ice to lose, but at 178k km2 it is only 31% of the ice there January 27, the largest Bering extent this year.  It is unusual since the Bering ice is only 25% of the 12 year average for this date.  Nearby Chukchi Sea is hardly showing any open water, down only 10k km2 from its maximum.  Open water is also gaining in Okhotsk, the other Pacific basin, but ice extent there is still 6% above the 12-year average.

Elsewhere things are mostly typical with Russian and Canadian basins still frozen with high extents.  The other two places losing ice are Barents and Baffin Bay/Gulf of St. Lawrence shown below.
On the right side is Barents losing ice along the Russian coastline, while holding onto Svalbard.  On the left, water in Baffin Bay is pushing north along the western Greenland coast.  On the extreme left is open water taking over in Gulf of St. Lawrence

The graph below shows how the Arctic extent has faired since the March maximum compared to the 12 year average with and without the Pacific basins of Bering and Okhotsk.  The green line is the 12yr. average without B&O, while 2019 appears in purple when Bering and Okhotsk are excluded.
As of day 105, 2019 ice extent is 858k km2 below the 12yr. average, a gap of 6%.  529k km2 of that difference comes from the combined losses in Bering and Okhotsk.

The graph below shows March/April 2019 compared to average and some years of interest.

All years are tracking below the 12-year average.  2019 MASIE and SII are the same and well below 2018, largely due to Pacific ice losses. 2007 is only slightly higher than 2019 at this point.  The table below shows ice extents by regions comparing 2019 with 12-year average (2007 to 2018 inclusive) and 2007.

Of course both of these basins will melt out long before the September minimum, along with the Russian shelf seas.

As indicated earlier, Bering supplies almost 2/3 of the deficit to average, with Baffin Bay providing most of the other 1/3. Of course both of these basins will melt out long before the September minimum, along with the Russian shelf seas.

The monthly average for March represents the annual maximum for Arctic ice extent.  The graph shows the 12-year March average in MASIE is 15M km2, with SII about 200k km2 less.  In this period six years were higher and seven lower, including a virtual tie between 2019, 2015 and 2007, slightly higher than 2017 and 2018.  In either MASIE or SII this March is ~330k km2 or 2% below the 12-year average.

As we will see, March 2019 ended with a flash melt that reduced extents dramatically in the final week or so.  First the graph of March comparing the daily extents.

Note that 2019 was close to average as recently as day 79 before dropping well below average and recent years.  As reported previously, most of the decline was due to early melting in Bering Sea, which loses its ice every Spring anyway. Below compares NH ice extents with and without Bering ice.

The gap between the black and green lines shows Bering contributed on average ~600k km2 to overall NH ice extents at the beginning of February, increasing to 800k km2 by end of March.  In 2019, the gap between the cyan and purple lines shows ~500k km2 of Bering Ice starting in February, decreasing to 140k km2 by March, then increasing up to 450k km2, and now back down to 180k km2. When the Bering volatility is set aside, the purple and green lines show Arctic ice excluding Bering was above average most of the month, and only slightly lower at the end.

So what has been happening?  In two words: Polar Vortex.  When cold Arctic air descends into parts of North America and Euarasia, warm moist air intrudes into the Arctic to replace it, and ice extents are reduced. For example, see the recently reported balmy weather in UK, and soon to be switched to bitter cold weather. From the Express  UK weather forecast: SHOCK Map shows Britain ENGULFED by freezing Arctic weather front

The cold front is shown in the image, The link underneath goes to the video.

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The table below shows extents for day 90 comparing 2019 to the 12 year average, and also showing the 600k km2 loss of ice in just 8 days at month end.

Note that BCE (Beaufort, Chukchi and East Siberian) is rock solid, along with Laptev.  Atlantic melting has begun, with the largest losses in Barents and Baffin Bay.  The major deficit in Bering is there, And while Okhotsk has started melting, it remains 235k km2 above average at this time.

In February the media breathlessly told us that Bering Sea ice has melted away, and thus Arctic ice is doomed.  Now we see that reports of the demise were premature.  More surprising than the early retreat, Bering ice roared back in the last two weeks, and continues to grow even after the overall NH ice extent peaked

Two Weeks of Growing Bering Ice: The above image shows the last two weeks of dramatic ice growth in Bering with only minor melting in Okhotsk. Bering Sea on the right more than doubled, adding 250k km2 and effectively sealing off Chukchi inside the Arctic.  Meanwhile on the left Okhotsk ice seesawed, ending up 150k km2 lower, but still at 88% of 2019 maximum.
The graph below shows March progress in ice extent peaking and beginning the melt season. As noted before, the month started with a sharp increase nearly reaching average and 15M km2. After March 12, ice declined steadily as is normal after mid-March.  2019 extent is running lower than the 12 year average, but slightly higher than other recent years.  SII is showing about 100k km2 less ice than MASIE.

The table below shows the distribution of ice in the various Arctic basins.

The table shows how 2019 is 290k km2 or 2% below the 12-year average.  Most basins are matching average extent, including Barents Sea edging slightly ahead of average.  Greenland Sea and Baffin Bay are below average. Despite recent gains, Bering ice is 327k km2 in deficit to average, nearly the difference in overall NH extent.  Meanwhile Okhotsk is 217k km2 surplus to average, partially offsetting Bering.

Above are ice charts from AARI, St. Petersburg for the annual maximum weeks in Mid-March, 2008 to 2019 inclusive. The brown color signifies Old Ice that survived at least one summer’s melt season.  The Arctic heart is beating clear and strong. Note differences between diminished years like 2012 and 2013 compared to more robust recent years.

For context, note that the average daily maximum has been ~15M, so on average the extent shrinks to 30% of the March daily high before growing back the following winter.

A previous post discussed 15M km2 as the average maximum threshold for March arctic ice extents.The graph shows 2019 exceeded the previous two years, but now it appears to fall just short.  On day 61, March 2, 2016 peaked well above 15M, and did not reach that level again. The graph shows 2017 peaked early and then descended into the Spring melt.  2018 started much lower, gained steadily before peaking on day 74, 250k km2 below average. 2019 has been exceptional, surging early to surpass average on day 54, then declined for a week, before re-surging to virtually tie the average extent on day 70.  Day 71 extent matched the earlier peak, then retreated and is now unlikely to go higher after day 75.

Presently, on day 75 2019 is 1% below the 12 year average (2007 to 2018 inclusive) and slightly higher than the preceding three years.

As reported previously, the action is mostly in the Pacific basins.  The last 10 days show Bering on the right recovering from its minimum to add back 230k km2.  Meanwhile Okhotsk on the left lost 120k km2, so the combined gain was not enough for NH to reach the threshold.  On the Atlantic side, ice extents held firm, with Barents higher than in recent years.

Note on the left the ice has pushed well south of Newfoundland.  On the right Barents ice is holding onto Svalbard, and Kara remains at its maximum.

The table below shows the distribution of ice over the various Arctic basins compared to average and to last year.

The table shows that except for Bering, Arctic ice extents are firm almost everywhere.  Barents, Kara and Okhotsk are well above average, but not enough to offset the deficit of Bering ice, even with the recent recovery.

Typically, Arctic ice extent loses 67 to 70% of the March maximum by mid September, before recovering the ice in building toward the next March.

Drift ice in Okhotsk Sea at sunrise.

For ice extent in the Arctic, the bar is set at 15M km2. The average in the last 12 years occurs on day 62 at 15.07M before descending. Most years are able to clear 15M, but in the five previous years only 2014 and 2016 ice extents cleared the bar at 15M km2; the others came up short.

On day 61, March 2, 2016 peaked well above 15M, and did not reach that level again. The graph shows 2017 peaked early and then descended into the Spring melt.  2018 started much lower, gained steadily before peaking on day 74, 250k km2 below average. 2019 has been exceptional, surging early to surpass average on day 54, then declined for a week, before re-surging to virtually tie the average extent on day 70.  One final push in the next few days could go over the top.

As reported previously, Bering Sea is a big part of the story this year.  The graph above shows NH ice extents from mid-February to mid-March with and without Bering ice.  The gap between black and green lines shows that Bering contributed about 700k km2 to the NH average, increasing to 800k km2 by the end of this period.  However, 2019 started with about 500k km2 from Bering.  The gap between the cyan and purple lines shows Bering ice declined down to 140k km2, before adding back 100k km2 in the last 3 days. Meanwhile, Okhotsk Sea next door gained steadily and is now holding above average ice extents.  Except for Bering, 2019 ice extents are well above the 12 year average (2007 to 2018 inclusive).

Typically, Arctic ice extent loses 67 to 70% of the March maximum by mid September, before recovering the ice in building toward the next March.

What will the ice do this year?  Where will 2019 rank in the annual Arctic Ice High Jump competition?

Drift ice in Okhotsk Sea at sunrise.