Arctic Sea Ice

Iced lightning

From a children's book:

"In The Legend of Lightning and Thunder, a traditional legend that has been told in the Kivalliq region of Nunavut for centuries, two siblings resort to stealing from their fellow villagers, and inadvertently introduce lightning and thunder into the world. This beautifully illustrated traditional legend weaves together elements of an origin story and a traditional cautionary tale, giving young readers an accessible window into centuries-old Inuit mythology that is specific to the Kivalliq region of Nunavut."

In the Arctic, the harbinger of climate change, anthropogenic global warming is causing another natural phenomenon to occur more frequently (besides coastal erosion, permafrost degradation, wild fires, etc), especially along the northern coasts. In the past, sea water would keep air temperatures too cool for thunderstorms to develop, but this is obviously changing.

Below are excerpts from a blog post by blogger/commenter Apocalypse4Real (who keeps a close eye on methane readings in the Arctic):

Iced Lightning - Lightning Strikes at 80 North

On July 8 and 9, 2016 the National Weather Service published special weather statements regarding the potential for thunderstorms in Barrow, Alaska and on the North Slope. There was not a thunderstorm reported in the media, although on July 10, 2016 there was a cloud to ground strike 15 miles from Barrow.

Curious, I decided to research the background of Arctic Coast or Arctic Ocean thunderstorms, starting with Barrow and Wainwright, Alaska.

Here's what I found, and what came at the end made my jaw drop in regard to lightning strikes and thunderstorms over the Arctic Sea Ice - and the massive changes in the last 16 years of increasing thunderstorm activity over the Arctic Ocean.

Arm's race (and a storm)

As I write this, a storm is battering the ice pack on the Pacific side of the Arctic. It's not as huge as the Great Arctic Cyclone of 2012, but it's pretty decent as far as cyclones go, and it's doing its thing in that part of the Arctic where the ice pack looks weakest, but was strongest at the start of the melting season.The timing of this event is perfect for discussing one of the most important aspects of this melting season.

The image on the top right shows the ice age distribution at the start of the melting season, red being the oldest multi-year ice at that time. Due to a very intense high pressure area over the Beaufort Sea at the end of the freezing season, heavy winds drove the ice pack apart there (a so-called cracking event), causing this multi-year ice to become interspersed with very thin ice. That's the dark blue spots between all the red.

During the very first phase of the melting season the Beaufort Sea region witnessed a heat wave causing a lot of this thin ice to melt out. Because the ice pack wasn't pushed back together again, many of the multi-year ice floes were surrounded by warming waters, and ever larger holes within the ice pack on the Pacific side of the Arctic started to form. The animation below shows what happened between week 27 and week 32, or June 29th to August 9th:

Just towards the end of the animation the holes are showing up. Unfortunately these maps aren't updated until the minimum has hit, but we can still get an idea of what happened after August 9th by checking out the sea ice concentration maps provided by the University of Bremen. The following animation shows how the holes separate a so-called 'arm' of multi-year ice from the rest of the ice pack:

Open Thread February 2013

The previous open thread has gotten full enough, so here's a new one.
We might want to kick off with this animation made by commenter A-Team:

His comment:

Don't miss this -- it's happening right now, by the hour -- so head on over to 80N 150W. A huge fracture has been opening a bit east of Barrow, Alaska the last few days and it's really accelerating. The AVHRR images come up every few hours as the satellite comes over -- but they're not archived so you have to "be there" to catch them. I attached a still of the key region with a few land features labelled and an approximate distance scale as the animations is intended primarily to illustrate pack ice motion.

The imagery motions agree quite well with the Navy HYCOM ice speed and drift animation. That predicts five days out and so gives some indication of what to expect. I just attached a still for today. All the ice is moving the same way, clockwise in the Beaufort Gyre. It is just that the ice southeast of the lead just can't keep up. The ice no longer has the mechanical strength that it once did and so is fracturing under extensional tension.

Thanks for keeping an eye on this, A-Team!

Arctic storm part 1: in progress

This is what I meant when I said 'flash melting' yesterday:

Now it's there on the Uni Bremen sea ice concentration map, the next day, poof, it's gone. Mind you, not all of it is gone, the sensor is thrown off a bit due to that crazy cyclone downstairs, but it ain't exactly good for the ice if you catch my drift.

Here's the culprit:

NSIDC Arctic sea ice news June 2012

The NSIDC has released its latest analysis for the month of June.
Here are what I find the most interesting excerpts:

The last three Junes (2010-2012) are the three lowest in the satellite record. June 2012 ice extent was 140,000 square kilometers (54,000 square miles) above the 2010 record low.

(...)

The ice extent recorded for 30 June 2012 of 9.59 million square kilometers (3.70 million square miles) would not normally be expected until July 21, based on 1979-2000 averages. This puts extent decline three weeks ahead of schedule.

Barrow Break-up 4

This is the final blog post on the 2011 Sea Ice Break-up Forecast for Barrow, Alaska, as it seems that break-up has occurred on July 3rd. Paolo was very quick to raise questions two days ago.

From the official Barrow Break-up website of the Sea Ice Group of the Geophysical Institute at the University of Alaska Fairbanks:

 
2011 break-up has occurred. Break-up at UIC-NARL occurred probably around 3 July 2011 (date to be confirmed). Early melt pond development along the Chukchi Sea coast and a large sediment load of the ice may have contributed to the timing of disintegration of the landfast ice this year. Few bits of ice were left drifting along the Barrow coast to the South on 4 July. While the near-shore section of landfast ice at UIC-NARL was gone by 4 July, a substantial amount of grounded ice persisted 1 mile offshore. Also, grounded pressure ridges that formed at UIC-NARL close to the shore during the February ice shove were still in place on 4 July.

I believe this is the earliest recorded break-up, apart from the years when no significantly grounded pressure ridges formed (2002, 2003, 2004, 2007):

Barrow Break-up 3

This blog post was preceded by Barrow Break-up 1 and Barrow Break-up 2 (both containing more general info).

The Sea Ice Group of the Geophysical Institute at the University of Alaska Fairbanks has been issuing break-up forecasts for almost three weeks now. Their current forecast is for the grounded ridges approximately 5 miles off the coast of Barrow to give way on July 9th. They have been making precise forecasts since a couple of days, as break-up can be forecast no more than 16 days in advance.

Their forecast is based on the mean shortwave flux, or in other words how much energy from the sun reaches the surfaces (in W/m2). Confused and silly as I am, I had called this 'solar flux', which I believe is something else entirely.

Here is their graph:

Lots of insolation when the forecast was first made, but since then Barrow seems to have clouded over. Nevertheless, we have seen the sea ice between the ice ridges and the coast continue to melt on the Barrow webcam.

I have again retrieved images from this archive (2006 and 2007 are still images from these time-lapse videos) to compare them with this year's image on June 22nd (click for a larger vision):

Barrow Break-up 2

This is a follow-up to the first installment on the breaking up of the landfast ice on the shores of Barrow, Alaska.

Each year a few kilometres of fast ice gets stuck to the coast off of Barrow. The Sea Ice Group of the Geophysical Institute at the University of Alaska Fairbanks tries to predict when this fast ice will start to break up. In typical years, the timing of break-up is associated with the amount of incoming solar energy, and so they use solar flux data to determine when the fast ice will start to break up and the coast is cleared. This graph from the 2010 Sea Ice Break-Up Forecast webpage shows the relationship between solar flux and break-up in previous years:

One important factor for the forecast is the formation of grounded pressure ridges. These ridges are formed when the ice converges towards the coast, gets pushed together, ice floes flip and get stuck in the sea floor of the shallow waters off the coast of Alaska:

Barrow Break-up 1

This is a quick and dirty blog post to be used as a reference later on. Yesterday I remarked in the comment section of the last SIE update that I saw some melt puddles starting to form on the ice that can be seen on the webcam in Barrow, Alaska (see map to the right where that is). Each year a few kilometres of fast ice gets stuck to the coast. The Sea Ice Group of the Geophysical Institute at the University of Alaska Fairbanks tries to predict when this fast ice  will start to break up.

They have a great website and I can highly recommend reading their forecast page for last year that has a lot of info on what it is they do exactly. They also have a webpage that is filled to the brim with graphs that are monitoring all kinds of current conditions (temperature, thickness, relative humidity, etc). And last but not least, the thing that has inspired this blog post, they have a webcam in downtown Barrow that is updated every five minutes. Lodger offered a link to an archive of these images that I'll use for a next blog post that compares webcam images from 2008 to the present day.

Here's a good image that shows the first melt puddles:

This isn't the place where they are monitoring break-up conditions, by the way. They do this a bit further north at the Navy Arctic Research Laboratory (NARL):