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Messages - Jim Hunt

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1
Arctic sea ice / Re: 2017 sea ice area and extent data
« on: Today at 01:00:29 AM »
This 'whose dick is biggest'-atmosphere and 'told you so'-anticipation is taking all the fun out of witnessing and discovering something together.

Cut. It. Out.

Hear, hear.

2
Arctic sea ice / Re: The 2017 melting season
« on: July 22, 2017, 09:17:21 PM »
JavaScript Jim.

I guess I should check my post next time!

3
Arctic sea ice / Re: The 2017 melting season
« on: July 22, 2017, 06:13:08 PM »
A view of the waves currently breaking on the shore at Utqiaġvik (Barrow as was):


4
Arctic sea ice / Re: What the Buoys are telling
« on: July 22, 2017, 01:22:23 PM »
There looks to me like a fairly large loss in the thickness of the overall fresher layer.

The fact that the buoy is moving seems like the likeliest explanation?

5
Arctic sea ice / Re: The 2017 melting season
« on: July 21, 2017, 03:54:23 PM »
I agree with 2015 and 2016, not so much with 2013, at least not on the base of a single image.


Here's a second image, showing some open holes on July 6th 2013:

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/summer-2013-images/#CAB

6
Arctic sea ice / Re: What the Buoys are telling
« on: July 21, 2017, 03:40:35 PM »
Near surface Salinity rising

You've linked to a live plot, which will change ad infinitum (or at least until the buoy bites the dust). Here's one preserved for posterity.

It looks to me as though in actual fact near surface salinity beneath ITP95 is currently decreasing?

7
Arctic sea ice / Re: The 2017 melting season
« on: July 17, 2017, 02:10:25 PM »
Charctic is broken??

It works fine for me at the moment.

8
Arctic sea ice / Re: What the Buoys are telling
« on: July 17, 2017, 12:52:54 PM »
No recent data from 2017A and 2017B - are they dead?

This year the data only seems to get processed for public consumption about once per week.

9
Arctic sea ice / Re: Northwest Passage thread
« on: July 14, 2017, 05:42:22 PM »
I might be old but I'm certainly not a fogie!

Be that as it may, depending on the wind and weather over the next few weeks it's not beyond the bounds of possibility that the small vessels currently heading in the direction of the Northwest Passage might encounter some problems by the time they reach the central section of the southern route:

http://GreatWhiteCon.info/2017/07/the-northwest-passage-in-2017/

10
Arctic sea ice / Re: Northwest Passage thread
« on: July 14, 2017, 12:47:24 PM »
Old ice feeding into Larsen Snd./Victoria Strait making it difficult to transit used to be very common in past years - ask Frankllin!

However I can't help thinking that the "old ice" in 2017 is much less substantial than in 1846?

11
Arctic sea ice / Re: Northwest Passage thread
« on: July 13, 2017, 10:15:59 PM »
That leaves Peel and especially Larsen Sound as the X factors.


On the southern route it looks as though the old ice in Larsen Sound and Victoria Strait will be the last to go:

http://GreatWhiteCon.info/resources/arctic-regional-graphs/northwest-passage/

12
Arctic sea ice / Re: The 2017 melting season
« on: July 11, 2017, 07:20:01 PM »
Also, sometimes ice simply looses some of it's thickness to bottom or top melt.


As measured by two ice mass balance buoys. 2017A at 77.04 N, 155.20 W

Air Temp: -0.8 C
Ice thickness : 79 cm
All Snow Melted
Ice Surface Melt: 21 cm
Ice Bottom Melt : 19 cm



2017B at 85.02 N, 4.91 W

Air Temp: 0.8 C
Ice thickness : 155 cm
Snow Completely Melted
Ice Surface Melt 10 cm
Ice bottom melt : 27 cm


13
Arctic sea ice / Re: What the Buoys are telling
« on: July 11, 2017, 07:06:26 PM »
Unfortunately, currently away, cannot do the profile animations, for a nice while.

In which case see below for the non animated version.

In addition here's the 2017B summary from considerably further north:

Pos: 85.02 N, 4.91 W
Air Temp: 0.8 C
Ice thickness : 155 cm
Snow Completely Melted
Ice Surface Melt 10 cm
Ice bottom melt : 27 cm

14
Arctic sea ice / Re: What the Buoys are telling
« on: July 09, 2017, 01:12:05 PM »
It is interesting that between 50 and 100cm depth 2017A seems to be freezing at -1C. This suggests that the ice there has a salinity of only 17 PSU.

See the seminal work of G F N Cox on sea ice salinity. E.g.

https://www.cambridge.org/core/journals/journal-of-glaciology/article/salinity-variations-in-sea-ice/0976B42E5B21CAE25BE26A0DD811513F/core-reader

15
Arctic sea ice / Re: Northern Sea Route thread
« on: July 03, 2017, 05:16:00 PM »
Via F.Tnioli, news from March 30th:

The 80,000 tonne-capacity Christophe de Margerie, an ice-class tanker fitted out to transport liquefied natural gas, docked in the icy port of Sabetta, with Russian President Vladimir Putin watching via live video-link.

Putin congratulated the crew and energy company officials gathered on the ship's bridge, saying: "This is a big event in the opening up of the Arctic."

The South Korean-built vessel was not picking up a cargo on its maiden voyage, but will eventually be used to transport gas from Russia's Yamal LNG plant, which is near the port.


http://www.reuters.com/article/us-novatek-lng-putin-idUSKBN1712K6




16
Arctic sea ice / Re: The 2017 melting season
« on: July 03, 2017, 03:48:04 PM »
If it can go good part of the NSR in _March_ these days, how exactly should we consider the NSR "closed" right now only because some canadians decided that's how it should be? I say, we should not.


How should we define it then? The NSRA web site seems to be working intermittently if at all at the moment:

http://nsra.ru/en/grafik_dvijeniya_po_smp/

However it seems that the 34,146 tonne Pugnax is currently en route from Sabetta to China. Does that mean the Northern Sea Route is "Open"?

17
Arctic sea ice / Re: The 2017 melting season
« on: July 03, 2017, 02:48:25 PM »
Correct. In fact, "good and strong boats" these days include ships like Timofey Guzhenko ice-breaking oil tanker (and her sister ships)


There has been discussion about "ice-breaking oil tankers" on the Northern Sea Route thread. See e.g.

http://forum.arctic-sea-ice.net/index.php/topic,854.msg101582.html#msg101582

My scepticism about LMV's "NSR Open" suggestion is based on the Canadian Ice Service's definition for the Northwest Passage, which appears to be "<= 3/10 concentration along the whole route":

http://GreatWhiteCon.info/2015/08/is-the-northwest-passage-open-yet/

18
Arctic sea ice / Re: What the Buoys are telling
« on: July 02, 2017, 01:56:16 PM »
locating that in worldview where pointer locations are diplayed in the bottom right corner. I then located the same floe pattern in sentinel playground where I don't know what the lat/lon reference in the URL refers to.


Why not cut out the middle man and simply add the decimal version of the lat/long to the URL?

http://apps.sentinel-hub.com/sentinel-playground/?lat=74.195&lng=-103.0567&zoom=13&maxcc=100&gain=0.5&time=2017-07-01

19
Arctic sea ice / Re: What the Buoys are telling
« on: July 02, 2017, 11:44:36 AM »
Do we know how the camera is gimbaled?


I don't think it is. Watch the video from ~7:50, when it melted out of its floe last summer. It looks to me as if the camera is firmly tied to the mast.

20
Arctic sea ice / Re: The 2017 melting season
« on: July 01, 2017, 05:10:34 PM »
How does 2017 look like so far?

Assuming your question is addressed to me, ERA Interim is only available at WRIT up to January 2017. See below for the "deprecated" NCEP/NCAR.

Also fascinating to see that the Northern Route is "more or less navigable" as of early July.

That's stretching things more than somewhat! It'll be quite some time before you'll be able to sail the Vilkitsky Strait unmolested by ice. Or were you thinking icebreaker assisted?

21
Arctic sea ice / Re: The 2017 melting season
« on: July 01, 2017, 03:47:51 PM »
Yes, it would be better to have a temperature average over the whole Arctic Basin than just over greater than 80 degrees N.


Such things are available, with a little work. See the Developer's Forum for example:

Mapping GeoCoded Data Sets

As SIS hints above the NCEP/NCAR reanalysis site allows you to generate custom maps and timeseries. However, prompted in part by the obvious difficulty the models are currently having in generating accurate forecasts for the "New Arctic", I've been comparing assorted reanalysis products:

http://GreatWhiteCon.info/2017/07/reanalysis-of-arctic-climate/

NCEP Reanalysis (R2) is better than NCEP-NCAR (R1) but still a first generation reanalysis. It is best to use 3rd generation reanalyses, specifically, ERA-Interim and MERRA
.

Unlike NCEP/NCAR there isn't a "near real time" option readily available for the alternative reanalyses, but hopefully getting back on topic here are some alternative interpretations of summers past:




22
Consequences / Re: Global Surface Air Temperatures
« on: June 30, 2017, 02:51:07 PM »
A new paper published in the Journal of Climate reveals that the lower part of the Earth’s atmosphere has warmed much faster since 1979 than scientists relying on satellite data had previously thought.

https://www.carbonbrief.org/major-correction-to-satellite-data-shows-140-faster-warming-since-1998

Researchers from Remote Sensing Systems (RSS), based in California, have released a substantially revised version of their lower tropospheric temperature record.

After correcting for problems caused by the decaying orbit of satellites, as well as other factors, they have produced a new record showing 36% faster warming since 1979 and nearly 140% faster (e.g. 2.4 times faster) warming since 1998. This is in comparison to the previous version 3 of the lower tropospheric temperature (TLT) data published in 2009.


23
Arctic sea ice / Re: The 2017 melting season
« on: June 30, 2017, 11:46:43 AM »
Thickness charts usually show a goodly percentage of this ice as thicker than average.

The low hanging fruit has fallen, but the rest may not be so easy. Compare "old ice" in the Parry Channel this year with last:

24
Arctic sea ice / Re: Northwest Passage thread
« on: June 30, 2017, 09:58:22 AM »
Definitely a lot of melt ponds.

The O-Buoy 14 webcam image hasn't updated yet today, but here's the view last night (UTC) from the heart of Viscount Melville Sound:

25
Arctic sea ice / Re: IJIS
« on: June 29, 2017, 12:57:29 PM »
Just to be I'm understanding it, the theory is that Windsat data clumped losses onto certain days, but not that it showed greater overall losses than AMSR2 would have.


The relevant section of the JAXA/ADS web site reads:

In principle, SIC data could have errors of 10% at most, particularly for the area of thin sea ice seen around the edge of sea-ice cover and melted sea ice seen in summer. Also, SIC along coastal lines could also have errors due to sub-pixel contamination of land cover in an instantaneous field of view of PMR data.

In general, sea-ice extent is defined as a temporal average of several days (e.g., five days) in order to eliminate calculation errors due to a lack of data (e.g., for traditional microwave sensors such as SMMR and SSM/I). However, we adopt the average of latest two days (day:N & day:N-1) to achieve rapid data release. Only for the processing of WindSat data (Oct. 4, 2011 to the present(sic!)) the data of the day before yesterday (day:N-2) is also sometimes used to fill data gaps.


I know folks get excited about century breaks, but they can easily be an artifact of the noisy data. For a recent example of the potential problems see this from Wipneus:

http://forum.arctic-sea-ice.net/index.php/topic,382.msg117687.html#msg117687

For comparison purposes my hastily modified NSIDC daily extent spreadsheet reveals 21 CBs by June 27th 2012, one of which was in January. The NSIDC 5 day averaged metric was up to 15 CBs by the 27th.

26
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: June 28, 2017, 08:40:16 AM »
Any ideas about earliest date the route has opened up?


You may wish to peruse these videos?

http://GreatWhiteCon.info/resources/arctic-regional-graphs/northern-sea-route/

27
Arctic sea ice / Re: What the Buoys are telling
« on: June 28, 2017, 08:36:47 AM »
Polarstern has spent to weeks tied up along side a floe north of Fram strait taking a wide range of measurements including light levels below the ice as meltponds grow.

2017A is apparently colocated with a WArming and irRadiance Measurement (WARM) buoy:

https://www.mbari.org/wp-content/uploads/2016/01/WARM-outline.docx

The timing or phenology of primary production in the Arctic is driven by light availability.  A thinner ice cover, with less snow and more ponded area increases the transmission of light to the upper water column, deepening the euphotic layer, and increasing the light available for photosynthesis and net primary production (NPP).

Some areas of the Arctic are now experiencing a second fall bloom initiated by storm mixing, which is more indicative of temperate ecosystems.

28
Arctic sea ice / Re: What the Buoys are telling
« on: June 28, 2017, 08:06:30 AM »
I guess I gotta go back and review more pix to see what it met up with when it drifted down the channel.


How about this one,  from September 10th?

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/winter-201617-images/#OBuoy14

29
Arctic sea ice / Re: What the Buoys are telling
« on: June 27, 2017, 10:45:27 AM »
All clear and good


For additional clarity, it is not beyond the bounds of possibility that the surface around 2017A currently resembles that image. In which case 2017A's top sounder could conceivably be measuring the surface of a melt pond instead of snow. A bit like this perhaps?

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/summer-2015-images/#IMB2015A

30
Arctic sea ice / Re: What the Buoys are telling
« on: June 27, 2017, 10:32:44 AM »
However, the change in Roll appears to be more consistent and I'm wondering if it could indicate an early sign of ice starting to melt out around #14.


Perhaps it's a sign of being the recipient of a bear hug?

Back in the early days when #14 had a family, I recall seeing this happen to nearby instruments. (RIP big yellow bucket  :'(  )


2017B has a family that includes a "big yellow bucket". AKA ITP 95

Another question came to mind: How deep does #14 sit? In other words, how deep would a melt pond have to be for #14 to float freely?


A "melt hole" would be required:


31
Arctic sea ice / Re: What the Buoys are telling
« on: June 27, 2017, 12:44:58 AM »
Teach me about what IS surface melt

This looks like surface melt to me:

32
Arctic sea ice / Re: What the Buoys are telling
« on: June 26, 2017, 08:24:20 PM »
I would say the ice has thinned about 20 cm in one week, but I doubt it is so much.

Bear in mind that the top & bottom sounders report:

Snow depth : 5 cm
Ice thickness : 111 cm

i.e. no surface melt yet, and 4 cm bottom melt over the last week.  Trying to estimate floe thickness from the thermistor readings is fraught with difficulty at this stage of proceedings.

33
Arctic sea ice / Re: The 2017 melting season
« on: June 25, 2017, 12:54:27 PM »
Cross post from the Wildfires thread. There's not much sea ice left off the Mackenzie Delta:



There is however lots of smoke.

34
Consequences / Re: Wildfires
« on: June 25, 2017, 12:47:32 PM »
Inspecting the remaining sea ice off the Mackenzie Delta this morning, I couldn't help but notice lots of smoke:

35
Arctic sea ice / Re: What the Buoys are telling
« on: June 24, 2017, 08:00:22 PM »
Not quite sure why this is called 'bottom' melt?

On June 20th the other sensors on the buoy were reporting snow depth of 11 cm and bottom melt to date of 4 cm. QED?

As SIS suggests, brine rejection means the bulk of the floe still isn't "above freezing" yet. Once we "get a profile without a minimum" the bottom melt rate will increase. Let's see what the next update reveals!

36
Arctic sea ice / Re: What the Buoys are telling
« on: June 24, 2017, 10:00:53 AM »
I would guess that this (your animated graphs) shed light to us "ASIF Lurkers" ond others on how gigantic areas of the Arctic ice just suddenly vanish when the heat eventually gets through from top or bottom.

I don't think that you'll find that the floe on which 2017A is sitting is going to "suddenly vanish" any time soon. Once the blue line has risen completely above the dotted red line is when bottom melt can begin in earnest. Melting away to nothing takes a lot longer.

37
Arctic sea ice / Re: The 2017 melting season
« on: June 21, 2017, 02:44:07 PM »
The "garlic press" started much earlier in 2017.

How do you come to that conclusion? My understanding is that the term "garlic press" refers to multi-year ice moving from the Central Arctic through the Canadian Arctic Archipelago. Your understanding would seem to be different from mine?

38
Consequences / Re: Hurricane season 2017
« on: June 19, 2017, 01:24:31 PM »
Arlene was pre-season April 20/21 but is it conventional to (unofficially?) extend the season back so that Arlene is the first tropical storm of the 2017 season?


I amended my post! There was much debate about whether Hurricane Alex should  be considered as part of the 2015 "hurricane season" or not. NHC naming goes by calendar year, so Arlene was undoubtedly the first official tropical storm of 2017 in the North Atlantic.

However, according to the NHC:

Forecasters predict a 70 percent likelihood of 11 to 17 named storms (winds of 39 mph or higher), of which 5 to 9 could become hurricanes (winds of 74 mph or higher), including 2 to 4 major hurricanes (Category 3, 4 or 5; winds of 111 mph or higher). An average season produces 12 named storms of which six become hurricanes, including three major hurricanes.

These numbers include Tropical Storm Arlene, a rare pre-season storm that formed over the eastern Atlantic in April.

39
Arctic sea ice / Re: Latest PIOMAS update (June - mid month update)
« on: June 19, 2017, 12:24:34 PM »
If I understand correctly the regional masks are supplied in the PIOMAS files and are the NSIDC regions.

According to Wipneus:

Using the regional mask from Chris I have made a daily regional volume data file

If I understand correctly, "the PIOMAS files" from PSC don't include regional masks.

40
Arctic sea ice / Re: Latest PIOMAS update (June - mid month update)
« on: June 19, 2017, 11:42:51 AM »
Do we have Chris’s 2013 regional mask in the form of a piomas grid cell color markup (first image below, from wip’s #1613)?


Not that I'm aware of. According to Chris:

Regions have been calculated by using the Cryosphere Today graphic of regions as a template


I don't think much in the way of "physical considerations for defining natural boundaries" went into defining those

41
Consequences / Re: Hurricane season 2017
« on: June 19, 2017, 11:30:05 AM »
A Tropical Storm Warning is in effect for...
* Barbados
* St. Vincent and the Grenadines
* Trinidad
* Tobago
* Grenada

42
Arctic sea ice / Re: Latest PIOMAS update (June - mid month update)
« on: June 18, 2017, 06:23:26 PM »
I updated the daily regional volume data file


Thanks Wipneus. Here's the regional graph for day 166:

http://GreatWhiteCon.info/2017/06/facts-about-the-arctic-in-june-2017/#Jun-18

43
There's no sign of it on this list though:

https://www.emsc-csem.org/Earthquake/world/M4/

44
I can find no record of a recent earthquake in the vicinity. Can anybody else?

45
Slightly belatedly, news that the Hudson Bay Railway to Churchill has been washed away:

http://globalnews.ca/news/3516324/train-to-churchill-man-suspended-indefinitely-after-flooding-damage/

The only ground transportation to Churchill on the coast of Hudson Bay in northern Manitoba has been suspended indefinitely and is not expected to resume until winter.

The owners of the Hudson Bay Railway line say flooding that submerged a section of the track and stopped service on May 23 has caused severe damage.

“A preliminary assessment … indicates that the track bed has been washed away in 19 locations. Five bridges are visibly damaged and an additional 30 bridges and 600 culverts … will need to be further assessed for structural integrity,” Omnitrax Inc. said in a news release Friday.


46
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: June 17, 2017, 06:28:51 PM »
I am unsure about the scale of impact, but the abnormality of much older/thicker floes into the Hudson (5-8m!!!

The "older/thicker floes" aren't "into the Hudson" are they? According to the CBC report:

The icebreaker was diverted from its course to help ferries and fishing boats navigate the Strait of Belle Isle. "The requirements for search and rescue trumped the requirements for science," said Barber.

Assorted journos seem to have got hold of the wrong end of the stick.

47
Arctic sea ice / Re: 2017 sea ice area and extent data
« on: June 17, 2017, 02:21:38 PM »
(I sometimes think I see the tint of blue in Worldview images, but mostly I don't get it - I presume it is due to some degree of color blindness on my part.)

Have you tried using MODIS bands 7-2-1? See for example:

https://go.nasa.gov/2tyHgL7

then compare with June 10th.

48
Consequences / Re: Hurricane season 2017
« on: June 17, 2017, 02:16:46 PM »
Two shots at the first tropical storm of the "official" 2017 Atlantic hurricane season:

49
Arctic sea ice / Re: The 2017 melting season
« on: June 17, 2017, 01:58:00 PM »
With no signs of significant melt-accelerating conditions , a record low is looking far less possible.


This looks like a sign of accelerating melt to me?

http://GreatWhiteCon.info/2017/06/facts-about-the-arctic-in-june-2017/#Jun-17

I'm afraid I place little store by DMI/Polar Portal thickness/volume. Have you seen all the extra thick ice that they reckon is currently sitting in Foxe Basin?

The late, great Andrew Slater once suggested looking at area weighted 925 hPa temperatures rather than DMI's "North Pole weighted" 2 meter temperatures:

http://forum.arctic-sea-ice.net/index.php/topic,1149.msg56878.html#msg56878

50
Arctic sea ice / Re: Latest PIOMAS update (June)
« on: June 17, 2017, 11:17:51 AM »
My own first draft of a "Chris Reynolds style" regional volume graph, based on the monthly data for May:

http://GreatWhiteCon.info/2017/06/facts-about-the-arctic-in-june-2017/#Jun-16

As Wipneus said:

No checks, but the data looks plausible.



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