Support the Arctic Sea Ice Forum and Blog

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - kynde

Pages: [1]
1
Arctic sea ice / Re: The 2020 melting season
« on: July 28, 2020, 07:06:14 PM »
Shore structures, houses and garages provide an easy way to estimate wave heights.

For those that break yes, but from them it's hard to deduce what the wave height is offshore which what the forecasts are about and what we're also interested in. It's called shoaling.

2
Arctic sea ice / Re: The 2020 melting season
« on: July 28, 2020, 06:51:55 PM »
The height of individual waves at Barrow also exceeds 2 meters, which is more than the forecast.

Guestimating wave height offshore from the waves breaking to the shore is extremely difficult. Waves gain height when they approach shallower waters. Also the period cannot be properly seen from these images.

I'm not saying there aren't waves offshore, there has to be and a bad thing for the ice is that such fresh waves generated by the storm have short periods, just pointing out that the web cam imagery is not a very good proxy for the offshore waves.

Edit: windy shows almost 2m waves with 6s period hitting barrow and 2.6m with 7s period further north hitting the ice. That should give a proper stir.

3
Arctic sea ice / Re: The 2019 melting season
« on: August 01, 2019, 09:31:29 AM »
A friend living north of St Petersburg told me that the blueberries are ripe one month early this month .... Nobody can remember them this ready at this time.  Surely this is a natural indication of a high soil temperature. Not good for Arctic ice assuming this can be extrapolated across the edges of Laptev and Kara .

Hmm, you don't mention when exactly, but the end of July and early August is perfectly normal time for blueberries to ripen here abouts. And I know when they turned ripe near Imatra and near Hamina and it was not out of the ordinary in either location. Both cities are reasonably close to St Petersburg and at least make a case against extrapolating from said region north of St Petersburg. St Petersburg is quite far away from Eastern Siberia, local weather is perhaps in some correlation to the Barents, but not beyond it.

I live in Helsinki and am currently writing this about a 100 miles north west from St Petersburg. The blueberries weren't anomalously early, but there is hardly any of them this year. That may due to drough or bad weather during pollination. I'm not sure which it was this year, but this happens from time to time and is not exceptional either.

4
Arctic sea ice / Re: Freeform season chatter and light commentary
« on: July 31, 2019, 08:08:26 PM »
Is there any way to filter out messages based on poster and based on contained quotes?

This tworp is totally trolling and I while I certainly don't want to discriminate scientific illiteracy, I would like to skip that drivel myself.

5
Arctic sea ice / Re: The 2019 melting season
« on: July 17, 2019, 08:57:31 PM »
Given that this is the most watched thread on the forum, I have to announce that sadly my father passed away today, and so I won't be able to take care of things here for a week or so, maybe longer.

Awfully sorry to hear that. Most sincere condolences.

6
I ruled out less than 3 and abovce 4.5. Thus far I've been guessing little less than 4, but I'm thinking there's more chance to go considerably below rather than above, and more accurately I would've put my likely 95% estimate inside [3.0,4.25].

7
Since the GAC has been a topic today, I'm going to pop up a question that's been bothering me for ages.

The GAC formed over Siberia and moved over to the Arctic and intensified. As someone only slightly acquainted with tropical cyclone formation I'm curious how does that happen exactly? How does an extratropical cyclone strengthen over the arctic sea? With all the heat in the arctic going into the melting ice and SSTs as a result being quite steady and low what does it feed on? Or do they just run that much colder that some open sea having gained even a little bit of dew point is enough?

Also are there some features to look for that might favour their generation and intensification like we have with tropical cyclones?

8
3.5 - 4.0
This is a compromise between the great momentum so far and some recent years failing to quite live up to theirs.
Also I'm assuming the will be no GAC solely because the occurrence rate of them is so low although this year admittedly its possibility is higher than normal.

9
3.5 - 4.0

In spite of the high albedo potential and all the momentum, I'm guessing it'll fall short from 2012 as I'm assuming:
- odds for a GAC are still relatively low
- supposedly the weather is about to take turn to something a bit closer to normal
- the accumulated/dispersed ice in North Atlantic and even in Beaufort will delay melt and reduce albedo potential in said regions

But admittedly this year there's plenty potential still to swing in either direction.

10
I'm not an expert, but wikipedia has a decent page about it that you can read before one of the weather gurus chime in here and provides more insight.

https://en.wikipedia.org/wiki/Arctic_dipole_anomaly

11
The forum / Re: Forum authentication broken
« on: June 25, 2019, 11:04:45 PM »
This happened to me many times and the URL was clearly different over those few days, _but_ it's gone now and login works as expected. Might be a regression they downgraded or fixed.

12
The forum / Forum authentication broken
« on: June 22, 2019, 09:16:18 PM »
Some recent changes in forum softwate has changed the authentication so that my mobile is forced to log in all the time. The session id seems to have changed from cookie to PHPSESSID querystring parameter and to make matters worse it does not validate anymore after few hours of inactivity.

I used to just keep the index url without any querystring params open in one tab and I was always good to go to read the new threads after a reload. The changes is apparent since in spite of  me lurking about I do come in here daily and have done so for quite some time.

Any chance there's been an upgrade in forum software or settings?

13
Judging by model projections I'd say best guess is it will stay cold enough for centuries.

You can't really use contemporary models which are used to model present situation to make multi century projections. The temperature is heavily coupled to the assumption of ice presence, and that cannot be used to predict continued ice presence without circular reasoning. The odds of game changing forcings to manifest this century are simply too much.

It was already stated how models, while currently exhibiting our best scientific knowledge of arctic climate, are not tuned for the changes that are in the pipeline which are largely unknown. What seasonally ice free arctic and narrowing temperature difference will do to the northern hemisphere climate is largely unknown. And _that_ is happening well within century scale.

Now, just to be clear. I'm not saying one way or another about how cold it will stay up north in the years to come,  I'm just strongly opposed to using current models to project "centuries" given that we can't really claim to even know what's going to happen with the seasonally ice free arctic in the decades after. And as a result, how could the models do any better?

Your qualitative arguments about Laptev shallowness etc make a better argument.

14
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: August 07, 2018, 11:44:49 AM »
I guess in winter we will still see ice near the coast, but it will get smaller and smaller and float away a lot of times - of course depending on wind conditions etc

I think the point was that once it gets small enough to move as a whole the random(ish) distribution of winds will take it out and it will not return. That's how random walk works and that's what we see in other shorelines as well. (This obviously holds true only for the larger chunk leaning against northern Greenland and CAB, not the ice soup inside the CAB)

While it's large enough to not really move as a whole, like now, the ice can retreat away by compression and it can and will get back over and over by decompression and refreezing.


Where's the threshold for that? I have no idea and that's one of the interesting things I'm waiting to see.

15
What jdallen said and ...

As you know, (which many of these Brits and Floridians can't even comprehend, even when they stand upon actual ice... if they ever have ) ...

As someone who lives above 60N and has stood (walked, skied, skated, slept, etc) on ice more than most I can safely say that I gives you precious little insight to the inner working of the beast we're dealing with here. Seasonal ice over some sea or lakes is quite different from the perennial cap over the arctic sea. You'll do well if you pay heed to these experienced and smart Britons, Floridians, Austrians, Dutch, you name it.

16
I also think we're on the safe side of not totally collapsing this year, but to be fair for those making the lower guesses, to me it also seems clear that the year we're going to hit zero or close enough it will be an outlier, likely a favourable early season followed by a strong weather phenomenon like the GAC12 or worse, possibly something we haven't seen yet. Wasn't the collapse that the GAC12 induced, and frankly the GAC12 itself, quite unprecedented at the time, too?

In that sense betting low continuously should pay off one year, yet equally it will never be the most likely outcome making it somewhat of a wrong choice every year.

Forgive me for reiterating some of the points obvious to most and for outright being wrong on the rest :)

17
Arctic background / Re: USCGC Healy: scientific mission to the Arctic
« on: August 12, 2013, 09:48:59 PM »
Anyone know where Healy is heading?



She's been going around in circles for some time now. I'd like to see what the ice is like a little higher up.

18
Arctic sea ice / Re: The Cause of the Muted Melt of 2013
« on: August 12, 2013, 01:41:00 PM »
Shared Humanity,

I don't know where the single cell issue was being discussed, but I find that idea hard to believe.

I believe he was referring to Bill Langford presentation "Hadley Cell Expansion in Today's Climate and Paleoclimates" (April 28, 2011). I can't remember where exactly it was discussed in here, probably in ASIB (*).
Pdf here: http://www.fields.utoronto.ca/programs/scientific/10-11/biomathstat/Langford_W.pdf

I'm not making any implications here, only pointing it out. It's a fascinating(**) read and certainly warrants some attention. How big a role such a thing is playing in any one melt year is another matter.

EDIT:
(*) found it, it was in the "Second storm" post comments few weeks ago.
(**) understatement for me at least, reading that turned my stomach so bad I had to visit the toilet.

19
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: July 30, 2013, 03:26:55 PM »
Would it be difficult to whip up a concentration distribution graph from your calculations?
(where y would be relative amount of given concentration in x, perhaps barring 0% and 100% so that they won't screw up the scale)

Short term changes and shifts there could be interesting, perhaps provide some insight into what might be happening next.

I'm not sure if this has been asked already somewhere or if such a graph is already available somewhere and I just haven't stumbled onto it yet. If that's the case, sorry for the noise.

edit: forgot to say thanks for all the hard work in here, I frequent this thread more than any other "news outlet" in the net :)

20
The GAC2013?

Very exciting heads up, thanks guys.

21
Arctic sea ice / Re: Ice-free Arctic (Cryosphere Today SIA)
« on: July 18, 2013, 09:16:58 AM »
Where we end up this year should give us some hints as to what lies ahead given the reasonable freeze except for cracking and the sluggish start.

Although I'm a member of the early camp and have argued against all gompertz fits and such, I must admit that what dorlomin said is still very much a possibility. I think the MYI is done for but the coming changes in the ocean currents and layering as well as in weather patterns remain undetermined and they certainly have the capacity to swing it either way.

Pages: [1]