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Messages - Brigantine

Pages: [1] 2 3
1
Arctic sea ice / Re: NSIDC 2019 Arctic SIE September average: August poll
« on: September 27, 2019, 02:10:13 AM »
How are things looking for the September average now with just a few days to go? Which bin is it heading for?

2
Arctic sea ice / Re: September predictions challenge 2019
« on: August 29, 2019, 02:15:57 AM »
Anyone else feeling bemused that their June prediction is looking a lot better than their August one right now?
I'm feeling you there! But if my August one is out by 1 bin, I'll still be happy.
Happy I didn't pick very high confidence ;)

JAXA under 4.00 is still touch and go, but NSIDC under 4.25 is starting to look distant.

Looking at each of our predictions, it seems we think very alike!

Hypothetical scoring:
Only included contestants scoring over 20 or in the top 3 in the particular or adjacent bin.
I wanted to put this in a spoiler box, but that didn't work so I did this.

JAXA 4.30, NSIDC 4.76: jplotinus 4, Slow Wing 2, Stephan 0, Paddy -2
JAXA 4.26, NSIDC 4.60: Stephan 12, Paddy 5, SW 5, gerontocrat 4, jdallen 4, jplotinus 4, Brigantine 2
JAXA 4.10, NSIDC 4.51: Stephan 24, gc 12, jda 12, Paddy 12, Brig 12, SW 10
JAXA 4.10, NSIDC 4.40: Stephan 36, gc 20, jda 20, Brig 20, Paddy 18, Richard Rathbone 18, SW 16, Steven 13, Aluminium 2, Juan C. Garcia 0
JAXA 3.99, NSIDC 4.40: Stephan 36, Aluminium 30, JCG 30, Brig 28, Paddy 24, gc 24, jda 24, RR 23, Steven 20, SW 19, oren 16
JAXA 3.90, NSIDC 4.24: Al 38, JCG 36, Stephan 36, Brig 30, Paddy 26, Steven 26, gc 24, jda 24, RR 24, oren 20, SW 20, Neven 19
JAXA 3.74, NSIDC 4.10: JCG 40, Al 38, oren 28, Steven 28, Brig 28, Paddy 24, RR 24, Neven 24, Stephan 24, gc 20, jda 20, SW 20
JAXA 3.70, NSIDC 3.99: Al 36, Neven 26, oren 26, Steven 26, Brig 23, Paddy 21, JCG 20, RR 20, SW 18, gc 12, jda 12, Stephan 12

3
Arctic sea ice / Re: September predictions challenge 2019
« on: August 14, 2019, 06:25:03 AM »
June:
JAXA 3.75 - 4.25 medium confidence
NSIDC 4.25 - 4.75 medium confidence
July:
JAXA 3.50 - 4.00 high confidence
NSIDC 4.00 - 4.50 high confidence
August: (provisional)
JAXA 3.50 - 4.00 high confidence
NSIDC 3.75 - 4.25 high confidence

4
Arctic sea ice / Re: September predictions challenge 2019
« on: July 06, 2019, 11:20:19 PM »
June:
JAXA 3.75 - 4.25 medium confidence (down from 4.00 - 4.50 medium confidence last week)
NSIDC 4.25 - 4.75 medium confidence (no change)
July: (provisional)
JAXA 3.75 - 4.25 3.50 - 4.00 high confidence
NSIDC 4.25 - 4.75 4.00 - 4.50 high confidence

Need to do some more thinking about downside risks before the deadline... but here's my back of the envelope backup prediction.

5
Arctic sea ice / Re: What the Buoys are telling
« on: June 27, 2019, 12:18:39 AM »
Looking closer at active ITPs

Most recent profile from ITP103 has data from just 1 depth level (at 6m). [-1.4791 C   29.5616 PSU]
(so the profiler is stuck and the contour plot is NOT valid)
ITP104 is the same. [-1.5957 C  30.5993 PSU]
ITP 105 also. [-1.5791   30.3429] - I'm guessing these are all at freezing point for that salinity/pressure

ITP 107 just a 6m range from 230m to 236m (~-1.0C)

ITP 110 on the other hand, has data (~0.45C) between 738m and and 760m. (just the very bottom 22m of the tether).

The rest have no data for the last several months.

So there is no single ITP contour plot worth looking at  :(

Now to ARGO...
There is a float in the Chukchi, just east of Wrangel Island. (4902926)
There's a ~10m thick fresh layer at ~2.8C. Below that (only ~65m deep here) is ~-1.7C (near freezing). That was on June 23.

There was a float in the West Spitzbergen Current on June 8 (R3901621_075.nc)
The top 100m were ~4.5C, 35.04 PSU. Right off the northern west coast. It's probably stuck under ice now.

6
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: June 18, 2019, 10:03:43 PM »
Please, keep posting them!
This is the first thread I always open when I reach ASIF.

Thanks to all that make this thread so informative!
+1. This is the first place I come to as well.

7
Arctic sea ice / Re: September predictions challenge 2019
« on: June 15, 2019, 12:53:14 PM »
4.25-4.75 jaxa
4.50-5.00 nsidc
OK. But what confidence level?

Since there's still time, I'm revising my JAXA prediction:

June:
JAXA 3.75 - 4.25 medium confidence (down from 4.00 - 4.50 medium confidence last week)
NSIDC 4.25 - 4.75 medium confidence (no change)

Things progressed more than expected in the last week! (though not extent data)

8
Arctic sea ice / Re: September predictions challenge 2019
« on: June 12, 2019, 12:30:08 AM »
To enter, post guess and confidence in this thread before the closing date of the poll.

When is the deadline for June predictions in this thread?  Last year the deadline was 16 June, 23:59 UTC, is it the same this year?
For context, the polls last year closed:
JAXA: 2018-06-15 23h52m49s UTC
NSIDC: 2018-06-12 22h10m19s UTC

So basically the deadline for predictions was 24 hours after the later of the polls closed.

This year:
JAXA: 2019-06-11 18h24m20s UTC
NSIDC: 2019-06-11 19h45m19s UTC

I only posted in this thread some hours after the polls closed, but linked to predictions (including confidence level) I posted in the poll threads. Those posts were last edited on June 8. Please let my prediction qualify!  :)

9
Arctic sea ice / Re: September predictions challenge 2019
« on: June 12, 2019, 12:19:13 AM »
June 2019

JAXA: 4.00 - 4.50 medium confidence
NSIDC: 4.25 - 4.75 medium confidence

10
Arctic sea ice / Re: September Predictions Challenge
« on: June 08, 2019, 10:44:11 AM »
Everyone happy if we stick to the same rules for the sake of continuity?
+1 - The 2018 rules are good.

11
Arctic sea ice / Re: What the Buoys are telling
« on: June 06, 2019, 02:00:10 PM »
Just checked which ITPs seem to still be working... ITP103, 104, 105 and 110 all seem to have functioning profiles from today.

These are in the Beaufort and CAB West of the CAA.

Air temps range from 0.2C to 2.4C, under the ice things seem... pretty normal?

O-Buoy is still dead though. So no cameras!

Can't access ARGO float locations smh.

12
Arctic sea ice / Re: SMOS
« on: June 06, 2019, 11:51:14 AM »
That graph is exactly what I needed!

But... is the map from this date 2012 accessible somewhere too?

13
Link to last year's same poll thread :)

UPDATE: Provisionally voted for 4.25 - 4.75, medium confidence. Won't be surprised if I end up revising this down in the next few days.
Based simply on taking my JAXA choice and adding a bin or two. Not very sophisticated.

14
Link to Last year's same poll.

I just came back to ASIF after not keeping up for a few months... because poll season!

I have a lot of reading to do before I decide on a number... things like how well June anomalies correlate with September, what the ice surface is looking like this year and how it compares, etc.

UPDATE: relevant comment on the state of the ice surface, with links to relevant data. [HT Michael Hauber]
UPDATE 2: relevant comments on melt onset / momentum. [HT Neven]
And SMOS 10 year comparison [HT slow wing]

And then here's last year's predict-o-matic [HT Ned W] including confidence intervals. Adjusting for current JAXA data [HT Juan C. Garcia], 2019 minimum should be 4.02 +/- 1.26 (95% CI) based on predictive power of June 7 extent alone.

Provisionally voted for 3.75 - 4.25 atm, I'm thinking medium confidence.
Raised it to 4.00 - 4.50 after looking at that SMOS beige pixel count graph.

15
Arctic sea ice / Re: September Predictions Challenge
« on: June 06, 2019, 06:13:37 AM »
It's that time of year again!

Now where are our melt pond products, and where was 2012 in comparison?
(since 2012 extent starts dropping like a rock... now)

Is there a poll thread somewhere already? (yes: JAXA, NSIDC)

16
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: March 14, 2019, 08:57:24 PM »
Previous maxima [JAXA extent, since 2005] in million square km: [re-ordered]
2019 is now the median

1. 2017: 13.88
2. 2018: 13.89
3. 2015: 13.94
4. 2016: 13.96
5.= 2006: 14.13
5.= 2011: 14.13
7. 2007: 14.21
8. 2019 to date: 14.27
mean: 14.31
9. 2005: 14.4
10. 2014: 14.45
11. 2013: 14.52
12. 2009: 14.66
13. 2010: 14.69
14. 2012: 14.71
15. 2008: 14.77

High: Barents, St. Lawrence, Okhotsk, CAB
Low: Bering, Baffin (specifically the Subpolar Gyre, per CIS anomaly charts)

17
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: February 23, 2019, 08:18:09 AM »
Previous maximums [JAXA extent, since 2005] in million square km: [re-ordered]

1. 2017: 13.88
2. 2018: 13.89
3. 2015: 13.94
4. 2016: 13.96
5.= 2006: 14.13
5.= 2011: 14.13
2019 to date: 14.17
7. 2007: 14.21
8. 2005: 14.4
9. 2014: 14.45
10. 2013: 14.52
11. 2009: 14.66
12. 2010: 14.69
13. 2012: 14.71
14. 2008: 14.77

18
Arctic sea ice / Re: January Poll 2019: JAXA Maximum
« on: January 31, 2019, 03:55:55 AM »
14 - 14.25. Overlapping with 2/3 of the responses.

Not expecting any surprises

19
Arctic sea ice / Re: September Predictions Challenge
« on: January 31, 2019, 03:09:20 AM »
January JAXA max prediction: 14 - 14.25 Medium (assuming it's being judged as 0.125M wide bins as per the poll)

(or 14 - 14.5 High if it's being judged as 0.25M wide bins as per predictions of the minimum)

20
Arctic sea ice / Re: September Predictions Challenge
« on: January 16, 2019, 05:29:24 AM »
Let's re-open this for the January poll for the maximum...

21
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: January 04, 2019, 12:32:01 AM »
I thought I remembered a formation equivalent list, but I can't find it. Just that it is normally in "January/February".

[...] approx. breakup times, southern "arch" in Kane Basin unless noted otherwise:
[...] I should note - as can be inferred from the numbers - that the dates are somewhat rounded:

2007 - No arches formed.
2008 - June 10th(?)
2009 - No southern arch. Northern arch broke around June 30th.
2010 - July 10th
2011 - July 5th.
2012 - June 30th.
2013 - July 10th.
2014 - June 20th.
2015 - July 5th.
2016 - June 30th
2017 - No southern arch. Northern arch broke around May 10th.
2018 - June 30th.

22
Arctic sea ice / Re: Poll: year-end JAXA extent ranking
« on: January 03, 2019, 11:21:41 PM »
I guessed 12.15, (2nd or 3rd place), and the end result was 12.16.

I considerably under-estimated the Pacific ice, and considerably over-estimated the Atlantic ice. The errors cancelled each other out ;D

Happy New Year everyone!

23
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: December 19, 2018, 02:35:24 AM »
If ARGO floats suspect sea ice, they won't surface & transmit the new profile. They just save the data and transmit it next time.

Also I don't know how long the batteries will last with no sunlight.

24
Arctic sea ice / Re: The 2018/2019 freezing season
« on: December 13, 2018, 12:03:04 AM »
Per CIS, the Parry Channel is mobile again.

Also, there's this one ARGO float sitting in the warm current NE of Svaalbard (~82N 39E).
It's taking profiles every day, and it's quite Atlantified there.

25
Consequences / Re: Volcanoes
« on: November 29, 2018, 12:13:17 AM »
If it's at 1/17 Hz and no other frequencies, then I'm not at all surprised that no one felt them.

Slow Slip Earthquakes are a relatively recent discovery, 16 years ago or something. AFAIK they aren't very well understood yet. I have a feeling this 1/17 Hz Mayotte event is going to teach us a bunch of things we didn't know yet.

For now I'll just call it the Magma Flute  :P

26
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: November 23, 2018, 08:26:59 PM »
Excuse me if you consider this cherry-picking, but the extent and area growth of late seems to me extraordinary and insane especially during this out-of-control climate change we keep hearing about.  8) 8) 8) 8) 8) 8) 8) 8)

I imagine the the 1980's average to be an average of essentially 10 differently timed steep rises. The effect of averaging then takes all the steepness out of it.

On this date, maybe 5 years in the 1980's were mostly done already and thus growing slowly again, 1 was rising steeply like 2018, and 4 had not picked up the pace yet and were still low.

It would be interesting to see a plot of extent vs growth rate, with time omitted. Then we could see if the growth rate is unusual at this stage of the S curve.

Regardless of the growth rate, it's fair to interpret that the freeze is happening extraordinary early relative to the last 20 years.

27
Arctic sea ice / Re: Poll: year-end JAXA extent ranking
« on: November 22, 2018, 09:49:23 PM »
2nd or 3rd.

After checking out this post from last freezing season's thread... 2017 already had no ice in the Bering or Okhotsk, and I expect (based on pure guesswork and hunches) up to maybe 2.5 Icelands more ice in Labrador and Barents than at that point in the 2017 season, thus 12.15 i.e. 3rd.

Maybe I would change it slightly if I knew what the Gulf of St Lawrence looked like on 2017-12-31.

28
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: November 21, 2018, 10:53:33 PM »
Specific predictions are good. We like them, and it's a shame none of the doubters made a specific prediction with a number on it (other than "normal" values, and iirc someone said 75% extent on Dec 1st).

Your calibration was just a bit off this time. As if it was a 5th percentile 'highest plausible' value, rather than a 95th percentile confident prediction. This sort of calibration is what the September Prediction Challenge was about - which I very much approve of.

I'm considering making a prediction on whether / how early we'll observe mixing to 400m+ depth in the Sub-Polar Gyre in February/March. If I do make a prediction I'll probably get egg on my face too :P

29
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: November 21, 2018, 10:05:59 PM »
Not the same Hudson Bay region as used in other products - This one includes a chunk of the Labrador Sea, and excludes half of Foxe Basin.

But it's at a 25 year high for the date (same week), and by a reasonable margin.

It would have been quite impressive... but then bbr set the anchor at 75%, and there's a long way to go to get there yet  ::)

30
Arctic sea ice / Re: The 2018/2019 freezing season
« on: November 20, 2018, 10:40:21 PM »
The garlic press is now closed, according to the Russians. (but if Canada disagrees tomorrow, I'll follow them)

Svaalbard must be an eerie place at the moment - No light, (sun 6*+ below the horizon at all times) but at the same time no ice.

31
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: November 20, 2018, 07:49:46 AM »
Where is 2008? It can't be too far above 1996 right?

Other than 1996 and 2003, the years on the list are all the years since 2005 - with only 2008 missing.

32
That is liquid equivalent in snow through 240 -- 2" is normally 20-24".
Citation needed?

33
Arctic sea ice / Re: The 2018/2019 freezing season
« on: October 17, 2018, 11:23:36 PM »
And note the Mercator 10 day projection in the middle. The profile is much saltier than the profile 10 days earlier. It looks like I have found a problem with the forecast model.

It's not the model, it's just the scale. Darker colours representing the same salinities. Mercator is like that.

34
Arctic sea ice / Re: The 2018/2019 freezing season
« on: October 07, 2018, 09:22:26 PM »

Why would a weaker AMOC lead to more transport up Norway instead of Labrador?
My understanding of that:

1) Overturning happens when the surface water becomes (slightly) denser than the intermediate water beneath it
2) Weaker OC implies a water column that is less dense (particularly in the surface layer)
3) This further implies a higher sea surface height (more like a less pronounced depression in SSH)
4) Gradients in sea surface height influence ocean currents, particularly in areas where the sea bed is at ~500m depth - such as the ridges from Iceland towards the SW (along the Mid Atlantic Ridge), and to the Faroe Islands, and also the entrance to the Barents Sea and the ridge NW of Svaalbard

So all else equal a stronger OC in the Sub-Polar Gyre (S tip of Greenland) pulls more of the ex-gulf stream water in the Iceland/Faroe Islands region towards Iceland and spiraling into the SPG, instead of towards the Faroe Islands and up the Norwegian coast. Stronger OC in the area around Jan Mayen pulls more warm(ish) water into that gyre instead of into the West Spitzbergen Current and the Barents Sea.

Conversely, a weaker AMOC in both gyres allows more ex-gulf stream water into the Arctic and Barents.

Basically that ~500m deep ridge from Scotland to Iceland, and SW along the MAR, is a perfect switch that responds to small changes in water density in the deep water regions surrounding it. In deeper water, currents are perpendicular to SSH gradients like wind following isobars, but in shallow water currents can just go from high SSH to low SSH.

35
Arctic sea ice / Re: September Predictions Challenge
« on: October 07, 2018, 08:52:10 PM »
I would have stayed with my bets throughout the summer and therefore I didn't repeat them. Should I have done so?
If you had made the same entry in July and in August, you would have won!

36
Arctic sea ice / Re: September Predictions Challenge
« on: October 07, 2018, 12:38:53 PM »
Interesting that NSIDC was exactly one bin above JAXA - 0.25. So both were just 0.04 below the bin boundary.

A look at the confidence levels used by the 5 most successful participants:

28 Brigantine - 4x Medium, 2x High, maximum luck
24 Richard Rathbone - 4x High, 2x Medium, estimates drifted up 2-3 bins over time
24 EgalSust - 4x High, 2x Medium, narrowly missed out on an incredible score of 32 (if NSIDC were 0.04 higher)
22 Steven - 4x Medium, 2x High, estimates followed the predict-o-matic - up 2-3 bins in July then 1 bin back down
20 Neven - average confidence of Low-Medium (partly by accident), maximum bin accuracy.

Daniel B. and Stephan both did very well in June (10 points, called NSIDC dead accurately with High Confidence), but then didn't come back to this thread in July or August.

37
Arctic sea ice / Re: What the Buoys are telling
« on: September 27, 2018, 09:11:43 AM »
There are also some ARGO floats in the Chukchi / right at the western edge of the Beaufort.

38
Arctic sea ice / Re: September Predictions Challenge
« on: September 21, 2018, 10:24:47 PM »
It's looking very likely JAXA will be in the 4.25-4.50 range, and NSIDC will be either side of 4.75.

The rest of us are still waiting for NSIDC to make its mind up, but Neven can be scored now.

He got 6 out of 6! Jackpot. +20 points  ;D
(would have been an even higher score if he picked a confidence level in June)


I picked all the same bins as him except for June NSIDC (I picked 4.25-4.75). So I got at least 5/6 right. And I had higher confidence levels in June & for August JAXA.

If NSIDC comes in over 4.75, I get +26 points, if it comes in under, I get +28. It's more luck than skill, I swear!  :o Maybe I should quit while I'm ahead and not play in the freezing season...  :P

39
Arctic sea ice / Re: 2018 Melting Season - Predictions and Speculation
« on: September 21, 2018, 10:05:33 PM »
I haven't been following this thread, but it's almost time to score all the predictions... that will make interesting reading.

40
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: September 21, 2018, 10:02:16 PM »
I'm curious where compactness is up to right about now. What happened to that graph?
There you go:
Quite middle of the pack still. I'd been expecting it to be higher. Thanks for the recalibration  :)

CAB high, ESS low... but every year will have high regions and low regions somewhere or other.

41
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: September 21, 2018, 10:41:38 AM »
I'm curious where compactness is up to right about now. What happened to that graph?

42
7% too high
23% correct
69% too low

43
Arctic sea ice / Re: JAXA 2018 Arctic SIE September daily minimum: July Poll
« on: September 20, 2018, 11:56:15 AM »
21% too high
46% correct
33% too low

44
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: September 19, 2018, 10:32:44 AM »
Reading off the graph:

Sept 17: 4.49M
Sept 18: 4.50M

I don't know how to get the exact figures... but our 2018 minimum is in the 4.25-4.50 bin and is now into 7th place.
(below 2008's minimum)

45
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: September 09, 2018, 06:19:23 AM »
2018 is now below the 2010 minimum.

2003     5933760
2004     5683663
2006     5625046
2005     5179300
2009     5054055
2014     4884120
2013     4809288
2010     4622092
2018     4609439 [to date]
2008     4500623
2017     4472225
2011     4269199
2015     4257003
2007     4065739
2016     4017264
2012     3177455

46
It's looking pretty good for the 17 people who voted 4.25 - 4.75.

Very touch and go whether me, Neven etc. will still be rescued, or whether it stays above 4.50.

47
Arctic sea ice / Re: Arctic Image of the Day
« on: August 31, 2018, 12:35:56 AM »
Are those melt ponds? That haven't drained? (in OdenBalloon.jpg)

48
Science / Re: 2018 Mauna Loa CO2 levels
« on: August 31, 2018, 12:00:43 AM »
Recent readings at Mauna Loa have shown a slowdown in losses over the past several weeks.
The Kilauea eruption has stopped for the past several weeks.

Well, not completely stopped. There was still a lava lake in Leilani and lava entering the ocean until recently, but the lava river down to Kapoho dried up several weeks ago.

49
Arctic sea ice / Re: What the Buoys are telling
« on: August 29, 2018, 08:56:05 AM »
It still has a location reported for 2018-08-29, so it's not 1).

2) would be an interesting theory if it had been moving consistently in one direction and then just stopped... but it looks like it's last movements have been a bit back and forth in no particular direction, but over a range >> 1.4km.

So 3) seems most plausible to me, but I haven't looked at nearby weather data or anything.

One thing I found interesting, last time I looked the profiler was ~220m deep, in water 200<depth<500. Now it is at 477m in an area close to the 500m isobath. Not just the cable, but probably also the profiler itself is dragging along the sea floor.

50
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: August 29, 2018, 08:26:47 AM »
Now below the 2013 minimum.

2003     5933760
2004     5683663
2006     5625046
2005     5179300
2009     5054055
2014     4884120
2013     4809288
2018     4804103 [to date]
2010     4622092
2008     4500623
2017     4472225
2011     4269199
2015     4257003
2007     4065739
2016     4017264
2012     3177455

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