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 - StopTheApocalypse

Pages: [1]
Arctic sea ice / Re: The 2017/2018 freezing season
« on: October 28, 2017, 12:38:26 AM »
I'm actually struggling to understand these forecast maps. Both precipitation and cloud cover are supposed to be forecast. It is easy to see the precipitation forecasts but I'll be damned if I can understand cloud cover here. How are you supposed to see % overcast?

Does solid white mean thick cloud cover? If so the Arctic is forecast to be solidly overcast for the entire next week.

It's incredibly frustrating that both sea ice and clouds are essentially the same color. A product with off color ice/clouds would be helpful, I think. And yes, a better color scheme with more variation for cloud cover would be useful as well.

Arctic sea ice / Re: The 2017/2018 freezing season
« on: October 26, 2017, 10:15:23 PM »
Probably on the wrong side of predictability, but GFS suggests some pretty large heat anomalies next week. This is the 168h.

Science / Re: "climate porn" vs. "not alarmed enough"
« on: July 13, 2017, 02:01:10 AM »

The comments in this article strike me as unbelievably cowardly. Scientists all admit we do not talk enough about tail risks, but if you try and do that you get shot down by scientists. The author has said he literally sent out the text of many paragraphs to experts, but the article still got a score of "low" credibility. This is profoundly disappointing.

Arctic sea ice / Re: The 2017 melting season
« on: July 11, 2017, 03:58:56 AM »
Are we sure about the reliability of any data sources?

Before we go too far down the rabbit hole, the authors of PIOMAS did verification studies, no?

Arctic sea ice / Re: The 2017 melting season
« on: July 07, 2017, 09:15:46 PM »
Per discussion of Kara ice, it's gotten noticeably darker in the past couple days. Via worldview.

Edit: needs a click now, since I couldn't figure out how to resize it and still have it play on a loop.

Arctic sea ice / Re: The 2017 melting season
« on: July 07, 2017, 12:40:21 AM »
Neven, I think you may have uploaded the wrong photo; your first image has an initialization date of June 26th =p

Arctic sea ice / Re: The 2017 melting season
« on: July 06, 2017, 08:42:36 PM »
ECMWF and GFS both point to pretty strong (I think, I'm new, so correct me if I'm wrong) dipoleish setup in 4-5 days.

Edit: Screenshot is 120hr, but it starts around 96.

Arctic sea ice / Re: The 2017 melting season
« on: June 23, 2017, 11:08:00 PM »
Latest run (12z) has low bottoming out as 975 (GFS) or 970 (ECMWF) mb. Hycom suggests this will result in large drop in concentration (and thickness) over center of basin.

Edit: err, having some trouble attaching images. Any tips? I took it straight from the hycom snapshot archive.

Edit 2: Thanks!

Arctic sea ice / Re: Latest PIOMAS update (June - mid month update)
« on: June 18, 2017, 07:35:06 PM »
A gap can disappear as quickly as it was formed.
This is very curious, as it almost makes it seem like summer and winter in the Arctic have nothing to do with each other.

Eh, the gap disappearing seems mostly due to the exceptional melt season of 2012. Seems like 2017 roughly kept pace with many other years.

Arctic sea ice / Re: The 2017 melting season
« on: June 16, 2017, 10:05:08 PM »
Let's try it again! :) BOTH GFS and ECMWF 12z op runs depicts a possible bomb cyclone by D8 ranging from 961 hpa (GFS) to 971 hpa (ECMWF). While it certainly is far away in time to make any clear conclusions it is absolutely a bad omen that both models evolve such a strong cyclone over vitually the same place and about the same i the forecast run.

I believe that the GFS run is too strong. A 961 hpa bomb cyclone in June would be somewhat lower than the GAC back in 2012 which bottomed out at about 963-964 hpa. At this stage, the ECMWF solution seems more realistic if such a cyclone is going to develop.

In any case, the upcoming forecast runs will be very, very interesting to follow!!!

Worth noting that GFS overestimated the depth of the low currently moving into the arctic; earlier runs had it bottoming out much lower than current runs. Will be interesting to watch, in any case.

Arctic sea ice / Re: IJIS
« on: June 15, 2017, 09:03:08 PM »
I expect there will eventually come a time where the number of climate change deniers will dwindle to the point where they're essentially irrelevant, like the flat earthers. I would love to think that we could reach that point earlier rather than later, maybe because some event like an ice-free North Pole some year soon would convince certain prominent voices among them to change their minds.

It's a thin hope, but I think it's behind why some part of me roots for a record low extent each year.

If it makes you feel better, this is actually the case literally everywhere besides the US. Parties that deny the reality of climate change have been continually eviscerated; UKIP was the latest example. Insofar as that reflects the views of the electorate, it does seem to indicate that most people in the world accept that climate change is happening and caused by humans.

Edit: Sorry, realized this is probably too off topic. Won't respond any further.

Arctic sea ice / Re: The 2017 melting season
« on: June 13, 2017, 01:58:56 AM »

As you can see, there are even less melt ponds than last year. In fact, it looks very similar to 2013. David Schröder wrote to me in an e-mail:

Looking at the Archipelago on MODIS today it looks very blue, is that not melt ponds?

Neven's post was based on May's data, so any melt ponding in June wouldn't be taken into account yet. Weirdly though, predictions don't become much more accurate when taking into account melt ponding in June vs only May, if I remember right.

Arctic sea ice / Re: IJIS
« on: June 09, 2017, 09:45:44 PM »
The difference between third and fifth place is so tiny that it's literally imperceptible on that graph, so I wouldn't read too much into the move from fourth to fifth.

Arctic sea ice / Re: Latest PIOMAS update (June)
« on: June 08, 2017, 06:47:01 PM »
Probably doesn't make sense to just be looking at DMI 80N temperatures though, since it only covers about half the basin and completely ignores insolation; I don't necessarily know if it's a good proxy, alone, for estimating volume loss.

Regardless of what the poll shows, I think most of us probably agree that the probability of disaster this year, given the very thin ice, is high; the probability distribution is almost certainly skewed towards bad outcomes.

Arctic sea ice / Re: 2017 sea ice area and extent data
« on: May 30, 2017, 11:37:34 PM »
Related question: is there some index that tracks the "cloudiness" if you will, of the arctic? As a new follower of sea ice, I'm trying to get a handle on what a typical season might look like.

Arctic sea ice / Re: IJIS
« on: May 26, 2017, 09:28:18 PM »
Yes! But you said "over much of the arctic". I assumed you were referring to air temperatures, not ice temperatures.

Arctic sea ice / Re: IJIS
« on: May 26, 2017, 08:43:25 PM »
No matter how broken up by winds it has been so far, or how thin it is, it's still below freezing over much of the Arctic. Ice won't melt unless it exceeds the freezing point somehow, whether through bottom melt or surface melt or rain.

This isn't quite true, as insolation can make up the difference of the energy being lost by the ice to the air, I think. That is, it's possible for the ice to be warmer than the air above it with help from the sun.

Arctic sea ice / Re: The 2017 melting season
« on: May 24, 2017, 09:07:08 PM »
Here's the formula for calculating; it's calculated observationally in terms of short and long wave radiation, so implicitly takes albedo into account I guess. And I guess there is a point at which insolation overwhelms the effect of having slightly warmer air which would coincide with lows. In any case, both high pressure AND high temperatures are scheduled for the next few days, so this discussion might not be relevant to the situation at hand.

Arctic sea ice / Re: The 2017 melting season
« on: May 24, 2017, 08:06:16 PM »
Until I see the really warm air invade the Arctic basin for real, I will take current forecasts with a big grain of salt. The high Arctic is still having temps below 0 and will continue to have so for a couple of days ahead. But, if the GFS turns out to be correct the Pacific side should see a major damage in the next 2-5 days.

The main question is how quick the thick snow will dimnish in Siberia and onto the ice.

And GFS continues to be in a bad mood....

It's currently predicting heat in 1-2 days though, and even when poorly performing it would be pretty surprising to see big errors that quickly.

Arctic sea ice / Re: The 2017 melting season
« on: May 24, 2017, 07:51:02 PM »
Recent studies suggest that the atmosphere conditions arctic sea ice properties in spring in a way that may be an important factor in predetermining autumn sea ice concentrations. Here, the role of clouds in this system is analyzed using surface-based observations from Barrow, Alaska. Barrow is a coastal location situated adjacent to the region where interannual sea ice variability is largest. Barrow is also along a main transport pathway through which springtime advection of atmospheric energy from lower latitudes to the Arctic Ocean occurs. The cloud contribution is quantified using the observed surface radiative fluxes and cloud radiative forcing (CRF) derived therefrom, which can be positive or negative. In low sea ice years enhanced positive CRF (increased cloud cover enhancing longwave radiative forcing) in April is followed by decreased negative CRF (decreased cloud cover allowing a relative increase in shortwave radiative forcing) in May and June. The opposite is true in high sea ice years. In either case, the combination and timing of these early and late spring cloud radiative processes can serve to enhance the atmospheric preconditioning of sea ice. The net CRF (April and May) measured at Barrow from 1993 through 2014 is negatively correlated with sea ice extent in the following autumn (r2 = 0.33; p < 0.01). Reanalysis data appear to capture the general timing and sign of the observed CRF anomalies at Barrow and suggest that the anomalies occur over a large region of the central Arctic Ocean, which supports the link between radiative processes observed at Barrow and the broader arctic sea ice extent.

This article suggests what you've said above is true for April, but definitely not late May; if high pressure reduces cloud coverage it implies increased melt due to higher radiative forcing.

Arctic sea ice / Re: The 2017 melting season
« on: May 23, 2017, 10:54:49 PM »
Looks like after tomorrow temperatures should be above freezing in Hudson bay for the next few days. Given the already poor conditions there, might expect some quick melting to occur.

Arctic sea ice / Re: The 2017 melting season
« on: May 21, 2017, 01:10:38 AM »
This might belong in the stupid questions thread, but how long should I trust GFS? Forecast for four days from now indicates some high temperatures heading towards 80N+.

Arctic sea ice / Re: The 2017 melting season
« on: May 17, 2017, 01:35:03 AM »
Pretty dominant high pressure system forecasted by GFS starts in around 5 days and sticks around for a while. Should be fun.

Edit: The image below is 150h.

Arctic sea ice / Re: The 2017 melting season
« on: May 09, 2017, 06:11:50 PM »
This is a week out, so we can wait and see whether it verifies.  Rain smack in the middle of the Arctic seems unusual for mid-May.
     Note that the band of rainfall is forecast to track just poleward of a likely large area of melt ponding (less cloudy part toward left of image).

if you look at the normal >80'N DMI temperature trend, having a large portion of the CAB at above freezing surface temperatures would be, well, shocking to say the least.  I am pretty skeptical about this long-range forecast, though it does indeed fit the projections of GHG forcing and atmospheric circulation changes produced by global warming.

Just for reference's sake, here's what the forecast says for 168 hr. It's the second intrusion of warm air towards the pole.

Arctic sea ice / Re: The 2017 melting season
« on: May 07, 2017, 10:07:42 PM »
Is there a way to track melt pond formation in real time? I've been poking around for products but haven't seen anything, maybe I'm looking in the wrong places.

Arctic sea ice / Re: The Fast Transition
« on: April 29, 2017, 01:04:04 AM »
The snow discussion is getting off-topic. The topic itself is an excellent subject. I believe there are two key questions:
1. Can low ice cover at the end of summer (and/or anomalous accumulated heat in the water) cause significantly lower FDDs during winter?
2. Can lower FDDs and the resulting lower volume translate to low ice cover at the end of summer?
If both answers are true, we will have a fast transition.
The slow transition theory postulated FDDs unaffected by end-of-summer ice cover, cutting the feedback loop.
This year seems to show that  the answer to 1 is yes (though of course it could be just random coincidence). The jury is still out on 2. If we get a low ice cover in Sept, and then low FDDs next winter as well, it will give much more confidence in this fast feedback cycle.

Excellent summary. I might generalize a bit and say: how much of the extra energy accumulated by the oceans in the case of a loss of summer sea ice will stay concentrated in the arctic, and how much will be distributed elsewhere in the earth? Is that a fair question? And if so, what are the main mechanisms by which this energy is distributed? I ask out of ignorance, not because I think the answers are not known.

It seems to me that the assumption is that if there is not already a well understood mechanism causing demonstrating that SIE loss is caused by AGW, it's assumed to be internal (natural?) variability. Is that more or less correct? If so, it's just another example of scientists being conservative. This is fine, but should be emphasized by the media when being reported.

Arctic sea ice / Re: Latest PIOMAS update (March)
« on: March 01, 2017, 06:33:15 PM »
While waiting for PIOMAS update, here is an animation of the ADS/Jaxa sea ice thickness map for February.

Hmm you can see what the shape of what hycom thinks is thicker ice pretty clearly in the ESS and Laptev seas, but JAXA thinks it's the same thickness/thinner than the areas around it, which doesn't make sense to me.

Pages: [1]