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dominik lenné
Berlin, Germany
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How does PIOMAS deal with such a dispersed and at the same time compacted ice mass?
2016 Arctic cyclone, update 3
Two days have passed since the previous update, and in those two days the storm re-intensified, bottomed out at 971 hPa (slightly higher than the first lowest central pressure of 968 hPa), as can be seen on the image on the left, provided by Environment Canada. It quickly weakened after that, bu...
There is an interesting analysis at taminos blog:
https://tamino.wordpress.com/2016/07/17/arctic-heat/
in case no one other has noticed it.
2016 melting momentum, part 3
Melting momentum, it's what I call the absorption of heat and solar radiation during May and June that does not directly lead to melt and a reduction in ice cover, but rather comes into play during July and August (I had a more wordy explanation last year). This is part 3 in the series. As we s...
Since 2010, there are signs of a change of the annual cycle towards a more rapid, deeper melt in late spring offset by a stronger freeze up in autumn. So the amplitude of the annual volume oscillation increased apparently.
This is to be expected for a state with higher air temperatures: higher melt rates in summer because of the air temperature and higher freeze rates in winter because of the thinner ice.
PIOMAS July 2016
Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center: As expected after a month of stalling sea ice extent and weather that generally isn't conducive to se...
This is really exciting! Very good decision!
Steve Bloom reporting from 2014 AGU FM
A while ago, commenter and now guest blogger Steve Bloom offered to visit the 2014 American Geophysical Union's Fall Meeting, starting tomorrow and ending on Friday, and report for the ASIB on interesting presentations concerning the Arctic. Unfortunately the AGU Public Information Office has t...
Hello,
from somewhere i got the idea to connect the atmospheric warming "hiatus" to the heat necessary to melt the 8000 km³ of perennial ice lost during the last 20 years or so.
The calculations can be found here: http://remarksandobservations.wordpress.com/2013/11/15/global-warming-hiatus-it-might-be-the-ice/
What do You think of that?
The 'hiatus' and the Arctic
There's a new research paper out that will probably set the blogosphere ablaze in coming days, especially the fake skeptic part of it. Why? Because it espouses a theory that explains the slowdown in the rate of temperature rise of the past decade and a half (depending on your starting point). A...
4.5 e6 km² - correctig myself as I got it wrong, which data source is the reference.
Crowd-Source Prediction of Mean September Sea Ice Extent (July update)
Each June, July and August, the SEARCH Sea Ice Outlook (SIO) collects predictions for the mean extent of Arctic sea ice in September. These predictions come mainly from scientists but also some other people, drawing on a variety of modeling, statistical or subjective methods that each contributo...
Question to Neven:
jaxa, dmi.dk and norsex deliver quite different values for the same year. Which will be the reference for our guesses in the end?
Crowd-Source Prediction of Mean September Sea Ice Extent (July update)
Each June, July and August, the SEARCH Sea Ice Outlook (SIO) collects predictions for the mean extent of Arctic sea ice in September. These predictions come mainly from scientists but also some other people, drawing on a variety of modeling, statistical or subjective methods that each contributo...
5.0 e6 km²
PIOMAS volume looks a little bit better than 2011. Practically all SIE curves look a little bit better than 2011. Supposing continuous weather change tending to more melting - which I did not check - I just take the 2011 value. Jaxa leads to 4.6 or so, dmi.dk yields 5.0 or so, norsex 5.4 or so, so I jump right in the middle and take five.
Crowd-Source Prediction of Mean September Sea Ice Extent (July update)
Each June, July and August, the SEARCH Sea Ice Outlook (SIO) collects predictions for the mean extent of Arctic sea ice in September. These predictions come mainly from scientists but also some other people, drawing on a variety of modeling, statistical or subjective methods that each contributo...
With all this westerly highs we might approach another appalling summer with northerly winds in western/central europe - brrr - don't like climate change if it turns out this way.
If this is real...
As usual, it's all about the if. Allow me to explain what this is about: In the first Arctic Sea Ice update of the 2013 melting season that was posted a couple of days ago, I announced that a cyclone was forecasted to move over the Arctic Basin and stay there for a while. It's been there for a c...
Looking at the PIOMAS volume anomaly curve, one sees three distinct downward peaks in the last 3 springs/summers. The last 3 years, the volume development over the year was definitely and consistently different from the mean.
This could be another indication of a new state of the weather system, although those are at most semi-stable.
The coming summer will corroborate - or weaken - the assumption of a new weather state. My personal guess is 0.6 probability for a corroboration.
The Four Charts That Really Matter
Guest post by R. Gates Recently on Judith Curry's blog, a guest post was submitted by DocMartyn which was a rather nicely (from a math perspective) done extrapolation of past tropospheric temperature trends and cycles out to 2040 and beyond. It was essentially a nice job of, as he put it, "gra...
Concerning the map: my favorite is the Goode approach, an equal area projection minimizing the distortions at the price of cutting the map up.
http://en.wikipedia.org/wiki/Goode_homolosine_projection
Sudden Stratospheric Warming: Causes & Effects
Introduction & Disclosure My name is Randall Gates Simpson. There is no PhD after my name and I am not a PhD climate scientist. I don't consider myself a traditional "expert" on the subject of SSW's because of my lack of official credentials. I do however think I probably know quite a bit more ...
This Cryosat data release story is absolutely sensational, a true scoop!
CryoSat-2 reveals major Arctic sea-ice loss
We knew that observations by the CryoSat-2 satellite were by and large confirming the modeled data from the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center, because of the recent publication in GRL of Laxon et al.'s CryoSat-2 estimates of Arctic sea i...
Found the problem - a ")" at the end included in the URL.
http://www.physicalgeography.net/fundamentals/6i.html
is correct.
2013 Open thread #1
I was planning on writing posts more regularly, but reality forbids. So here's an open thread for all of your off-topic banter. source: Space Daily Will be back next week when I get an Internet connection in our new apartment. There's plenty to write about: that science report, the lower albe...
@bouke van der spoel: your link to physical geography seems not to work - could you repost it?
2013 Open thread #1
I was planning on writing posts more regularly, but reality forbids. So here's an open thread for all of your off-topic banter. source: Space Daily Will be back next week when I get an Internet connection in our new apartment. There's plenty to write about: that science report, the lower albe...
@SATire: Most of "Spiegel"- commenters (and everywhere in the world) just can't deal with uncertainty. They didn't learn it. They have no feeling to weight the importance of this or that kind of news. They are lost and resort to dumb boldness, just to reinstall their feeling of self security.
To blame are partly the media, which prefer clear and dramatic news over subtle and sound analysis and, after all, are made by journalists who themselves all too often didn't learn do deal with uncertainty.
But fortunately the dumb-bold type - though often dominating the comment columns of newspaper websites - seem to be a minority.
2013 Open thread #1
I was planning on writing posts more regularly, but reality forbids. So here's an open thread for all of your off-topic banter. source: Space Daily Will be back next week when I get an Internet connection in our new apartment. There's plenty to write about: that science report, the lower albe...
Not only sea ice but also snow cover development isn't reflected in numerical models:
http://www.nature.com/news/arctic-snow-cover-shows-sharp-decline-1.11709:
"Derksen says that scientists need to understand why the observed changes do not match up with the projections of widely used models. He found that the snow-cover projections generated by the climate models being used in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change underestimate the extent of spring snowmelt in the Northern Hemisphere. 'Even if we’ve become a bit more willing to be aggressive with the scenarios we use to drive these models, it still doesn’t seem to be enough to describe what we’re observing,' says Sharp."
Arctic snow cover shows steep decline
From LiveScience: Arctic Snow Cover Shows Steep Decline The blanket of snow that covers Arctic regions for most of the year has been shrinking at an increasing pace over the past decade, researchers say. A recent study found an overall decrease in Arctic snow-cover extent (snow that covers th...
Thinking about it, I had to give my original blog post an overhaul.
As often, things are more complex than they appear at first sight:
The snow data are “extent” – data which means, that they contain 10 – 15 % snow free area (not 100% sure about this point).
The albedo of land is bigger than that of water (ca. 0.2 vs. ca. 0.1,http://www.climatedata.info/Forcing/Forcing/albedo.html).
Contrary to intuition, the mean solar irradiation in mid summer in those areas, where the main snow melting difference occurs (around the 60° N) is lower than on the polar sea around the north pole!(http://tamino.wordpress.com/2012/10/01/sea-ice-insolation)
The data for other months than June are not given in my source, probably in the paywalled original paper, so they might look less crassy.
On the other hand, the capacity of heat absorbtion of land is smaller than that of sea surface, which will direct the absorbed energy earlier into atmosphere instead of the water body. Also, the speed of recent summer snow loss seems to be higher than that of sea ice.(http://www.livescience.com/26091-arctic-snow-cover-decline.html)
Arctic snow cover shows steep decline
From LiveScience: Arctic Snow Cover Shows Steep Decline The blanket of snow that covers Arctic regions for most of the year has been shrinking at an increasing pace over the past decade, researchers say. A recent study found an overall decrease in Arctic snow-cover extent (snow that covers th...
This is all quite heavily OT, but anyway:
With cap&trade vs. carbon tax, there are pros and cons for each.
Predictability: there are statistical ups and downs of energy price anyway, which make planning for industry difficult. On first look, a thoroughly planned rising carbon tax gives more predictability. But c&t can act stabilizing on economy, as with low demand, the certificate price will drop also.
Ease of implementation: carbon tax wins, but: noone knows which tax path yields which emissions reduction path. With c&t, reduction is well-defined.
At the end of the day, these are details of lesser importance. Hansens proposition is perfectly tailored for the notoriously state hating US. If it is necessary to make enough GOP diehards to embark on climate saving, it's the best.
Arctic snow cover shows steep decline
From LiveScience: Arctic Snow Cover Shows Steep Decline The blanket of snow that covers Arctic regions for most of the year has been shrinking at an increasing pace over the past decade, researchers say. A recent study found an overall decrease in Arctic snow-cover extent (snow that covers th...
http://ocean.dmi.dk/arctic/meant80n.uk.php
shows consistently warmer winters the last years which cost us 5 - 10% freeze rate.
PIOMAS January 2013
Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center: 2012 has ended the year with a total volume that's around 1000 km3 less than 2010 and 2011, but ther...
@Aaron: You spoke of freshwater lenses under the ice (supposedly MYI). Where they melt water from the last summer, staying at place, or river influx (then only at the fringes)? Just for my understanding.
@crandles: Yeah, wasn't aware melt is mainly radiation driven and then those absorbtion effects kick in.
"Um the freeze rate determines the maximum, which seems a strange thing to call a baseline."
The idea behind is that a stationary minimum summer thickness for a given sort of year supposed to repeat itself a number of times is where winter freeze-up and summer melt-down equal. Both depend on summer minimum thickness. So I called this "baseline of the thickness oscillation".
If there is no summer thickness of course a "baseline" makes no sense.
The absorbtion increase of thin ice neutralizes somehow the stabilizing effect of fast freezing and make the temperature dependency of summer ice thickness much more hefty.
Looking for winter weirdness 5
From WattsUpWithThat (via Pierre Gosselin and Marc Morano): Increased evaporation combined with more heat loss in the Arctic due to a record low amount of Arctic sea ice is the likely cause. The likely cause of this: This graph is made and updated by the Rutgers University Global Snow Lab. Th...
The thickness growth rate of thin ice - with all other conditions kept constant - is bigger than that of thick ice. The effect of 10 cm ice more or less is most pronounced if the ice is thin; the thickness-freeze-rate-relation of thick ice is much weaker.
So the effect of a late freeze start on maximum thickness is diminished by this, but not cancelled out. The thickness-freeze-rate-dependency is stabilizing the ice sheet.
(Also, it is one function, which determines the baseline of the thickness oscillation. The other is melt rate, which has a weak thickness dependency, afaik.)
Looking for winter weirdness 5
From WattsUpWithThat (via Pierre Gosselin and Marc Morano): Increased evaporation combined with more heat loss in the Arctic due to a record low amount of Arctic sea ice is the likely cause. The likely cause of this: This graph is made and updated by the Rutgers University Global Snow Lab. Th...
There is not only a spring- and summer- snow cover feedback from less snow.
More snow _on the ice_ in winter will decrease ice thickness growth rate, as it will prevent the heat from below to escape to the atomsphere.
Looking for winter weirdness 5
From WattsUpWithThat (via Pierre Gosselin and Marc Morano): Increased evaporation combined with more heat loss in the Arctic due to a record low amount of Arctic sea ice is the likely cause. The likely cause of this: This graph is made and updated by the Rutgers University Global Snow Lab. Th...
I can't help but I dislike the attribuition of any event, be it a storm or a winter, may it have soandso many people killed, be they as improbable as it may be, to global warming. It all sounds sensational and interesting, but under the bottom line I only trust statistics.
There have been harsh and early winters before in Russia, e.g. the one that helped keep the German Army 1941 from taking Moscow.
Looking for winter weirdness 4
Here's a small one, related to the previous winter weirdness post. Apparently China is also experiencing a colder winter than usual. Allow me to just copypaste the entire article from China Daily: China's cold winter linked to Arctic sea ice loss The unusually cold winter this year in China m...
I drew a little bit of Flak because of the somewhat megalomanic proposition with the mass-produced thickness sensors. I was of course well aware that an outsider project of such size, which may or may not work out, has no real chance.
AFAICS the 70s-Sandia-penetrator project was a ballistic penetrator with deceleration sensors radioing its data up during or after impact - not a soft landing automatic station meant to remain stationary for months.
It may have a lot of problems hard to solve but surely not deceleration on impact, as Peter Ellis so sarcastically suggested.
Could be an interesting interdisciplinary development project of higher level science, engineering and manufacturing technology students...
So, and now I give You a break with this.
The real AR5 bombshell
The whole fake skeptic propaganda effort disguised as 'leak' is boring me to death, but of course it's interesting to have a sneak peek preview of the IPCC Fifth Assessment Report (AR5) and see what they will have to say about Arctic sea ice. Geoff Beacon from the Brussels Blog already had a g...
Concerning volume: If it's not taken by IPCC (I did not read the draft and also, there will surely be modifications) then for the simple reason, that it cannot be measured directly and so any data have a pretty wide uncertainty bar and are open to attack. A very unsatisfactory situation for years now.
I propose herewith to invent cheap mass produced air droppable floating ice probes, which drill automatically a sensor stick through the ice and keep track and transmit ice & snow thickness, salinity, temperature, radiation balance. Then spray the ice sheet with thousands of them.
In the end cheaper than cryosat, and very lsmall error bars at least pointwise.
A few million Euros - one single cleanroom lab for semiconductor processing costs several times this amount.
The real AR5 bombshell
The whole fake skeptic propaganda effort disguised as 'leak' is boring me to death, but of course it's interesting to have a sneak peek preview of the IPCC Fifth Assessment Report (AR5) and see what they will have to say about Arctic sea ice. Geoff Beacon from the Brussels Blog already had a g...
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