Jeff Id at the Air Vent has been doing some interesting work lately. Before the NSIDC Arctic Sea Ice anomaly plot went kaput due to failure of the satellite sensor channel they have been using, they had created a vast archive of single day gridded data packages for Arctic sea ice extent. Jeff plotted images from the data as viewed from directly over the North Pole. It took him over 15 hours of computational time. An example image is below.
Jeff gathered up all the resultant plotted images and turned them into a movie, but placed them on the website “tinypic” where the movie won’t get much airplay.
I offered Jeff the opportunity to have it hosted on YouTube and posted here, where it would get far greater exposure and I completed the conversion this afternoon.
What I find most interesting is watch the “respiration” of Arctic Sea Ice, plus the buffeting of the sea ice escaping the Arctic and heading down the east coast of Greenland where it melts in warmer waters.
Jeff writes:
I find the Arctic sea ice to be amazingly dynamic. Honestly, I used to think of it as something static and stationary, the same region meltinig and re-freezing for dozens or even hundreds of years – not that I put much thought into it either way. Shows you what I know.
This post is another set of Arctic ice plots and an amazing high speed video. The NSIDC NasaTeam data is presented in gridded binary matrices in downloadable form HERE.
The data is about 1.3Gb in size so it takes hours to download, I put it directly on my harddrive and worked from there. The code for extraction took a while to work out but was pretty simple in the end. This code ignores leap years. Formatting removed courtesy of WordPress.
filenames=list.files(path=”C:/agw/sea ice/north sea ice/nasateam daily/”, pattern = NULL, all.files = TRUE, full.names = FALSE, recursive = TRUE)
trend=array(0,dim=length(filenames)-1)
date=array(0,dim=length(filenames)-1)
masktrend=array(0,dim=length(filenames)-1)
for(i in 1:(length(filenames)-1))
{
fn=paste(”C:/agw/sea ice/north sea ice/nasateam daily/”,filenames[i],sep=””) #folder containing sea ice files
a=file(fn,”rb”)
header= readBin(a,n=102,what=integer(),size=1,endian=”little”,signed=FALSE)
year=readChar(a,n=6)
print(year)
day=readChar(a,n=6)
print(day)
header=readChar(a,n=300-114)
data=readBin(a,n=304*448,what=integer(),size=1,endian=”little”,signed=FALSE)
close(a)
if(as.integer(year)+1900<=2500)
{
date[i]=1900+as.integer(year)+as.integer(day)/365
}else
{
date[i]=as.integer(year)+as.integer(day)/365
}
if(i==1)
{
holemask= !(data==251)
}
datamask=data<251 & data>37 ## 15% of lower values masked out to match NSIDC
trend[i]=sum(data[(datamask*holemask)==1])/250*625
}
###mask out satellite F15
satname=substring(filenames,18,20)
satmask= satname==”f15″
newtrend=trend[!satmask]
newdate=date[!satmask]
After that there is some minor filtering done on 7 day windows to dampen some of the noise in the near real time data.
filtrend=array(0,dim=length(newtrend))
for(i in 1:(length(newtrend)))
{
sumdat=0
for(j in -3:3)
{
k=i+j
if(k<1)k=1
if(k>length(newtrend)-1)k=length(newtrend)-1
sumdat=sumdat+newtrend[k]
}
filtrend[i]=sumdat/7
}
So here is a plot of the filtered data:
Here is the current anomaly.
This compares well with the NSIDC and cryosphere plots. This anomaly is slightly different from some of my previous plots because it rejects data less than 15% sea-ice concentration. Cryosphere rejects data less than 10%. In either case the difference is very slight but since we’ve just learned that the satellites have died and are about 500,000km too low, my previous graph may be more correct. I hope the NSIDC get’s something working soon.
All of that is pretty exciting but the reason for this post is to show the COMPLETE history of the NSIDC arctic sea ice in a video. I used tinypic as a service for this 27mb file so don’t worry, you should be able to see it quite well on a high speed connection. It took my dual processor laptop computer more than 15 hours to calculate this movie, I hope it’s worth it. Brown is land, black is shoreline, blue is water except for the large blue dot in the center of the plot. The movie plays double speed at the beginning because the early satellite collected data every other day. You’ll see the large blue circle change in size flashing back and forth between the older and newer sat data just as the video slows down.
After staring at the graphs above you think you understand what is happening as ice gradually shrinks away. Well the high speed video shows a much more turbulent world with changing weather patterns in 2007 and 2008 summer blasting away at the south west corner of the ice. I’ve watched it 20 times at least, noticing cloud patterns (causing lower ice levels), winds, water currents and all kinds of different things. I’m not so sure anymore that we’re seeing a consistent decline to polarbear doom, with this kind of variance it might just be everyday noise.
Maybe I’m nuts, let me know what you see.
No Jeff you aren’t nuts. Here is the YouTube Video, suitable for sharing:
Here is another video I posted on You Tube last month which shows the flow of sea ice down the east coast of Greenland. Clearly there is more at work here than simple melting, there is a whole flow dynamic going on.
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Great video! Two things that stand out when you play the whole thing is that wintertime ice used to get thick off of Newfoundland in the winter, but in the last decade, not so thick. The other thing is that you can visually see that 2008, although there was more ice than in 2007, was still pretty low, historically. But let’s see what this coming year brings in the summer…..
Beautifully done. Certainly gives some needed perspective.
(Here’s some irony: there’s an add beneath this post advertising carbon offsets)
What would be really instructive is to superimpose jet stream archive data (they have it back to 1996 for the Arctic area) on this video.
Al Gore debunked!, whenever somebody says artic will melt in 5 years just show the video.
Not really historically. Historically would be 1000, 2000, or more years, even than is a snapshot in geological time. 20 or 30 years is pretty meaningless.
Congratulations on another terrific piece of work. It’s amazing how this seemingly simple change in presentation greatly enhances the ability to comprehend what’s really occurring in the Arctic ice cycle.
I would suggest that the reason the wind and waves can move the ice more in recent years is because it is now thinner.
The next step is to measure the angular momentum of the ice pack over time. I can see a lot of rotation in the later years.
Well done, that’s fantastic!
Hmm. Not much plot, but still way better than watching “Ishtar.” Definitely two thumbs up.
Nathan,
it is thinner because the wind and waves were moving it while it was thicker. In the last few hundred years it apparently has never been thick enough for a permanent ice cap to form.
NASA reported that the Arctic was losing ice at about 193,000km2/year up till 2000. From 2000 till 2007 it was about double that. Without the 20 years of thinning the higher loss after 2000 would not have been as large.
Of course, the loss has, at least temporarily reversed. Willing to bet your future on a short, incomplete, data set and study??
Fascinating. On my first view I noticed a prong of ice (in some years) growing eastward from Greenland at about 70 degrees N. or so. At least once either ice or clouds seem to break away from this. Others may have a comment about this. It is just my first look and observation. If you are watching other areas, say Hudson Bay filling with ice, you will miss this. I have some other things to do before dark so I’ll have to look again later.
Nathan (18:44:20) :
I would suggest that the reason the wind and waves can move the ice more in recent years is because it is now thinner.
I would suggest that thickness has very little to do with it. The thickness relative to mass and depth of water under it is miniscule. My experience with freshwater lakes and rivers suggest to me that if the forces are there to move it, it will move.
OT – Tomorrow I’m driving to Washington and will be attending the Third Int’l Conference on Climate Change Tuesday. – Cool!
Glenn @ur momisugly NoFreeWind
I’m no expert but to my addled brain the little film-thingy showed ice reducing in extent in summer and expanding in extent in winter with virtually no difference from year to year.
What was also obvious was that the pattern of ice always depicted the face of Susan Boyle, but it is YouTube so I suppose that’s compulsory.
And now this is announced…
http://www.uticaod.com/archive/x1175994993/May-to-go-out-under-a-freeze-watch
Interesting. There’s not a single winter where the ring centered on the North Pole formed by Alaska, Canada, Greenland, Franz Joseph land, and Siberia isn’t packed solid with ice. All the variation is due to ice in the Atlantic and Pacific.
Thank you JeffID!!
I’ll be watching until mid September to see what happens to 2009 melt. Here’s JAXA today :
http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm
I’ve got my popcorn ready!
Nathan (18:44:20) :
I would suggest that the reason the wind and waves can move the ice more in recent years is because it is now thinner.
This is one of the many reasons why any recovery in the arctic sea ice should be noteworthy. The whole thing is just FULL of positive feedback effects. Low sea ice should lead to lower sea ice without any change in temperature. Furthermore, simply holding at a warmer temperature than was normal say, 30 years ago should lead to steady melting, year after year after year. Temperature should drive the first derivative of sea ice (in a simple minded model anyway).
Any reversal would be completely counter to all AGW theories. If anything the Arctic Sea ice loss should be ACCELERATING. That’s why Gore made his confident prediction about an ice-free north pole. From his point of view, it’s a sure bet.
If it doesn’t come through something HAS TO BE hugely amiss with his point of view.
Golly.
Try these truly amazing timelapses seaice pictures The Big files are realy worth Downloading
http://polynya.gsfc.nasa.gov/animations/amsr
Then for the southern hemisphere try the 480 MB file to watch icebergs on the move:
http://polynya.gsfc.nasa.gov/animations/amsr_south/
Nice work JeffId at Air Vent
For animations on the Arctic and Antarctic ice caps for last 21 days ~1mb AVI
For period Jan 2003 to date (not quite – to date) ~ 20mb AVI
Every day map updates on sea ice cover for the Arctic and Antarctic
http://www.iup.uni-bremen.de:8084/amsr/amsre.html
Also more detailed area maps around both the North and South poles (see the route of the Russian floating weather station NP-36, which you can also Google for real time position and weather data). If there is grey streaks on the area your interested in, come back later, as it updates to fill in those areas.
Don’t forget that there is webcams in eg Antarctica – USAP McMurdo base (night time at present) :http://www.usap.gov/videoClipsAndMaps/mcmwebcam.cfm
And in areas such as Svalbard (Spitzbergen), Greenland, Moscow and northern areas of the US
me too tx Jeff
Just a nice piece of work. Thank you.
Nice video. So, even if the ice totally melts up there one summer, it only takes a few extra cold years to bring it back.