Daily SMOS Ice Thickness available: season 2015/2016

[Wipneus]

From the Uni Hamburg Integrated Climate Data Center:

New Data: SMOS Sea Ice Thickness 20.09.2013
By: Stefan Kern

Now, after almost 4 years of operation of the Soil Moisture and Ocean Salinity (SMOS) satellite, we can offer daily sea ice thickness estimates calculated from SMOS data for the Arctic for freezing seasons 2010/11 to 2012/13 via the ICDC web portal:

http://icdc.zmaw.de/l3c_smos_sit.html?&L=1.

SMOS is European Space Agency’s (ESA) Soil Moisture and Ocean Salinity mission measuring the Earth radio emission at 1.4GHz. At this frequency ice is semi transparent, so the measured brightness can be used to calculate thickness.

Important disadvantages are 1) only measures thin ice up to about 0.5m 2) not usable in the melting season (15 April-15 Oktober).

Do read the "Data Quality" section in the link given above when interpreting the SMOS data.

[Jim Hunt]

Most interesting. Thanks for the heads up Wipneus.

Will October 2013 data become available "in real time"?

[Wipneus]

Most interesting. Thanks for the heads up Wipneus.

Will October 2013 data become available "in real time"?

That would be interesting indeed, but I have not seen an indication how frequently they plan to update.
The calculation needs surface air temperature which comes from a reanalysis. So some delay is unavoidable.

[anonymous]

Will October 2013 data become available "in real time"?

At least the brightness temperature data updates every day 9:00 UTC: https://icdc.zmaw.de/thredds/catalog/ftpthredds/smos_tb/2013/09/catalog.html

[seaice.de]

We will soon update the SMOS ice thickness with a similar latency as the brightness temperature. 


Cheers

Lars

[anonymous]

We will soon update the SMOS ice thickness with a similar latency as the brightness temperature. 

Highly appreciated.

[Jim Hunt]

We will soon update the SMOS ice thickness with a similar latency as the brightness temperature. 

Much appreciated here too Lars!

[Neven]

Spam removed, thanks everyone.

[ChrisReynolds]

Spam removed, thanks everyone.

Or so he thought....



Reported to moderator as SPAM.

[Neven]

I think I'll that one stand. 

[seaice.de]

Now the process is up and running. 

[Wipneus]

Now the process is up and running. 

Thanks a lot guys.

At first I was looking at a wrong ftp directory, but the NetCDF data is here

[anonymous]

Interesting to compare against Ascat. A bit hidden in shades of blue are the long and slim patches of MYI that broke off direction Beaufort. Checked against wind data, looks plausible.

[Wipneus]

A bit hidden in shades of blue are the long and slim patches of MYI that broke off direction Beaufort.

We have to be careful with interpretations here, those shades of blue are above 0.5m the upper limit that SMOS can "measure" thickness.

For the moment I cut everything above 0.6m off to concentrate on what SMOS can measure.
The attached animation does indicate (with more confidence than the amsr2 images) that the Fram Strait transport is filling up the northern Greenland Sea.

(click on attached image for an animation)

[anonymous]

Wipneus, I know, and there is an error reported with each pixel. But the min/max of the "shades of blue" in the mentioned region are large enough for me to investigate. If a thickness pattern remains over several days I'm quite sure it is real, whether the absolute thickness is correct is another question.

Currently I exclude everything below 3cm and above 150cm. That gives me moving clouds faking thickness changes, but even above 100cm some structures remain or reappear.

[Wipneus]

27 January sea ice thickness by SMOS.

Top 2011 & 2012
Below 2013 & 2014

[jdallen]

27 January sea ice thickness by SMOS.

Top 2011 & 2012
Below 2013 & 2014

Interesting, Wipneus.  One thing that I don't see is any obvious correlation between the year over year state of the ice at this juncture, and what happened during the following melt season.

[Wipneus]

Animation covering Februari (26 and 28 are missing). I have added some grey's for thickness up to 1.5m, these may indicate some ice property but probably not thickness. Above 0.5 meter there just isn't enough detectable signal. It might give some indication on ice movement though.

The big ice retreat in the Barents sector and around Svalbar can be viewed from ice thickness point of view. A rather permanent low thickness band in the Laptev Sea can be seen, it includes a polynya near the Severnaya Zemlya islands. Probably not unusual if you look at my previous post.

(click the attached image for the animation)

[Neven]

Very interesting stuff, Wipneus! Somehow I overlooked this thread or forgot about it.

[Wipneus]

Thanks, here is thickness by SMOS on the first of March 2011-2014.

(reminder: SMOS can only calculate thickness up to about 0.5m. The grey's in the images are probably not an indication of thin ice)

[seaice.de]

This short tutorial explains how to access SMOS datasets with the OpenNDAP protocol:
http://earthpy.org/smos_sea_ice_thickness.html

Cheers

Lars

[Jim Hunt]

A noobie question for Lars and/or Wipneus.

If I look at the two GIFs available at https://icdc.zmaw.de/thredds/catalog/ftpthredds/smos_sea_ice_thickness/catalog.html it seems as if the uncertainty is greater than the thickness. Have I completely misunderstood things, or are the titles of the two charts back to front, or is my initial interpretation in fact correct?!

[crandles]

A noobie question for Lars and/or Wipneus.

If I look at the two GIFs available at https://icdc.zmaw.de/thredds/catalog/ftpthredds/smos_sea_ice_thickness/catalog.html it seems as if the uncertainty is greater than the thickness. Have I completely misunderstood things, or are the titles of the two charts back to front, or is my initial interpretation in fact correct?!

We have to be careful with interpretations here, those shades of blue are above 0.5m the upper limit that SMOS can "measure" thickness.

If I interpret that correctly if the ice is over 0.5m thick, SMOS has no idea how thick so a range of 0.5m to 20m or however high ridges get these days would be an appropriate range. So a lot of the area is shown as >1m +/- >1m should be interpreted as >0.5m up to as high as ridges get in that area.

It perhaps has more potential to be useful around the edges with thin ice (but perhaps a rather larger proportion of the area in late summer).

Does 0.3m +/- 0.7m mean anything up to 1m?

if so 02m +/- 0.6m means anything up to 0.8m and is slightly more likely than not to be thinner than 0.3m +/- 0.7m.

This doesn't seem as if it gives a huge amount of information but maybe it is better towards the minimum?

[Wipneus]

Both an animation of the last 3 weeks and a collage of March 14 of 2011-2014.

(remember SMOS measures only thin (< 0.5m) ice, variations above that (the grey's) are probably not an indication of thickness)

(I had to make the animation small, somehow the normal sized version did not work )

[Wipneus]

The collage in a separate post.

[Neven]

WN, in the collage Bering and Okhotsk seem to be cut off in all years except 2014. Is there a reason for that?

[seaice.de]

WN, in the collage Bering and Okhotsk seem to be cut off in all years except 2014. Is there a reason for that?

We changed the processing and extrapolated the salinity from the ocean model. The currently used ocean reanalysis configuration does not include the Pacific.

Lars

[seaice.de]

The collage in a separate post.

By the way, the SMOS ice validation is going on:

http://blogs.esa.int/campaignearth/2014/03/21/smos-ice-hacking-off-the-ice-to-begin-validation/

[Wipneus]

New animation of three weeks of SMOS sea ice thickness development.

(animation starts after you click the picture)

[Wipneus]

And an image comparing SMOS sea ice thickness 2010-2014.

As before: SMOS gives information of ice thickness in a range below 0.5m. The "grey" part of the scale may indicate other parameters than thickness.

[DaddyBFree]

Thanks for the comparisons Wipneus!

[Neven]

Yes, they are awesome. I will use the next comparison for my winter analysis.

[Wipneus]

Yes, they are awesome. I will use the next comparison for my winter analysis.

Yes, April 15 the SMOS season will end.

[andy_t_roo]

A noobie question for Lars and/or Wipneus.

If I look at the two GIFs available at https://icdc.zmaw.de/thredds/catalog/ftpthredds/smos_sea_ice_thickness/catalog.html it seems as if the uncertainty is greater than the thickness. Have I completely misunderstood things, or are the titles of the two charts back to front, or is my initial interpretation in fact correct?!

We have to be careful with interpretations here, those shades of blue are above 0.5m the upper limit that SMOS can "measure" thickness.

If I interpret that correctly if the ice is over 0.5m thick, SMOS has no idea how thick so a range of 0.5m to 20m or however high ridges get these days would be an appropriate range. So a lot of the area is shown as >1m +/- >1m should be interpreted as >0.5m up to as high as ridges get in that area.

It perhaps has more potential to be useful around the edges with thin ice (but perhaps a rather larger proportion of the area in late summer).

Does 0.3m +/- 0.7m mean anything up to 1m?

if so 02m +/- 0.6m means anything up to 0.8m and is slightly more likely than not to be thinner than 0.3m +/- 0.7m.

This doesn't seem as if it gives a huge amount of information but maybe it is better towards the minimum?

if there is a large error in small values, it is a constant bias, rather than noise; if you watch animations (like what is posted a few posts back) areas which are thin are consistently thin, they don't have lots of rand snow-noise as the error changes from one measurement to the next.

[Neven]

Andy, sorry for releasing your comment so late. Due to problems with spam, first comments by new members are withheld until approved by me. I thought I would get notified, which is why I saw your comment just now.

[Wipneus]

This should be the last SMOS animation of the season, yet the data keeps coming in after April 15 when it stopped in previous years.
So here is the animation until the 17th. Note the crack in the East Siberian Sea and the retreat in the Bering and Barents seas.

(click the picture for that animation)

[Wipneus]

And a collage of the SMOS maps of April 15 for the last 4 years.

(again be careful with interpreting the "grey" shades as SMOS cannot see beyond 0.5 meter of thickness)

[Neven]

Thanks for that image, Wipneus. I'll use it for the winter analysis, although it's difficult to assess the situation compared to previous years. Differences seem to be minimal. Too bad SMOS stops now. A couple of weeks more would be really useful.

[Shared Humanity]

Does this mean that the gray shaded areas are ice that is 0.5 meters or less? If this is so than 2014 looks better in this regard than the 3 years that have preceded it.

[Wipneus]

Does this mean that the gray shaded areas are ice that is 0.5 meters or less? If this is so than 2014 looks better in this regard than the 3 years that have preceded it.

Gray ice is at least 0.5 m thick. That is all we know.

[Wipneus]

The SMOS data should have ceased coming in by the 15th, yet it did not.
In the animation (up to the 26th) some images are (partially) missing though.

(click that picture for the animation)

[Wipneus]

SMOS updates, unavailable during the melting season, have resumed. Here is the first one.

(the SMOS instrument can measure ice thickness up to 0.5m, anything above that may not be related to ice thickness).

[ChrisReynolds]

Thanks Wipneus, I was going to ask when this data would start flowing.

[Wipneus]

Here is an animation of the first SMOS thickness images of the season (20th of October missing).
Things to watch:
-the start of the Beaufort Gyre
-flash freezing of the Kara Sea
-quick thickening in the Canadian Archipelago
-lack of refreezing on the Pacific side (Beaufort, Chukchi, East-East Siberian Sea)
-little Fram export

(click to start the animation)

[Wipneus]

And here a collection of SMOS thickness images on October 21 of the past five years.
The 2014 situation has a bit of the previous 4 years, but what may be different is the greater extent in Kara, the thicker ice in the CAA and the very low levels of refreezing on the Pacific side (especially the ESS).

[Wipneus]

An animation of ice thickness as monitored by the SMOS instrument.
What can be seen:
- fast closing of the Laptev open water by thin ice
- retreat of ice extent in the Barents and Greenland Seas
- thickening of the ice in Kara and (west) East Siberian Seas

(animation will start after a click)

[Wipneus]

And a composition of 5 years of SMOS thickness at the 28th of Ocotber.

[Wipneus]

Animation of SMOS ice thickness in the past 10 days. What can be seen:
-thickening in the Laptev and East Siberian Seas, the western part is curiously staying open;
-not so much in Kara anymore;
-expansion in the Barents and Beaufort Seas;
-lack of large scale ice movement

[Wipneus]

And a comparison of the SMOS derived ice thickness on November 4. The open state in the westtern part of the East Siberian Sea is unique in this collection.

[mark]

I had a look today at the 30day speed and drift chart and the movement of ice has been very anticyclonic in nature for a good while - may explain that unique gap in the ESS, but this is due to peak over the next day or so before Nuri is predictd to move across the ESS area. Those strong flows are then due to cease ending with a forecast, strong, more linear movement from the beaufort towards the Fram/Barents area. Will be interesting to see just how a change from one strong flow to another will affect the ice free areas still left in the ESS