Snow And Ice In The Northern Hemisphere Autumn/Winter 2015/16

[BornFromTheVoid]

I do a weekly update on the Arctic sea ice situation over in the climate science area, for anyone interested, here's the latest one from yesterday https://forum.netweather.tv/topic/74411-arctic-ice-data-and-stats/?p=3284085

[throwoff]

I really didn't expect to see us lagging behind 2014 on that chart especially when the images show the ice being far more widespread this year. 

 

I wonder where the breakdown in data comes from?

[BornFromTheVoid]

I really didn't expect to see us lagging behind 2014 on that chart especially when the images show the ice being far more widespread this year. 

 

I wonder where the breakdown in data comes from?

 

2014 had much more ice in the Kara/Barents region, to the north of Scandinavia.

 

You can use the link below to compare the ice concentration on different dates.

 

http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=11&fd=13&fy=2014&sm=11&sd=13&sy=2015

[throwoff]

Some serious growth on the latest.

 

 

 

[Midlands Ice Age]

2014 had much more ice in the Kara/Barents region, to the north of Scandinavia.

 

You can use the link below to compare the ice concentration on different dates.

 

http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=11&fd=13&fy=2014&sm=11&sd=13&sy=2015

 

BFTV

 

After ThrowOff  postings as above on the Northern Hemisphere  sea and ice maps, I decided to try and investigate the situation. Particularly as his comments with regard to the ice extents appeared to be correct (from his maps)..

 

First point I noticed is that your charts are referring to Arctic sea ice and from what i would guess are  the 15% sea ice extent figures, whereas Throw off is talking about the northern hemisphere (what concentration?). Is there any difference?

 

The reason is as Throw off suggested the maps he shows don't agree with you hypothesis.There is clearly more ice in the northern hemisphere this year than last.!!!

 

So I went to MAISIE to get the actual ice figures by region.

 

Reproduced here for 2105/11/16 (Day 319) with figures for comparison with last year. Also notice that MAISIE from what I can see is based upon 30% ice coverage. (as compared to NSIDC who in their charts quote  15%). 

 

Also for comparison the NSIDC extent charts are still way below 10 million k squared. (whereas at a greater concentration requirement MAISIE is showing more than this amount of ice).

 

Maisie data -

 

 Area                   Northern Hemisphere           Kara         Barents        Hudson Bay         Greenland      Baffin Bay  Arctic general

2015                   10,465,392                         757,761      98,697           456,282              550,602          795,562      3,173,998

2014                   10,345,368                         879,020      508,175         312,335              469,679          426,417      3,243,450

 

So as you can see, from the last column the general arctic area is running lower this year, mainly due to Kara (120K) and Barents (410K). The other regions though more than outweigh these shortages this year, with Hudson Bay (140K), Greenland sea (80K) and particularly Baffin Bay at (370K).

 

Which seems to tie in more with the charts as supplied by Throwoff above that there is more ice in the northern hemisphere this year than last....

 

So my question(s) to you are 1)  Are your figures based upon 15% or 30%. sea ice concentrations?

2) What areas are included in your charts/ graphs of Arctic sea ice?.

 

Should we be looking at northern hemisphere ice rather than just the Arctic basin for more accurate assessments of sea ice extent.

[BornFromTheVoid]

BFTV

 

After ThrowOff  postings as above on the Northern Hemisphere  sea and ice maps, I decided to try and investigate the situation. Particularly as his comments with regard to the ice extents appeared to be correct (from his maps)..

 

First point I noticed is that your charts are referring to Arctic sea ice and from what i would guess are  the 15% sea ice extent figures, whereas Throw off is talking about the northern hemisphere (what concentration?). Is there any difference?

 

The reason is as Throw off suggested the maps he shows don't agree with you hypothesis.There is clearly more ice in the northern hemisphere this year than last.!!!

 

So I went to MAISIE to get the actual ice figures by region.

 

Reproduced here for 2105/11/16 (Day 319) with figures for comparison with last year. Also notice that MAISIE from what I can see is based upon 30% ice coverage. (as compared to NSIDC who in their charts quote  15%). 

 

Also for comparison the NSIDC extent charts are still way below 10 million k squared. (whereas at a greater concentration requirement MAISIE is showing more than this amount of ice).

 

Maisie data -

 

 Area                   Northern Hemisphere           Kara         Barents        Hudson Bay         Greenland      Baffin Bay  Arctic general

2015                   10,465,392                         757,761      98,697           456,282              550,602          795,562      3,173,998

2014                   10,345,368                         879,020      508,175         312,335              469,679          426,417      3,243,450

 

So as you can see, from the last column the general arctic area is running lower this year, mainly due to Kara (120K) and Barents (410K). The other regions though more than outweigh these shortages this year, with Hudson Bay (140K), Greenland sea (80K) and particularly Baffin Bay at (370K).

 

Which seems to tie in more with the charts as supplied by Throwoff above that there is more ice in the northern hemisphere this year than last....

 

So my question(s) to you are 1)  Are your figures based upon 15% or 30%. sea ice concentrations?

2) What areas are included in your charts/ graphs of Arctic sea ice?.

 

Should we be looking at northern hemisphere ice rather than just the Arctic basin for more accurate assessments of sea ice extent.

 

The charts posted by throwoff show extent (15% concentration or greater) for lakes and ocean and come from the IMS. They use multiple different sources of data which have changed over time, and are not created for historical comparisons. If they change the data source, instruments used, algorthims, etc, they don't go back and update the old data to keep things consistent.

 

The MASIE is based on the IMS data and so is not suitable for comparisons with previous years either. 

 

From the MASIE website:

 

2. When should I use MASIE and when should I use the Sea Ice Index?

 

Use the Sea Ice Index when comparing trends in sea ice over time or when consistency is important. Even then, the monthly, not the daily, Sea Ice Index views should be used to look at trends in sea ice. The Sea Ice Index documentation explains how linear regression is used to say something about trends in ice extent, and what the limitations of that method are. Use MASIE when you want the most accurate view possible of Arctic-wide ice on a given day or through the week. More accurate pictures of ice extent on any given day might be possible on a regional basis and from other international centers. See the IPY Ice Logistics Portal for access. If you have a question about intended and appropriate use of the data, please contact NSIDC User Services.

 

 

 

So when you want consistent data with which you can compare and contrast over different years, you use their sea ice index. The sea ice index is based of passive microwave sensors and is purposely maintained and designed to deliver a consistent version of sea ice coverage since 1978. This is the data that I use when I provide the weekly updates.

You can view the historical dataset here: ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/NH_seaice_extent_final.csv

And the data for this year here: ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/NH_seaice_extent_nrt.csv

 

The sites that are purposely looking at sea ice trends overtime show the same thing.

 

My data (which is similar to the sea ice index mentioned early) shows 2015 to be lower than 2014. The official NSIDC graph shows the same, as does the ADS graph (newer version of IJIS) as does cryosphere today.

 

 

[Nights King]

Has the arctic ice discussion in climate thread been moved? 

[BornFromTheVoid]

Has the arctic ice discussion in climate thread been moved? 

 

Nobody is discussing climate change, but it is the "snow and ice in the northern hemisphere" thread!

[throwoff]

It's like a kids colouring in book gradually getting filled!

 

 

[Methuselah]

Well if we do get anything from Europe, deep and widespread snowcover over Scandinavia cannot be a bad thing. Can it?

Edited November 18, 2015 by Ed Stone

[throwoff]

She grows again.

 

[Midlands Ice Age]

BFTV

 

After ThrowOff  postings as above on the Northern Hemisphere  sea and ice maps, I decided to try and investigate the situation. Particularly as his comments with regard to the ice extents appeared to be correct (from his maps)..

 

First point I noticed is that your charts are referring to Arctic sea ice and from what i would guess are  the 15% sea ice extent figures, whereas Throw off is talking about the northern hemisphere (what concentration?). Is there any difference?

 

The reason is as Throw off suggested the maps he shows don't agree with you hypothesis.There is clearly more ice in the northern hemisphere this year than last.!!!

 

So I went to MAISIE to get the actual ice figures by region.

 

Reproduced here for 2105/11/16 (Day 319) with figures for comparison with last year. Also notice that MAISIE from what I can see is based upon 30% ice coverage. (as compared to NSIDC who in their charts quote  15%). 

 

Also for comparison the NSIDC extent charts are still way below 10 million k squared. (whereas at a greater concentration requirement MAISIE is showing more than this amount of ice).

 

Maisie data -

 

 Area                   Northern Hemisphere           Kara         Barents        Hudson Bay         Greenland      Baffin Bay  Arctic general

2015                   10,465,392                         757,761      98,697           456,282              550,602          795,562      3,173,998

2014                   10,345,368                         879,020      508,175         312,335              469,679          426,417      3,243,450

 

So as you can see, from the last column the general arctic area is running lower this year, mainly due to Kara (120K) and Barents (410K). The other regions though more than outweigh these shortages this year, with Hudson Bay (140K), Greenland sea (80K) and particularly Baffin Bay at (370K).

 

Which seems to tie in more with the charts as supplied by Throwoff above that there is more ice in the northern hemisphere this year than last....

 

So my question(s) to you are 1)  Are your figures based upon 15% or 30%. sea ice concentrations?

2) What areas are included in your charts/ graphs of Arctic sea ice?.

 

Should we be looking at northern hemisphere ice rather than just the Arctic basin for more accurate assessments of sea ice extent.

 

BFTV...

 

Thanks for your response to the above.

 

You have answered my question1 above, but not my point 2..

 

Also the data you supplied on your references for NSIDC  stops at the end of 2014, so doesn't really confirm. But I am not disputing the figures you use.

 

I would like to understand whether Throw offs charts are valid, On checking on Maisie (and DMI) I can see agreement between the observable (ie total northern hemisphere sea ice is greater than 2014). I do accept the within the Arctic circle it is not.

 

So my question to you is what sea areas are covered by NSIDC?. Do they not include Baffin Bay, Hudsons Bay and the Greenland sea?. If not then fine, but why should they not be included?

 

 

 

 

In fact Barents (last year), seems to be the anomaly.

 

Edited November 19, 2015 by Midlands Ice Age

[BornFromTheVoid]

BFTV...

 

Thanks for your response to the above.

 

You have answered my question1 above, but not my point 2..

 

Also the data you supplied on your references for NSIDC  stops at the end of 2014, so doesn't really confirm. But I am not disputing the figures you use.

 

I would like to understand whether Throw offs charts are valid, On checking on Maisie (and DMI) I can see agreement between the observable (ie total northern hemisphere sea ice is greater than 2014). I do accept the within the Arctic circle it is not.

 

So my question to you is what sea areas are covered by NSIDC?. Do they not include Baffin Bay, Hudsons Bay and the Greenland sea?. If not then fine, but why should they not be included?

 

r00_Northern_Hemisphere_ts_4km.png

 

 

 

In fact Barents (last year), seems to be the anomaly.

 

r06_Barents_Sea_ts_4km.png

 

 

The first link I posted previously provides the historical data up to the end of 2014, while the second link contains the data for 2015.

 

The NSIDC passive microwave data includes all the areas you mention. The only difference, I think, is with the small northern lakes. The passive microwave stuff doesn't include them as the spatial resolution of the measurements is too coarse, but they don't make any meaningful difference anyway.

 

As I mentioned earlier MASIE isn't suited to comparing trends or different years with eachother. As for DMI, they show 2014 as higher than 2015 too (through given the thickness of the lines it's tricky to tell).

 

[Midlands Ice Age]

The first link I posted previously provides the historical data up to the end of 2014, while the second link contains the data for 2015.

 

The NSIDC passive microwave data includes all the areas you mention. The only difference, I think, is with the small northern lakes. The passive microwave stuff doesn't include them as the spatial resolution of the measurements is too coarse, but they don't make any meaningful difference anyway.

 

As I mentioned earlier MASIE isn't suited to comparing trends or different years with eachother. As for DMI, they show 2014 as higher than 2015 too (through given the thickness of the lines it's tricky to tell).

 

 

Thanks again BFTV

 

When I looked on DMI 2015 was just above 2014. (now it could be argued either way.)

All of which leaves me even more puzzled.

 

NSIDC (you say are set up for long-term climate change measurements) gives much lower measurements for this year, but looking at the charts supplied by Takeoff and backed up by Maise and DMI ,  they do seem to not agree with NSIDC for the last year and furthermore these  'non-loved' datasets are correct by examination of the charts. To me Maisie is just showing what is out their now!

 

Are NSIDC making the correct adjustments to fit in with old data? Surely they shouldn't be adjusting current data. I do not understand why the regions are so-diverse

Edited November 19, 2015 by Midlands Ice Age

[BornFromTheVoid]

Thanks again BFTV

 

When I looked on DMI 2015 was just above 2014. (now it could be argued either way.)

All of which leaves me even more puzzled.

 

NSIDC (you say are set up for long-term climate change measurements) gives much lower measurements for this year, but looking at the charts supplied by Takeoff and backed up by Maise and DMI ,  they do seem to not agree with NSIDC for the last year and furthermore these  'non-loved' datasets are correct by examination of the charts. To me Maisie is just showing what is out their now!

 

Are NSIDC making the correct adjustments to fit in with old data? Surely they shouldn't be adjusting current data

 

The NSIDC run the MASIE dataset too, the sea ice index and MASIE are made for different purposes, as shown earlier. Given that the NSIDC are kind of the world experts on this stuff, and the sea ice index data agrees with the other main measure of extent and area, I'd trust that they know what they're doing in general.

There will always be subtle differences in the various organisations that create their own extent/area data, due to different instruments, algorithms, land masks, grid cell sizes, etc. As long as the record is consistent, that's what matter if you want to compare different years with each other.

 

The NSIDC website has a very good FAQ sections here http://nsidc.org/arcticseaicenews/faq/

[Midlands Ice Age]

The NSIDC run the MASIE dataset too, the sea ice index and MASIE are made for different purposes, as shown earlier. Given that the NSIDC are kind of the world experts on this stuff, and the sea ice index data agrees with the other main measure of extent and area, I'd trust that they know what they're doing in general.

There will always be subtle differences in the various organisations that create their own extent/area data, due to different instruments, algorithms, land masks, grid cell sizes, etc. As long as the record is consistent, that's what matter if you want to compare different years with each other.

 

The NSIDC website has a very good FAQ sections here http://nsidc.org/arcticseaicenews/faq/

 

Thanks again BFTV. Things are making a bit more sense.

 

I found the following two sections of interest in the Q&A.

 

One - because the daily NCIDC extent is based upon a trailing average of the previous 5 days. Whereas Maisie reports the value for the day unaveraged. Therefore during a rapid period of increase, the NSIDC will probably always behind the daily actual..

 

Why are the daily minimum values that you are currently quoting for past years slightly different than what you originally stated?

 

In April 2012, NSIDC updated its method of calculating daily values for the Arctic sea ice extent minimum from a 5-day centered average to a 5-day trailing average. The new calculations show, for example, that the record minimum occurred on September 18, 2007, which was two days later than we originally reported (September 16). In addition, NSIDC updates extent values, calculated initially with near-real-time data, when final processed data becomes available. These final data, processed at NASA Goddard, use higher quality input source data and include additional quality control measures. The recalculations show a 2007 record low extent of 4.17 million square kilometers (1.61 million square miles). Our originally published value was 4.13 million square kilometers. In the final data, the date of the minimum may also change for some years.

For more information on calculating daily sea ice extent values, see the Sea Ice Index documentation.

 

 

So NSIDC will always be 5 -7 days out of date compared to today's data.

 

 

 

 

 

 

As for Quality Control, the following section is relevant -

 

 

Do your data undergo quality control?

 

The daily and monthly images that we show in Arctic Sea Ice News & Analysis are near-real-time data. Near-real-time data do not receive the rigorous quality control that final sea ice products enjoy, but it allows us to monitor ice conditions as they develop.

Several possible sources of error can affect near-real-time images. Areas near land may show some ice coverage where there isn’t any because a land filter has not yet been applied and the sensor has a coarse resolution. Sometimes, the data we receive have geolocation errors, which could affect where ice appears. Near-real-time data may also have areas of missing data, displayed on the daily map as gray wedges, speckles, or spider web patterns. In addition, satellite sensors occasionally have problems and outages, which can affect the near-real-time data. We correct these problems in the final sea ice products, which replace the near-real-time data in about six months to a year.

Despite its areas of inaccuracy, near-real-time data are still useful for assessing changes in sea ice coverage, particularly when averaged over an entire month. The monthly average image is more accurate than the daily images because weather anomalies and other errors are less likely to affect it. Because of the limitations of near-real-time data, they should be used with caution when seeking to extend a sea ice time series, and should not be used for operational purposes such as navigation.

To look at monthly images that have been through quality control, click on “Archived Data and Images†on the Sea Ice Index.

 

Sure has been made into a complex topic? I notice that they say  not to take any notice of it for real time navigation. It is purely for measurement of  long term averages and can and will be inaccurate for real-time data. I guess that is why they publish Maisie, although I have seen a notice on the Maisie site saying they are under threat of being closed down by NSIDC, and asking for people to write in to show the data is being used!.

Edited November 19, 2015 by Midlands Ice Age

[stewfox]

 

Sure has been made into a complex topic?

 

Not sure why ?, accurate arctic ice measurements particularly thickness is still in its infancy..

 

One can accept general trends wether its DMi. NSIDC MASIE data, I don't like folk comparing current ice levels  to 1880 or 2000BC and its not as robust as the CET series but we have a good handle on it.

[cyclonic happiness]

http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow_asiaeurope.gif

 

 

 

Wow, big gains in Scandinavia over the last few days, must be near record snow cover for the time of years, and it's not even Winter yet :-D

[NorthernRab]

Snow into Hokkaido (Japan's northermost island) now as well I see!

 

I like to think that on one of the various weather forums throughout Europe someone's saying "snow's moved into Scotland too!" in whatever language. 

[marksiwnc]

Denmark snow

http://webcam.trafikken.dk/webcam/Taastrup.jpg

[Gavin Hannah]

Impressive Ice growth towards Iceland and more snow in the UK than on the Alps..... Very interresting.

[Helzmc]

Cracking snow cover in denmark lastnight

[Lincs Observation]

Up to date Ice and Snow 

 

 

[BornFromTheVoid]

The latest weekly Artic sea ice extent update is here https://forum.netweather.tv/topic/74411-arctic-ice-data-and-stats/?p=3289935

[throwoff]

Europe breached big time!