CryoSat-2/SMOS Arctic Sea Ice Volume

[Jim Hunt]

I'm not a Python expert, so thanks are due to both Wipneus and Stefan Hendricks for their contribution to the attached source code. Thanks also to Christian for the inspiration.

It converts the gridded merged CryoSat-2/SMOS Arctic sea ice volume data available from the Alfred Wegener Institute into numbers in a CSV file. Here's the data:

ftp://ftpsrv2.awi.de/sea_ice/product/cryosat2_smos/v202/nh/

Here's the AWI manual:

https://spaces.awi.de/display/CS2SMOS/CryoSat-SMOS+Merged+Sea+Ice+Thickness

Here's the source code (rename .txt to .py):

[Jim Hunt]

Here is a rendering of the program's output created in Excel, together with the raw data in a CSV file.

Note that the most recent 2 weeks of data is "near real time". All the rest is "reanalysed".

[Jim Hunt]

Note that Stefan Hendricks has flagged up an "issue" with the CryoSat-2 NRT data:

https://spaces.awi.de/display/SIRAL/2020/02/11/CryoSat-2+-+missing+NRT+data+in+baseline-D

The NRT Level-1 data to the CryoSat-2 sea ice product is missing several orbits, mostly in the Russian Arctic as can be seen in the figure below.

[Jim Hunt]

Another week's data, and the "blip" is gradually disappearing. NRT data starts on January 31st in this graph:

[blumenkraft]

Jim, i think you mentioned it before, but let me ask again, what's the dotted red line? 1SD?

[Jim Hunt]

What's the dotted red line?

It's the "uncertainty" numbers from the CS2 NetCDF gridded data. You'd need to ask Stefan precisely what it represents.

[blumenkraft]

Ah, it makes sense.

Thanks, Jim!

[Jim Hunt]

N.B. I have discovered another "issue" with the AWI merged CryoSat-2/SMOS data, confirmed by Stefan:

https://greatwhitecon.info/2020/07/the-northwest-passage-in-2020/#comment-343435

It looks as though in 2019 the merged product used CS2 data in the CAA, whereas in 2020 it doesn't?

[Jim Hunt]

AWI have recently caught up with the CS2/SMOS version 2.03 reanalysis, and here is the end result:



The data can now be found at:

ftp://ftp.awi.de/sea_ice/product/cryosat2_smos/v203/nh/

[uniquorn]

I'm not a Python expert, so thanks are due to both Wipneus and Stefan Hendricks for their contribution to the attached source code. Thanks also to Christian for the inspiration.

It converts the gridded merged CryoSat-2/SMOS Arctic sea ice volume data available from the Alfred Wegener Institute into numbers in a CSV file. Here's the data:

ftp://ftpsrv2.awi.de/sea_ice/product/cryosat2_smos/v202/nh/

Here's the AWI manual:

https://spaces.awi.de/display/CS2SMOS/CryoSat-SMOS+Merged+Sea+Ice+Thickness

Here's the source code (rename .txt to .py):

Thanks to all for the code, maybe I can make it regional. Here using v205 data from

ftp.awi.de/sea_ice/product/cryosat2_smos/v205/nh/LATEST

for vol, area,extent and avg thickness
will probably have to check these figures

[Jim Hunt]

Maybe I can make it regional.

I look forward to that!

Which reminds me, here's the v205 reanalysis data and a graph also including a few days of autumn 2022 "near real time" data:

[Steven]

From the other thread:

I played around with Jim Hunt's python script and modified it to calculate daily regional volume.  In the calculations, I used the regional mask in the CryoSat auxiliary data (h/t uniquorn):

Thanks very much Steven. Could you upload the modified code to the thread in the Developers Corner?

Hi, attached is the python file to calculate regional volume.  Also attached is the regional mask.  I used python version 3.8.10.

Usage:


1) Save the python file (rename .txt to .py) and the regional mask into the same folder. 

2) Create a subfolder named "data" and copy the CryoSat-SMOS ftp files into that folder.  So the "data" folder will have subfolders "LATEST", "2022", "2021" etc. (or only the ones you need)

3) On the command line, run e.g. the command

python cryosat-smos-regional-volume.py  2021

to calculate the regional volume for all 2021 files.  Or specify a specific filename, e.g.:

python cryosat-smos-regional-volume.py  LATEST  W_XX-ESA,SMOS_CS2,NH_25KM_EASE2_20221219_20221225_o_v205_01_l4sit.nc

[Jim Hunt]

Thanks a lot Steven.

Very useful!