Arctic Penguin (Wipneus) data files contain "nan" values

[Alphabet Hotel]

I downloaded the file nsidc_arc_nt_detail.txt from the Arctic Penguin site and I've been loading it into a database. I just ran into a problem converting some of the values into numbers: 43 rows contain the string "     nan" instead of numbers ("nan" means "not a number"?) I guess I can just convert these into nulls (or drop these rows entirely) but is the data really unavailable?

$ grep nan nsidc_arc_nt_detail.txt | tail -3
1988-01-12 12:00,  12.00,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan
2021-02-20 12:00,  51.75,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan
2021-02-21 12:00,  52.75,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan,     nan

[oren]

You can write a PM to Wipneus to make sure, but I think these are dates with no available data.

[oren]

The images say no data - but there is an update of the spreadsheets.
With some hesitation - here is the update with data to 22nd Feb

Better yet, check the NSIDC files directly, maybe the data exists there. Feb 20-21 this year was an outage but maybe they restored the data later.

[oren]

This is my most recent link for the NSIDC files, but IIRC you need some ftp software now to download. This is for the regional file but I assume the ftp directory has all the other files as well.

ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/seaice_analysis/Sea_Ice_Index_Regional_Daily_Data_G02135_v3.0.xlsx

[SimonF92]

Also, dont drop the rows as this could lead to index mismatching..Nans will help keep the data in the correct shape. Most commonly used data interpretation tools can handle nans.

[Alphabet Hotel]

Also, dont drop the rows as this could lead to index mismatching..Nans will help keep the data in the correct shape. Most commonly used data interpretation tools can handle nans.

SQL wants nulls, but otherwise I see what you mean. I'll keep the empty values.

[gerontocrat]

I downloaded the file nsidc_arc_nt_detail.txt from the Arctic Penguin site and I've been loading it into a database. I just ran into a problem converting some of the values into numbers: 43 rows contain the string "     nan" instead of numbers ("nan" means "not a number"?) I guess I can just convert these into nulls (or drop these rows entirely) but is the data really unavailable?

is the data really unavailable? Yes. I believe there was a problem with the satellites and took a long time for NSIDC to sort out. Change of satellite and recalibration for consistent data?

ps: Wipneus uses a diffrent map from NSIDC to define the boundaries of the central arctic seas. This affects the CAB, the Beaufort, the Chukchi the ESS, the Laptev, and to a lesser extent the Kara and CAA.

[gerontocrat]

This is my most recent link for the NSIDC files, but IIRC you need some ftp software now to download. This is for the regional file but I assume the ftp directory has all the other files as well.

ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/seaice_analysis/Sea_Ice_Index_Regional_Daily_Data_G02135_v3.0.xlsx

I have found that if using Google I go to https://nsidc.org/arcticseaicenews/sea-ice-tools/ and then scroll down to the list of files all I need to do is click on the files(s) I want and they download without a problem. A few months ago it didn't work anymore but now it does.

The other way is to copy that ftp address directly into Windows Explorer (not Internet Explorer) and hit enter. The file list comes up, choose your files, right click and choose copy to folder. It works though Microsoft say they have dumped supporting ftp.

[oren]

I suggest to edit the first post title to:
Arctic Penguin (Wipneus) data files contain "nan" values

This will help others in the future who encounter the same issue.

[kassy]

Done.