Implement ability to load OSTIA sea ice data in pre-processor

[simonrp84]

The data we currently use for sea ice extent is very low resolution (something like 1 degree) and poorly-suited to the pixel size of most imaging instruments. The Operational Sea Surface Temperature and Sea Ice Analysis is at 0.05 degree resolution, so implementing this will reduce the 'blockiness' of retrievals in ice-prone regions.

[caropoulsen]

Sounds interesting What data set is This ECMWF data??

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________________________________ From: Simon Proud <[email protected]> Sent: 01 June 2018 16:03 To: ORAC-CC/orac Cc: Subscribed Subject: [ORAC-CC/orac] Implement ability to load OSTIA sea ice data in pre-processor (#5) The data we currently use for sea ice extent is very low resolution (something like 1 degree) and poorly-suited to the pixel size of most imaging instruments. The Operational Sea Surface Temperature and Sea Ice Analysis is at 0.05 degree resolution, so implementing this will reduce the 'blockiness' of retrievals in ice-prone regions. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub<#5>, or mute the thread<https://github.com/notifications/unsubscribe-auth/Aig_rwZtZ0lNZVID_sYussKSM_DbPqZSks5t4VfEgaJpZM4UW2i9>.

[simonrp84]

No. ECMWF data does contain a sea ice flag (that we can already read if we choose the right driver option) but that is also lower resolution (0.125 degree at best).
Some details about OSTIA are here: http://ghrsst-pp.metoffice.com/pages/latest_analysis/ostia.html

The Nowcasting SAF has implemented OSTIA within their cloud processing and - based on an afternoon of playing around with it - the addition of this product makes a nice difference there. Should be the same for us.

[caropoulsen]

excellent sounds good have you made the changes to the code to include it?

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________________________________ From: Simon Proud <[email protected]> Sent: 01 June 2018 16:10:59 To: ORAC-CC/orac Cc: Poulsen, Caroline (STFC,RAL,RALSP); Comment Subject: Re: [ORAC-CC/orac] Implement ability to load OSTIA sea ice data in pre-processor (#5) No. ECMWF data does contain a sea ice flag (that we can already read if we choose the right driver option) but that is also lower resolution (0.125 degree at best). Some details about OSTIA are here: http://ghrsst-pp.metoffice.com/pages/latest_analysis/ostia.html The Nowcasting SAF has implemented OSTIA within their cloud processing and - based on an afternoon of playing around with it - the addition of this product makes a nice difference there. Should be the same for us. — You are receiving this because you commented. Reply to this email directly, view it on GitHub<#5 (comment)>, or mute the thread<https://github.com/notifications/unsubscribe-auth/Aig_rwNcOiqtZk6ErlbGyu9wGCIMgMVyks5t4VmDgaJpZM4UW2i9>.

[simonrp84]

No, I have not made the changes - this doesn't affect any of my work so it's low priority.
But I thought I'd raise the issue to remind me to look into it if I get some free time. The additions are non-trivial so don't expect it any time soon!

[simonrp84]

As part of this I have now included better snow albedo values, previously these were only defined for 4 wavelengths (0.67, 0.8, 1.6 and 3.9 micron). Now we have 40 wavelengths across VIS and IR. The most suitable albedo is found by interpolating the channel central wavelength to the closest wavelengths in the albedo database. Albedo values are from the ASTER spectral library.

Note: Ice is not included, only snow. Am searching for better ice values.

OSTIA work is still ongoing (slowly).

[simonrp84]

No longer developing new ORAC features, unassigning myself.