[MASK]: Randolph Glacier Inventory (RGI)

[fmaussion]

Overview

• Product name and version: RGI v7 (applies to previous versions)
• Purpose of your product: Reference product for glacier outlines outside of the ice-sheets (modelling, remote sensing...)
• Geographic region: Global, peripheral

Doc: https://www.glims.org/rgi_user_guide

Upstream

• What upstream mask product did you use?

The input data comes from optical imagery, mostly Landsat. No other mask is used, unless the outlines authors did.

In Greenland, RGI uses Raster et al (2012). From the paper its not clear what / if they used a mask for the ice sheet proper to help their connectivity level design.

In Antarctica, RGI uses Bliss et al., (2013), which itself relies on the Antarctic Digital Database quite heavily. RGI7 corrected quite some geometries for poor georeferencing.

ADD Consortium (2000) Antarctic Digital Database, Version 3.0, database, manual and bibliography. Scientific Committee on Antarctic Research, Cambridge
Bliss, A., Hock, R., and Cogley, J.G. A new inventory of mountain glaciers and ice caps for the Antarctic periphery. Annals of Glaciology, 54(63):191–199, jul 2013. https://doi.org/10.3189/2013AoG63A377.
Rastner, P., Bolch, T., Mölg, N., Machguth, H., Le Bris, R., and Paul, F.: The first complete inventory of the local glaciers and ice caps on Greenland, The Cryosphere, 6, 1483–1495, https://doi.org/10.5194/tc-6-1483-2012, 2012.

• Reason for using this mask

These two papers (2012 and 2013, mind!) decided to do so. Raster suggests a definition, Bliss also contains arguments as to why certain outlines were chosen to be "peripheral" or not.

• If you modified the upstream mask, for example, to define and split ‘main’ vs. ‘peripheral’, how and why?

It would be based on a discussion happening here, and together with a clear definition of "main".

• Effort required by you if upstream product changed (to a community standard)

If its just about removing outlines, RGI could be amended very quickly. The redefinition of a new standard has, however, quite important implications for downstream products. It's also very likely some sort of mapping would be needed.

• If you used internal basins, which product and why?

N.A.

• If you subset to a geographical region (Greenland, Antarctica, sub-region, peripheral, individual glacier), how and why

N.A.

• Type: vector, raster

Vector

• Resolution if raster:

N.A.

• Projection information: [Example: WKT string, proj4 string, EPSG code, or other]

WGS84

Downstream

The two original inventories have been slightly adapted for RGI. Importantly, connectivity level 2 is filtered out in Greenland. The main rationale for picking the masks in Bliss and Rastner remains valid.

Other notes