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More Glaciers CCI Use Cases

Norman Fomferra edited this page Jan 11, 2018 · 5 revisions

From Frank (Mail from 20.12.2017):

See also Vector-Data-and-FATs and #477.

Operations

On a very basic level Cate needs to know where a glacier is (point coordinates in lon/lat) and then be able to extract for this point time-series of other ECVs (e.g. cloud cover). This is likely very easy to implement and would be super cool.

More advanced operations might need to perform database queries, e.g. show me in Cate where the largest glacier is (e.g. on Earth, in Europe, in the Alps) and then show me how it has changed in the past (requires link to FoG database) and create a plot of the time series (could be length changes since 1870).

If this glacier has no fluctuation data, show me in Cate where the nearest glacier is that has a time series and is larger than xx km2 (this requires that the glaciers in the FoG database also have x/y coordinates and Cate knows where they are).

So basic operations are distance operations (on a sphere), database queries that search for largest/smallest entries, maybe filtered by other attributes (e.g. the region or country), and connections between two databases based on locations.

Visualisation

As mentioned before, there is maybe no need to draw the complete outline in Cate but just represent a glacier by a symbol at its coordinates. Showing also outlines can maybe be implemented at a certain level of magnification, e.g. when the width of the area shown is <100 km or larger than a certain zoom factor (see also http://www.wgms.ch/fogbrowser/, where point clustering is used). We then need the possibility to overlay other ECV datasets to navigate through spatial patterns and then time series plots (x,y) with lines and maybe bar charts.

The shape files of the glacier outlines are available from http://www.glims.org/RGI/rgi60_dl.html (maybe just download Central Europe) the latest FoG dataset from WGMS (http://wgms.ch/data_databaseversions/) is available here: http://dx.doi.org/10.5904/wgms-fog-2017-10. All datasets should finally be also available in the CCI ODP (but are not yet). As they are not very large (MB), it might be helpful for all operations to download them directly into the 'datasets folder' of the respective Cate user.