cliwoc test

Six months ago I posted on CLIWOC ship location data, and last month the complete historic weather superset focusing on ArcGIS Online (AGOL). Why? Because when wind force and direction data are joined to four look-up tables from each maritime agency involved, a 1/4M point dataset balloons to 1/2M points*! So  to reduce web data fetches, time-slider is used to step through the data be decade.

*: asked on my blog why that may be so, that drew an interesting answer posted as an addendum  

Mapcentia does not offer time awareness out-of-the-box yet, but just released the ability to post zipped shape files: thus a 1Gb file zipped to 30Mb and loaded pronto, far better than geoJSON preferred for interoperability that ballooned files written in plain text.  I had not subsetted the weather data into time spans, like the location data in quarter centuries. So I loaded the entire data set, and created views for each decade - Mapcentia's Martin Hogh assured me that postGIS could handle a gigabyte dataset, as indeed giscloud.com did too but sadly without the ability to orient symbols yet.

1. the entire dataset posts online in a flash... faster than on ArcGIS or QGIS desktop in fact!
2. this allowed to post the wind data in decade slices, by simply creating views to the above

So Mapcentia's cool styling also recently updated, helped post the datasets scaled and coloured by wind force (Beaufort scale) and oriented by wind direction. Stepping through the decades offers an arresting insight into wind data from 1740- 1860 (1660-1670 turned out ot be sample dataset, with no  data until 1740).

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Note also that in addition to that, a full complement of weather attributes recorded in the ships captains logs is available, and can be loaded and styled by climate experts.  

I posted the gazetteer data as an example of further historic data available in this amazing CLIWOC data sets. Isn't it fascinating to explore the historic places, recorded with modern names for ease of use?

  Click to see map in new window