Historic climate data revisited - 3 - circum-Arctic update

[Update: Part 4 provides a further update on platforms available to map polar data]

In my previous blog, how many layers can be combined in an arresting polar Arctic view. They show the almost zero overlap of historic and current weather and climatic data. They herald the importance of oceanic climate data going back before 1880, when any weather data get scarce.

Simon Kettle pointed out to me the World Port Index data he added to the ESRI Living Atlas layers - 3,400 and counting! - which I promptly added to my ArcGIS Online map. How do they compare to the CLIWOC gazetteer locations of 18th - 19th c. ports?

Click to enlarge

Shown below with the EEZ (Extended Economic Zones) you will notice that there are:

• understandably a lot more ports (colour by size) recorded recently
• more curiously there are many old ports unregistered (black&white boat symbol)

Click ot enlarge

Especially in Spitsbergen, N Scotland and Hudson Bay, predominalty old ports reflect a decrease in maritime commerce and activity over history. On the other hand in Alaska, Greenland  and Iceland one sees a marked increase in the number of ports. This interesting dataset bears further investigating into maritime logistics and history .

Here is yet another dataset of historic interest - maritime commerce this time - that compares&contrasts activity over the past centuries. Open data really works!