Saturday, 13 July 2019

Community, climate and maps (updated)

[Update1: Northwest Passage: Maps and words adds more illustrations and better maps
Update2: see also this video Arctic Sea Ice Summer based on improved maps above
Update 3: further story map Fire & Ice - Arctic past and future climes focused onshore]

You know you're onto something when your activities converge like so:
  • ever since geologising in the Arctic 30 yrs ago, about the time of initial finds of Franklin lost expedition by Owen Beattie
  • finding out while up there that there was a cat&mouse game between Americans and Canadians over the Northwest Passage
  • recently mapping historic tall ships climate data, as a complement to more recent & land based data, now that it's absolutely critical we better understand climate dynamics
  • using a sea-level rise map resulting from polar ice melts to raise awareness of the climate emergency at a recent Extinction Rebellion event in my hometown

In creating story maps for my last post and seeking to tie in sea level rise with polar ice melt, it emerged that sea ice extents had been mapped since 1978 and are still being mapped an posted as part of Esri Living Atlas datasets on ArcGIS Online! In addition they and Esri Canada posted polar and  Northwest Passage sea routes, and from the previous project I added EEZ (Exclusive Economic Zone ) and WPI (World Port index) data: They provide a framework of the infrastructure affected by sea ice extents. So go to this web map and see for yourself if Arctic Sea Ice has shrunk enough to open the Northwest Passage?

Update: notwithstanding the update notices atop this post, I quickly redid the maps in ArcGIS Pro using US govt. source data only.  No matter how good Arcgis Online is, desktop apps simply allow better access to available online data: I created the following using source data only, with no additional processing!

Press the arrow to launch the animation, and see how the light grey winter maximum sea ice extents vary somewhat, but only shrink after 2015. This sea ice extents reduction is real but unspectacular.



Zoom in the map above to the Canadian Arctic, say, between Thule and Inuvik - zoomed in source web map for this web app is here and a package (requires Esri) in Canadian projection is here - these show the tan sea ice extents in the summer months of least extent, and thus highest likelihood of open passage. Note that  in 1986 the entire archipelago is ice bound, after that oscillation are pretty constant thru 2015, then a sharp decrease in sea ice extent in 2016-17, and a slight increase 2018-19 (see update at bottom).

Note that, from details in the source map, these monthly averages describe past until near-present state, and not the future state. These are also general trends based on satellite imagery, localised trends will vary and always complement it with ground truthing. Also further details on polar ice melt and geological framework is here.

Russell Potter noted in Facebook Group Remembering Franklin ExpeditionShrinkage in overall volume doesn't mean increased navigability. Last summer was a median low, but not a single ship made it through the Passage. I'll let everyone know how this year goes (see comment above on ground truthing). His blog Visions of the North has more on his Arctic travels and topics.
This is a further example of helping citizen science, using simple tools that help aggregate relevant data, in order to help you ascertain the hard facts on climate change and global infrastructure.
Stop presses: here's an onshore story to complement this one, also in the story map: Fire and Ice, atop this post:


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