Night Light Maps Open Up New Applications

Much has been written lately in the popular press regarding the new set of satellite images released by NASA showing Earth at Night. Few sources provide a clearer view of human settlement patterns contrasting heavily populated and industrialized areas with those less populated and/or less “plugged in”; while Europe and eastern North America gleam, much of Africa is dark despite its high population, although the Nile Valley and Delta sure stand out.

I particularly like the Earth at Night images for illustrating settlement patterns across Canada: high concentrations show up as the urban archipelago across the nation; there are regular, evenly-dispersed populations across the plainsfarmland of southwestern Ontario and, of course, the Prairies; mountain valleys in the west clearly show linear patterns as do the coastal margins of the Martimes and St. Lawrence and along with rail and road corridors across northern Ontario, while much of the rest of the Canadian Shield is dark except for randomly dispersed mining and logging settlements and First Nations’ communities.

I highly recommend spending a few minutes reading this article by the Earth Observatory, as it provides an insightful glimpse of the tech behind these wonderful images – ideal for anyone pursuing remote sensing.


Mountains, clouds and relief precipitation

CroatiaHere in Canada, we are very familiar with how the Coast Mountains of BC influence the precipitation patterns of places along the west coast like Vancouver, Tofino and Ucluelet. It’s a classic case of moist, west winds from the Pacific being forced upwards by the mountains to cool, condense, form clouds and precipitate (CCCP* to my students) providing in excess of 3000mm of precipitation along the coast.

So, it’s interesting to see a similar but quite different phenomenon occurring in Croatia as shown by this NASA Earth Observatory Image-of-the-Day. Instead of west winds from the sea (the Mediterranean, intros case), they are easterlies, so that the moisture is “dumped” on the east side of the coastal range as shown by the cloud.

Have a look at the NASA EO IOTD page for a more thorough treatment of this: Of Mountains and Moisture.

* Of course, CCCP is only significant to old farts like me who remember the USSR and, in my case, their hockey jerseys emblazoned with CCCP. It does make for a good hockey story for my students, though. A little history mixed in with Geography never hurts.