Citizen science vs. MODIS on producing maps of atmospheric dust

Measurements by thousands of citizen scientists in the Netherlands using their smartphones and the iSPEX add-on are delivering accurate data on dust particles in the atmosphere that add valuable information to professional measurements. The iSPEX team, led by Frans Snik of Leiden University, analyzed all measurements from three days in 2013 and combined them into unique maps of dust particles above the Netherlands. The results match and sometimes even exceed those of ground-based measurement networks and satellite instruments. Here is the comparison of the maps produced by citizen science versus MODIS:

iSPEX map compiled from all iSPEX measurements performed in the Netherlands on July 8, 2013, between 14:00 and 21:00. Each blue dot represents one of the 6007 measurements that were submitted on that day. At each location on the map, the 50 nearest iSPEX measurements were averaged and converted to Aerosol Optical Thickness, a measure for the total amount of atmospheric particles. This map can be compared to the AOT data from the MODIS Aqua satellite, which flew over the Netherlands at 16:12 local time. The relatively high AOT values were caused by smoke clouds from forest fires in North America, which were blown over the Netherlands at an altitude of 2-4 km. In the course of the day, winds from the North brought clearer air to the northern provinces.

Read more at: http://phys.org/news/2014-10-citizen-science-network-accurate-atmospheric.html#jCp

Cool cartography--Risk mapping at a broad view

I came across this short blurb by  on some tricks for catchy large-scale maps. The bullet-points include:

• Interesting Topic.  The subjects of these maps inherently represent risk, which we want to understand.
• Unexpected Scope.  A forest view of something that’s usually seen at the tree-level offers satisfying perspective.
• Big and Clear.  A single dataset is conceptually simple, and when large enough, it provides its own context-promoting conversation in the wild.
• Sharable.  A static image is portable and paste-able, easily nestling into articles, blogs, tweets, and PowerPoints.
• Attractive.  The currency of design buys a second or third look.

There is often a push to make large datasets available through interactive webGIS portals, but I think this makes a good case that there is still also a role for skilled cartography to present information in captivating ways. 

Below is an example of one of the author's (John Nelson) maps, and more can be found here. 

Ghost Maps

There are over 35 million geotagged, time-stamped photos on flickr now. That's enough to start doing some pretty interesting analyses, including this one from Crandall, et al., at Cornell (presented at the WWW 2009 conference, "Mapping the World's Photos" [PDF]).  Not only is it possible to map hot spots of world tourism, but by incorporating the time stamps to map the routes people are taking, you can make out individual streets. As suggested by the Information Aesthetics blog, you could even design popular walking tours.

Once GPS-enabled cameras represent a larger share of the market, flickr may provide data for all sorts of important analyses: tracking SOD, the migration of an endangered song bird, or estimating the "desolation" of a place: the world heat map that the Cornell group presents looks shockingly like the lights at night. The machine... it's ALIVE!!!