Global Air Pollution, From Above

neutron_p writes "Based on satellite observations, the high-resolution global atmospheric map of nitrogen dioxide pollution makes clear just how human activities impact air quality. I'm a bit surprised not to see that many red blobs above US and the strange one is on the east of Russia."

Comments

night map

[Coneasfast]

note how the red areas are somewhat similar to the light areas on the nasa night map

Russia?

[Zocalo]

Um, no, that's largely China and maybe the Korean peninsula, although it does extend far enough to the North to encompass Vladivostok I think. Still, I suppose they have a better excuse than we do here Europe... That big red blob is mainly over the lowlands of Holland and surrounding areas, so it's either tulips or the output from the "coffee" shops of Amsterdam. I'm thinking it's probably not the tulips. ;)

Re:Take note

[krlynch]

This doesn't actually impact NO2 levels, but it does explain some of the pollution reduction.

The primary reason that you don't see this type of pollution in the US is that the federal and local governments have taken a very agressive stance on NOx and SOx reduction from transportation (cars, trucks, and trains) and power plant (coal) sources. Some here have complained that the attack on these pollutants (along with particulate emission) has a lot to do with our lower fuel economy standards, as the rules make it pretty difficult, for instance, to introduce diesel powered cars, and they mandate the use of catalytic converters.

It isn't hard to understand why this has happened, either. NOx and SOx are the primary drivers of acid rain and smog, both of which directly and visibly impact quality of life in densely populated areas, like cities. Fixing them isn't something we have fought against, since the vast majority of Americans work and live in or near major cities, even in the "sparsely populated" parts of the country.

Western Europe on the other hand has chosen to go after consumption, and driven up fuel efficiency at the cost of reducing these types of pollutants. Given that Europeans tend to live in smaller, more distributed communities than Americans, smog, while a problem in Urban areas, directly impacts fewer people on a day to day basis than it does here.

validity of the study

[theMerovingian]

This looks like a relatively professional study: the maps on the website are a composite of 18 months worth of data. This is good methodology to ensure that anomalies are removed (unusual smog days, lightnings storms, etc).

This map is a measure of the vertical density of NO2 in a given column (represented by the area of each pixel on the original image, which is dependant on the camera).

One misleading thing: There is no mention of the climatological effects of the world's mountain ranges, and thus the prevailing winds. This is clearly illustrated along the Himilayas in India and the Andes mountains in South America. The topography is clearly causing bottlenecks in the distribution and dispersion of air. Thus, the map is not necessarily an indicator of where the actual pollution was produced. Naturally, in locations where airflow is reduced, the vertical profile of ANY gas concentration will be higher.

I'd predict you'll even see some similar patterns in global precipitation maps if you were to overlay the two.

(disclaimer: yes I am a prefessional geographer)