A new online map tracks tropospheric global nitrogen dioxide concentrations—which we’ve seen drop sharply this year as the pandemic shut down economic activity. “This online platform uses data from the Copernicus Sentinel-5P satellite and shows the averaged nitrogen dioxide concentrations across the globe—using a 14-day moving average. Concentrations of short-lived pollutants, such as nitrogen dioxide, are indicators of changes in economic slowdowns and are comparable to changes in emissions. Using a 14 day average eliminates some effects which are caused by short term weather changes and cloud cover. The average gives an overview over the whole time period and therefore reflects trends better than shorter time periods.” [ESA]
The European Space Agency maps the drop in nitrogen dioxide concentrations in the atmosphere in the wake of coronavirus lockdowns in many countries (see above). [GIS Lounge]
Meanwhile, CESBIO researcher Simon Gascoin built a map that compares NO2 concentrations over the last 30 days with the same period in 2019.
Data for these analyses generally come from the Copernicus Programme’s Sentinel-5P satellite. The Copernicus Atmosphere Monitoring Service issued a warning last week about using the data improperly.
Concentrations of NO2 in the atmosphere are highly variable in space and time: they typically vary by one order of magnitude within each day and quite substantially from one day to another because of the variations in emissions (for example the impacts of commuter traffic, weekdays and weekend days) as well as changes in the weather conditions. This is why, even if observations are available on a daily (currently available from satellites) or even hourly (ground-based observations) basis, it is necessary to acquire data for a substantial period of time in order to check that a statistically robust departure from normal conditions has emerged.
Cloud cover is a factor that needs to be taken into account as well.
Previously: Emissions Drop Due to Coronavirus Outbreak.
As you may have seen elsewhere, the coronavirus pandemic is having an impact on air pollution, as countries shut down human and economic activity in an attempt to deal with the outbreak. Take nitrogen dioxide. Tropospheric NO2 density decreased significantly over China between January and February, and the same seems to be happening in northern Italy, which normally has some of the most severe air pollution in Europe. See the ESA’s animation:
Previously: Mapping Nitrogen Dioxide Pollution.
The U.S. National Library of Medicine’s TOXNET, an interactive map that tracked pollution, chemical exposure, toxicology and other data, was shut down last month. The move has been criticized in the context of the Trump administration’s rollback of environmental protections, but the NLM insists that the decision was theirs. The data mapped by TOXNET is available from other sources, but, and this is the point, not as easily or centrally accessible. [The Hill, Newsweek]
NASA Earth Observatory: “The map above depicts changes in water storage on Earth—on the surface, underground, and locked in ice and snow—between 2002 and 2016. Shades of green represent areas where freshwater levels have increased, while browns depict areas where they have been depleted. Data were collected by the GRACE mission, which precisely measured the distance between twin spacecraft as they responded to changes in Earth’s gravity field. In sensing the subtle movements of mass around the planet, the satellites could decipher monthly variations in terrestrial water storage.” The GRACE observations form the basis of a study published this month in Nature on changes in global fresh water availability. More at the JPL’s GRACE-FO project page. [Benjamin Hennig]
Comparing century-old maps of kelp beds in the Pacific Northwest to modern aerial surveys, a University of Chicago professor was able to track the long-term abundance and health of the beds, which in most cases remained remarkably constant: Journal of Ecology article. The kelp bed maps, made from surveys in 1911 and 1912, were the result of U.S. concern about the nation’s potash supply, which in the runup to World War I was largely imported from Germany. The kelp beds were, for some reason, seen as an alternative fertilizer source. That plan never came to fruition, but the maps remained, to be put to use for an entirely different purpose more than a century after they were made. [WMS]
NASA: “Satellites measured land and ocean life from space as early as the 1970s. But it wasn’t until the launch of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) in 1997 that the space agency began what is now a continuous, global view of both land and ocean life. A new animation captures the entirety of this 20-year record, made possible by multiple satellites, compressing a decades-long view of life on Earth into a captivating few minutes.” Here’s a video about it:
Google is using its Street View cars, now equipped with air-quality sensors, to measure air pollution in California on a block-by-block level.
Earlier this year, we shared the first results of this effort with pollution levels throughout the city of Oakland.
We’re just beginning to understand what’s possible with this hyper-local information and today, we’re starting to share some of our findings for the three California regions we’ve mapped: the San Francisco Bay Area, Los Angeles, and California’s Central Valley (the Street View cars drove 100,000 miles, over the course of 4,000 hours to collect this data!) Scientists and air quality specialists can use this information to assist local organizations, governments, and regulators in identifying opportunities to achieve greater air quality improvements and solutions.
The Atlas for the End of the World collects a series of world maps that measure our planet’s environmental well-being. More specifically, they examine the amount of protected area in our planet’s biological hotspots, especially relative to the UN Convention on Biological Diversity’s 2020 conservation targets. Created by landscape architects, the accompanying text (by project lead Richard J. Weller) tends toward the abstruse and verbose, but the maps themselves are quite interesting. (I note that they make extensive use of the Goode homolosine projection, which is refreshing.) [Geo Lounge]
President Trump’s budget proposes eliminating the EPA’s Great Lakes Restoration Initiative. That fact is no doubt what’s behind two publications posting maps earlier this month, only a couple of days apart, showing the environmental stresses on the Great Lakes basin.
Canadian Geographic reposted a map from their July/August 2013 issue:
And the Washington Post included the following map in an article on the proposed elimination of two EPA programs (including the aforementioned Great Lakes Restoration Initiative):
NASA Earth Observatory: “The map above, based on data provided by the National Snow and Ice Data Center, shows the extent of Arctic permafrost. Any rock or soil remaining at or below 0 degrees Celsius (32 degrees Fahrenheit) for two or more years is considered permafrost.” The map differentiates between continuous, discontinuous, sporadic and isolated permafrost. [NASA Earth]
Vox’s lead exposure risk map takes a nationwide look at a crisis some might have thought was limited to Flint, Michigan. “The areas where kids are at highest risk of lead exposure—an estimate calculated using government data about the surroundings—are scattered all across the country.” Lead exposure data is hard to come by, so exposure risk is calculated based on Washington State’s methodology, which uses age of housing and poverty as risk factors. [Mapbox]
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Lake Poopó has become the Aral Sea of the Andes. Thanks to drought, water diversion and mining activity, the lake—long, wide, shallow, saline and the second-largest in Bolivia—has basically dried up, as this comparison of 2013 and 2016 Landsat 8 images demonstrates. CBC News, The Independent.
The European Space Agency has released a map showing the northern hemisphere’s biomass — specifically, its growing stock volume (GSV), which is the amount of wood per hectare in cubic metres. The map is based on radar images taken by the now-defunct Envisat satellite between October 2009 and February 2011.
Previously: Herbal Earth.