The Dangers of Hurricane Maps’ Cone of Uncertainty

The New York Times

The cone of uncertainty is a core feature of hurricane maps: it shows the potential routes a hurricane is likely to take (the path grows over time, as we’re less certain where the storm goes next). But it’s misinterpreted in ways that put people at risk. That’s the argument made by Alberto Cairo in an online infographic (and in print) in the New York Times last week: research reveals that people living along the edge of the cone are much less likely to prepare for the storm, even though the edge of the cone is one possible path for the centre of the storm—and the cone only covers 60 to 70 percent of the storm’s potential paths in any event.

Alberto Cairo goes into more detail about the problem, and the responsibility of both journalists and readers when faced with such visualizations, on his blog. His book, How Charts Lie: Getting Smarter About Visual Information, comes out from W. W. Norton next month.

Previously: Rethinking the Cone of Uncertainty.

Mapping the Amazon Fires

Let’s start with the current situation map from Brazil’s own space agency, the Instituto Nacional de Pesquisas Espacias (INPE), which I’m surprised is still online. In July Brazil’s president, Jair Bolsonaro, accused the widely respected agency of lying about the scale of deforestation in the Amazon; INPE’s chief, Ricardo Galvão, was forced out earlier this month after defending the agency. After that, INPE said that fires were up 84 percent over the same period last year. (The ESA, for its part, tracked nearly four times as many fires in August as they did last year.)

Other raw data sources include the Copernicus Atmosphere Monitoring Service (CAMS), fire activity data from which can be viewed here; and MODIS data from NASA’s Terra and Aqua satellites. For a live feed of MODIS data on the Amazon fires, see the MODIS Wildfire Dashboard.

NASA

Meanwhile, NASA’s Earth Observatory posted MODIS imagery of several Amazon fires, and had this curious statement that seemed to minimize the scale of the problem: “As of August 16, 2019, an analysis of NASA satellite data indicated that total fire activity across the Amazon basin this year has been close to the average in comparison to the past 15 years. […] Though activity appears to be above average in the states of Amazonas and Rondônia, it has so far appeared below average in Mato Grosso and Pará, according to estimates from the Global Fire Emissions Database, a research project that compiles and analyzes NASA data.”

A subsequent NASA Earth Observatory post seems to contradict the one I mentioned earlier, pointing to “a noticeable increase in large, intense, and persistent fires burning along major roads in the central Brazilian Amazon” which “are more consistent with land clearing than with regional drought” and noted fire detections “higher across the Brazilian Amazon” since 2010.

Contextualizing the amount of fires seems to be a recurring theme in the reporting: the number of fires are up sharply over last year, but close to the average when taking a longer view. It’s helped a lot of bad and insincere actors make it harder to get to the heart of what’s going on over there. They can’t, after all, deny the satellite imagery or the remote sensing: we can see the fires. We can detect the emissions of smoke, carbon dioxide and carbon monoxide (1, 2, 3). We can map them. And those maps can help us understand what’s going on.

On the NGO front, InfoAmazonia has produced the above map comparing fires over the last 24 hours with historical fire data. (They have other maps on this subject as well.)

Note, too, the reference above to burning along major roads. Tim Wallace crunches MODIS date from 2012 onward and teases out some patterns in the fires.

The New York Times

And the New York Times, where Tim used to work, has a map correlating the position of the current Amazon fires along the edges of past deforestation. The Times also has maps showing maps on a month-by-month basis and comparing August 2019 with the August average over the past decade.

[CityLab, Maps Mania]

Map of UV Exposure in the United States

NASA Earth Observatory (Joshua Stevens)

NASA Earth Observatory:

The NASA Applied Sciences Program has partnered with the Centers for Disease Control and Prevention (CDC) to create the first publicly available map of ultraviolet (UV) radiation for all counties in the contiguous United States. The dataset, which spans 2005-2015, is available on the CDC’s National Environmental Public Health Tracking network, which delivers information and data about health issues related to environmental factors. Public health officials, city planners, or individuals concerned about Sun exposure can learn how much ultraviolet radiation is falling over each county each month, which is an important step in helping reduce skin cancer risks.

The animated map above shows the monthly average UV dose in 2015.

Quebec’s Updated Flood Maps Prove Controversial

Government of Quebec (screenshot)

In the wake of serious and devastating spring flooding in 2017 and 2019, the Quebec government issued proposed flood zone maps that marked areas where rebuilding and new construction would be put on hold. There was immediate pushback: as CBC News reported last month, the maps included substantial areas of small towns (such as, in my neck of the woods, the villages of Fort-Coulonge and Campbell’s Bay), or, in the case of Gatineau, areas that were not flooded in either 2017 or 2019 as well as major new developments. The mayor of Vaudreuil-Dorion suggested that the mapmakers forgot to correct for cloud cover. In the end, new maps were issued that removed substantial areas of Montreal from the flood zone, among other areas: some 20 percent of the 120,000 homes affected by the first set of maps were removed from the revised maps.

Previously: Quebec Flood Maps.

Mapping the Flow of Antarctic Ice

UC Irvine/Jeremie Mouginot

This is a map of Antarctic surface ice velocity: the speed at which glaciers flow. It was produced by researchers at the University of California Irvine and the Jet Propulsion Laboratory, using radar interferometry and multiple satellite passes to produce a map 10 times more accurate than previous maps. More: UCI News, Geophysical Research Letters.

Europe’s Heat Wave, as Seen from Orbit

ESA

Europe is in the middle of a severe heat wave. The European Space Agency has released a map of land temperatures in Europe as of 26 June, produced from the Copernicus Sentinel-3 satellite’s temperature radiometer, “which measures energy radiating from Earth’s surface in nine spectral bands—the map therefore represents temperature of the land surface, not air temperature which is normally used in forecasts. The white areas in the image are where cloud obscured readings of land temperature and the light blue patches are either low temperatures at the top of cloud or snow-covered areas.”

New Map of Greenland and the European Arctic

British Antarctic Survey

The British Antarctic Survey—which despite its name focuses its attention on both polar regions—has released a new one-sheet map of Greenland and the European Arctic. The 1:4,000,000-scale map covers a region from Baffin Island to Novaya Zemlya to Scotland: a region that’s usually on the edges of maps of the Arctic and Europe rather than getting its own map. More importantly, it’s a very recent snapshot of a rapidly changing region: the retreating ice sheet in Greenland is revealing new landscapes. The map costs £12 and is available either folded or rolled from Stanfords and the Scott Polar Research Institute. [BBC]

Quebec Flood Maps

In my neck of the woods we’ve been dealing with some pretty severe spring flooding. And as is often the case, existing flood maps are not up to handling the new normal imposed by climate change. Sainte-Marthe-sur-le-Lac, a community near Montreal, was hit hard by flooding this spring, but only two of the 800 flooded homes were in current maps’ flood zones. This isn’t an new situation; we had similar floods in 2017. Back then, CBC News reported that Montreal-area flood maps’ 20- and 100-year floodplains were exceeded by the then-current flood extent.

Fast forward to this spring. The flood maps for Montreal-area municipalities have been updated—they’re now based on LIDAR data from 2014 onward—but have not yet made public: they’ve yet to be approved by the municipalities or adopted by the province; nonetheless they’ve been put to use during the recent emergency. On the new maps, some 1,500 homes in Sainte-Marthe are part of the flood zone.

Mapping Disasters in America

The Washington Post maps disasters in the United States, with a page that shows maps of flood warnings, tornadoes and hurricanes, extreme heat and cold (see above), wildfires, lightning, and earthquakes and volcanoes. In the wake of a natural disaster there’s usually someone suggesting that the victims are at fault for living in a disaster zone. The WaPost’s maps have an answer to that: “It turns out there is nowhere in the United States that is particularly insulated from everything.”

The Earth’s Climate Zones Are Shifting

Climate change is redrawing the map, writes Nicola Jones in a piece for Yale Environment 360 last October. It’s not just about polar ice caps, she writes: “Sometimes, the lines on the map can literally be redrawn: the line of where wheat will grow, or where tornadoes tend to form, where deserts end, where the frozen ground thaws, and even where the boundaries of the tropics lie.” Her article is punctuated by maps showing the changes in Earth’s climate zones, some of which dramatically and in a short period of time.

The Polar Vortex, Visualized

NASA Earth Observatory maps the bitterly cold temperatures resulting from cold air pushed southwards by an unstable polar vortex. The maps and animations are by Earth Observatory’s lead cartographer, Joshua Stevens. On Twitter he posted a companion visualization showing what’s happening on the other side of the planet, where a searing heat wave is blistering Australia.

California Wildfire Roundup

San Francisco Chronicle (screenshot)

The San Francisco Chronicle’s 2018 California Fire Tracker is an interactive map of ongoing and contained wildfires—notably, at this moment, the Camp and Woolsey fires. It includes fire perimeter and air quality data. (Note: it’s glitchy on desktop Safari.)

Two Esri maps: a general wildfire map and a map of smoke from wildfires [Maps Mania]. Add to that a map of field damage reports in the area hit by the Camp Fire [Maps Mania].

NASA/JPL-Caltech

The Jet Propulsion Laboratory has produced a map of the damage from the Camp Fire based on satellite radar images. NASA Earth Observatory has maps and animations showing the impact of the Camp Fire on air quality and satellite images of the Woolsey Fire burn scar.

NOAA

The New York Times has a map tracking air quality in California. Smoke from the fires has reached the east coast: an outcome predicted by atmospheric models (see above map).

This interactive map from NBC News that superimposes the Camp Fire on any location to help people outside California get a sense of how big these fires are. [Maps Mania]

Rethinking the Cone of Uncertainty

A feature of hurricane maps is the so-called cone of uncertainty, which shows the range of likely paths the hurricane is forecasted to follow. The problem is that the cone of uncertainty is easily misinterpreted by the reader. The MIT Technology Review’s Karen Hao looks at five ways the cone can be misinterpreted, along with some alternative methods of visualizing a hurricane’s projected path. [Gretchen Peterson]

Hurricane Michael’s Impact

It’s after the fact, at least in terms of initial landfall (if not aftermath), but maps I’ve seen of Hurricane Michael include the USGS’s Hurricane Michael page, which includes an event support map and a map of coastal change impacts; and imagery from the Suomi NPP satellite that shows the path of Hurricane Michael through the power outages left in the storm’s wake.