Also from last week: someone on Facebook circulated a map showing the path of Hurricane Irma hitting Houston, prompting the National Weather Service to issue a warning on Twitter about fake forecasts (real forecasts only go out five days). Media factchecking service PolitiFact has the details. Fun fact: making a counterfeit or false weather forecast is an offense in the United States.
Category: Weather and Climate
Mapping Hurricane Harvey’s Impact
The Washington Post maps rainfall and flooding levels in the Houston area.
The New York Times is collecting several maps on two web pages. The first page deals with subjects like rainfall, river level, current and historical hurricane tracks, damage reports, and cities and counties under evacuation orders. Maps on the second page look at Harvey’s impact on the Houston area.
Esri’s U.S. Flooding Public Information Map includes precipitation and flood warnings.
#Harvey in perspective. So much rain has fallen, we've had to update the color charts on our graphics in order to effectively map it. pic.twitter.com/Su7x2K1uuz
— National Weather Service (@NWS) August 28, 2017
Kenneth Field critiques the National Weather Service’s decision to add more colours to their precipitation maps (see above). “Simply adding colours to the end of an already poor colour scheme and then making the class representing the largest magnitude the very lightest colour is weak symbology. But then, they’ve already used all the colours of the rainbow so they’re out of options!”
Extreme Event Attribution
Whenever a cataclysmic weather event occurs—like Hurricane Harvey right now—there’s usually a heated political argument over whether or not it can be blamed on climate change. It turns out that there’s a field of research dedicated to assessing whether extreme weather can be attributed to climate change: it’s called extreme event attribution. There have been more than 140 peer-reviewed attribution studies of extreme weather events around the globe, which Carbon Brief has mapped here.
Carbon Brief’s analysis suggests 63% of all extreme weather events studied to date were made more likely or more severe by human-caused climate change. Heatwaves account for nearly half of such events (46%), droughts make up 21% and heavy rainfall or floods account for 14%.
FEMA Flood Maps Don’t Account for Future Sea Level Rise
NPR last month, reporting on a problem with FEMA’s flood insurance maps: they’re not keeping up with reality. “FEMA’s insurance maps are based on past patterns of flooding. Future sea level rise—which is expected to create new, bigger flood zones—is not factored in. So some communities are doing the mapping themselves. Like Annapolis, the state capital of Maryland.” [Leventhal]
NASA Images of Hurricane Harvey
NASA’s page on Hurricane Harvey has been updated many times, sometimes several times a day, since Harvey began its life as Tropical Depression 9 on 17 August. It includes plenty of satellite imagery of the storm, as well as temperature and rainfall maps.
Emil Letoschek’s Weather Map
Federerico Italiano unearths a scarily abstract 1888 weather map of Europe by Emil Letoschek that is nevertheless intelligible (at least if you read German).
CBS Boston on the BPL’s Weather Maps Exhibit
CBS Boston has more on the Boston Public Library’s exhibit, Regions and Seasons: Mapping Climate Through History (previously).
Mapping Global Landslide Susceptibility
NASA Earth Observatory notes the release of a new map of global landslide susceptibility that models the risks of landslides that are triggered by heavy rain. “The map is part of a broader effort to establish a hazards monitoring system that combines satellite observations of rainfall from the Global Precipitation Measurement (GPM) mission with an assessment of the underlying susceptibility of terrain.” [Geographical]
Iceberg Finder
Iceberg Finder tracks icebergs around Newfoundland and Labrador, based on satellite imagery and on-the-ground (so to speak) reporting. It’s a project of Newfoundland and Labrador Tourism, which suggests that the bergs are seen more as tourist attractions than hazards to navigation.
Regions and Seasons
A new exhibition at the Boston Public Library’s Leventhal Map Center: Regions and Seasons: Mapping Climate Through History. “In this exhibition, you will discover how ‘Venti’ were wind personas who directed ancient ships and ‘Horae’ were goddesses of the seasons who dictated natural order during the 15th-17th centuries, how Enlightenment scientists started to collect and map weather data, and how 19th century geographers reflecting the golden age of thematic cartography created innovative techniques to represent vast amounts of statistical data and developed complex maps furthering our understanding of climatic regions.” Runs through August 27; also online.
Mapping Arctic Warming
At All Over the Map, Betsy Mason posts 11 Ways to See How Climate Change Is Imperilling the Arctic, a collection of maps and infographics depicting several different indicators of global warming, including sea ice extent, atmospheric temperatures, growing season, polar bear populations, as well as projected shipping routes for an ice-free Arctic Ocean.
Meanwhile, NASA Earth Observatory points—while it still can—to a study mapping the extent of existing and potential thermokarst (thawed permafrost) landscapes. On the Earth Observatory maps (see North America, above), “[t]he different colors reflect the types of landscapes—wetlands, lakes, hillslopes, etc.—where thermokarst is likely to be found today and where it is most likely to form in the future.”
Previously: Mapping Arctic Sea Ice; Mapping the Thaw.
NOAA’s White Christmas
NOAA maps the probability of a white Christmas across the lower 48 states: the interactive version includes clickable locations.
While the map shows the historical probability that a snow depth of at least one inch will be observed on December 25, the actual conditions in any year may vary widely from these because the weather patterns present will determine the snow on the ground or snowfall on Christmas day. These probabilities are useful as a guide only to show where snow on the ground is more likely.
While the subject may seem whimsical, it’s based on 1981-2010 Climate Normals data; this paper details into the methodology involved. (It also answers a question that climatologists and meterologists get a lot.)
November Sea Ice
NASA Earth Observatory: “In November, the sea ice extent averaged 9.08 million square kilometers (3.52 million square miles)—the lowest November extent in the satellite record. The yellow line shows the median extent from 1981 to 2010, and gives an idea of how conditions this November strayed from the norm.” Also shows sea ice extent for previous years dating back to 1978. Hudson Bay was icebound in November not that long ago.
Previously: Mapping Arctic Sea Ice.
Mapping Arctic Sea Ice
Something’s going on in the Arctic. As the Washington Post reported last month, the Arctic Ocean was far, far warmer than normal—about 20 degrees Celsius higher than average. (Meanwhile, the air over Sibera is at record cold levels.) According to the Post, the higher temperatures are the result of record low amounts of thinning sea ice, as well as warm air being brought north by an increasingly errant jet stream.
NASA has been tracking sea ice levels and thickness by looking at the age of the ice in the sea ice cap. The video above shows “how Arctic sea ice has been growing and shrinking, spinning, melting in place, and drifting out of the Arctic for the past three decades. The age of the ice is represented in shades of blue-gray to white, with the brightest whites representing the oldest ice.”
The ESA reports that their CryoSat satellite “has found that the Arctic has one of the lowest volumes of sea ice of any November, matching record lows in 2011 and 2012.” The animated GIF below shows the change in November sea ice from 2011 to 2016, as observed by CryoSat.
Hazard Maps of Yukon Communities
Several Yukon communities are built on permafrost. In the context of climate change, that’s something of a problem. CBC News reports on a six-year research project that has produced hazard maps of seven Yukon communities; the maps evaluate the risk to future development from permafrost melting, flooding and ground instability. [CCA]