Hot and Cold

NASA Earth Observatory map by Jesse Allen based on MODIS data

The deep freeze is unevenly distributed. NASA Earth Observatory published this temperature anomaly map based on data from the MODIS instrument on NASA’s Terra satellite. A temperature anomaly map shows how much warmer or colder temperatures are versus the average—in this case, land surface temperatures from 26 December 2017 to 2 January 2018 are compared to the 2001-2010 average for the same period. While it’s awfully cold in Canada, and the central and eastern United States, it’s warmer than normal in the southwest. And if you look beyond the North American continent (which is something people should do more often), it’s generally warmer worldwide, particularly in Europe and Asia:

NASA Earth Observatory map by Jesse Allen based on MODIS data

Hurricanes and Aerosols

NASA Goddard

NASA’s Goddard Space Flight Center produced this visualization, based on computer modelling and data from Earth observing satellites, tracking how hurricanes transport sea salt, dust, and smoke across the globe.

During the 2017 hurricane season, the storms are visible because of the sea salt that is captured by the storms. Strong winds at the surface lift the sea salt into the atmosphere and the particles are incorporated into the storm. Hurricane Irma is the first big storm that spawns off the coast of Africa. As the storm spins up, the Saharan dust is absorbed in cloud droplets and washed out of the storm as rain. This process happens with most of the storms, except for Hurricane Ophelia. Forming more northward than most storms, Ophelia traveled to the east picking up dust from the Sahara and smoke from large fires in Portugal. Retaining its tropical storm state farther northward than any system in the Atlantic, Ophelia carried the smoke and dust into Ireland and the UK.

Video at the link, or here’s the YouTube version. [APOD/Kottke]

British Antarctic Survey Remeasures Mount Hope

Mount Hope, 18 March 2004. Photo by Euphro. Creative Commons licence.

This BBC News article leads with a reasonably interesting geographic fact: that Mount Hope, on the Antarctic Peninsula, has been remeasured at 3,239 metres, making it the tallest mountain in territory claimed by the United Kingdom. (Its location is also claimed by Argentina and Chile.) But it’s really about the British Antarctic Survey, who are using stereographic satellite data to create more accurate maps of Antarctica’s mountains for pilots operating on the continent. BAS press release. [Kenneth Field]

20 Years of Observing Our Living Planet


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:

Animations available for download hereGuardian coverage. [Benjamin Hennig]

Mapping Glacial Retreat

Elevation change of Mount Rainier glaciers, 1970-2016. David Shean/University of Washington.

Using elevation data from stereo satellite observations, David Shean is mapping the retreat of some 1,200 mountain glaciers in the continental United States. “Until recently, glaciers in the United States have been measured in two ways: placing stakes in the snow, as federal scientists have done each year since 1957 at South Cascade Glacier in Washington state; or tracking glacier area using photographs from airplanes and satellites.” Shean’s method, which measures each glacier twice a year and uses automated software to track changes, seems to cover a lot more territory. [GIS and Science]

A Look at GOES-16’s Imagery

This NOAA article looks at three kinds of imagery provided by the GOES-16 geostationary weather satellite: GeoColor, the Geostationary Lightning Mapper (!), and full disk infrared imagery from the Advanced Baseline Imager. GOES-16 launched last November and is currently in the checkout phase before it replaces GOES-13 at 75° west latitude.

Mapping Global Landslide Susceptibility

Image: Jesse Allen. Landslide susceptibility data: Thomas Stanley and Dalia Kirschbaum (NASA/GSFC). Topographic data: SRTM. (NASA Earth Observatory)

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]

Mapping Global Sea Surface Height

Credit: NASA/JPL Ocean Surface Topography Team.

Jason-3 is the latest earth observation satellite tasked with measuring global sea surface height; its data will be used in weather and climate research (e.g., El Niño, climate change). Launched on January 17, it’s now in its six-month checkout phase and has produced its first complete map, which corresponds well with the map produced by the still-operational Jason-2 satellite, so that’s a good sign. [via]

Mapping Nitrogen Dioxide Pollution

A decade’s worth of data from the Ozone Monitoring Instrument aboard the Aura satellite reveals the change in global nitrogen dioxide (NO2) pollution from 2005 to 2014: down significantly in some areas, due to stricter emissions controls, but up sharply in others. More at NASA Earth Observatory.

Lake Poopó Dries Up

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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 NewsThe Independent.

New Year’s Flooding in the Midwest

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These two Landsat images illustrate the extent of flooding along the Wabash and Illinois Rivers at the end of last year, as 6-10 inches of rain fell over the midwestern United States. The image from 8 December 2015, above left, shows normal water levels; the image from 1 January  2016, above right, shows the rivers in flood. Use the slider to compare the two views. Original image. [via]

Pacific Ocean Time Lapse

Clouds swirl across the Pacific Ocean in this time lapse. The data is from Himawari-8, a Japanese weather satellite in geostationary orbit over New Guinea. Every 10 minutes, it photographs the hemisphere below it. This animation is a loop of yesterday’s images. Strong winds head from East Asia, in the upper left, toward Alaska, hidden by clouds in the upper right. Australia is in the bottom center, with the edge of the Antarctic ice sheet below it and tropic storm Ula to its right. The reflection of the sun on smooth water, called sunglint, moves east to west across the Pacific just south of the Equator. At this time of year – the Southern Hemisphere’s summer – the North Pole is never sunlit, but the South Pole always is.

A post shared by Mapbox (@mapbox) on

From Mapbox’s Instagram account (via).

Mapping the Thaw

Scientists have been tracking seasonal freeze-thaw patterns for 30 years. This map, produced from data collected by NASA’s Soil Moisture Active Passive satellite, “shows the freeze-thaw status of areas north of 45 degrees latitude on March 5, 2015, as spring approached. Frozen land is blue; thawed land is pink. The measurement is possible because frozen water forms crystalline structures that can be detected by satellites.” NASA Earth Observatory.

Herbal Earth

Herbal Earth
Today NASA released a set of vegetation maps based on data from the Suomi NPP satellite. Flickr photoset, YouTube video. The maps depict a year’s worth of changes in vegetation. “High values of Normalized Difference Vegetation Index, or NDVI, represent dense green functioning vegetation and low NDVI values represent sparse green vegetation or vegetation under stress from limiting conditions, such as drought.” Image credit: NASA/NOAA.