For the 2017 solar eclipse, NASA published eclipse maps that took the irregular umbral shadow of the moon into account: the umbra is neither circular nor oval but irregular—more polygonal—thanks to the uneven topography and elevation of both the moon and the earth. Not accounting for that introduces errors into the map that could make the difference between observing a partial rather than a total eclipse. The process behind those more accurate eclipse maps, which involves computer processing of both lunar and terrestrial elevation models, has now been published in The Astrophysical Journal. [Bad Astronomy]
The animation shows sea surface height anomalies around the world: Red and orange indicate ocean heights that were higher than the global mean sea surface height, while blue represents heights lower than the mean. Sea level differences can highlight ocean currents, like the Gulf Stream coming off the U.S. East Coast or the Kuroshio current off the east coast of Japan. Sea surface height can also indicate regions of relatively warmer water—like the eastern part of the equatorial Pacific Ocean during an El Niño—because water expands as it warms.
Satellite observations have made it possible to evaluate the success of Ukraine’s wheat and barley harvest, even in active war zones or occupied territories. NASA Earth Observatory reports that the harvest was, in the end, larger than expected: “At the outset of Russia’s full-scale invasion in February, some analysts cautioned that 20 to 30 percent of Ukraine’s winter crops might not be harvested at the end of the summer. However, NASA Harvest’s analysis indicates that 94 percent of the winter crop was harvested, including 88 percent of winter crops in areas not controlled by Ukraine.”
A dust plume from the Sahara, driven by an atmospheric river, blew across western Europe this week, and friends from Spain to Germany experienced it. NASA Earth Observatory has satellite imagery of the plume, plus maps (above) showing “a model of the dust plumes blowing across North Africa and into Europe on March 14 and 15. The model was generated by the Goddard Earth Observing System Model, Version 5 (GEOS-5), a global atmospheric model that uses mathematical equations to represent physical processes. Measurements of physical properties like temperature, moisture, and wind speeds and directions are routinely folded into the model to keep the simulation as close to observed reality as possible.”
It turns out that the Geostationary Lightning Mapper (GLM) aboard the GOES-16 and GOES-17 earth observing satellites can do more than just detect lightning—it can also detect bolides, or very bright meteors, thanks to a new automatic detection algorithm. NASA Earth Observatory: “The map above shows the distribution of more than 3,000 bolides detected by the GLMs aboard GOES-16 and GOES-17 between July 2017 and January 2022. Blue points are bolides detected by GOES-16; pink points were detected by GOES-17. The lone pink point over the Atlantic Ocean was detected by GOES-17 during its commissioning phase before it was moved into its operational orbit over the West Coast.” (Bolides in the middle of the map are detected by both, and as you can see there’s a bit of parallax.)
Funded by NASA’s Carbon Monitoring System, scientists recently built a new series of maps detailing the geography of methane emissions from fossil fuel production. Using publicly available data reported in 2016, the research team plotted fuel exploitation emissions—or “fugitive emissions” as the UNFCCC calls them—that arise before the fuels are ever consumed. The maps delineate where these emissions occur based on the locations of coal mines, oil and gas wells, pipelines, refineries, and fuel storage and transportation infrastructure. The maps were recently published at NASA’s Goddard Earth Sciences Data and Information Services Center (GES DISC). (Note that 2016 was the most recent year with complete UN emissions data available at the time of this study.)
The first image from Landsat 9, taken on 31 October 2021, is of the Kimberly region of Western Australia. (NASA/USGS)
The latest of the Landsat satellites, Landsat 9, launched on September 27. Similar to Landsat 8 with slight equipment upgrades, it will replace Landsat 7 when it is fully operational next year. Right now it’s going through its 100-day check-out, after which NASA will hand it over to the USGS. As part of that check-out, its first images were recently released. [NASA Earth Observatory]
National Geographic looks at the rivalry between two early cartographers of Mars who based their maps on observations made during Mars’s “Great Opposition” in 1877: Nathaniel Green, whose Mars “was a delicately shaded world with landforms that gradually rose from vast plains and features that blended into one another” (pictured here) and Giovanni Schiaparelli, whose Mars had more detail—including those famous canals—but was less accurate.
A new study maps the possible locations of subsurface water-ice reservoirs, vital for any crewed missions. [Sky & Telescope]
NASA Earth Observatory: “The map above shows air temperatures across the United States on September 6, 2020, when much of the Southwest roasted in a dramatic heatwave. The map was derived from the Goddard Earth Observing System (GEOS) model and represents temperatures at 2 meters (about 6.5 feet) above the ground. The darkest red areas are where the model shows temperatures surpassing 113°F (45°C).” Heat waves in southern California have become “more frequent, intense, and longer-lasting,” the article goes on to say.
NASA Earth Observatory has had several stories on the western U.S. wildfires, gathered here. This story summarizes the situation; satellite images of the smoke generated by the fires can be seen here, here and here.
One-third of the United States is currently affected by at least moderate levels of drought, NASA Earth Observatory reports.
The map above shows conditions in the continental U.S. as of August 11, 2020, as reported by the U.S. Drought Monitor program, a partnership of the U.S. Department of Agriculture, the National Oceanic and Atmospheric Administration, and the University of Nebraska—Lincoln. The map depicts drought intensity in progressive shades of orange to red and is based on measurements of climate, soil, and water conditions from more than 350 federal, state, and local observers around the country. NASA provides experimental measurements and models to this drought monitoring effort.
According to the Drought Monitor, more than 93 percent of the land area in Utah, Colorado, Nevada, and New Mexico is in some level of drought; 69 percent of Utah is in severe drought, as is 61 percent of Colorado. More than three-fourths of Oregon, Arizona, and Wyoming are also in drought. The effects of “severe” drought include stunted and browning crops, limited pasture yields, dust storms, reduced well water levels, and an increase in the number and severity of wildfires. Most of those areas had no sign of drought in the mid-summer of 2019.
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.)
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.
This interferogram shows the ground displacement caused by last week’s earthquakes in southern California. Produced by NASA’s Jet Propulsion Laboratory, it’s based on synthetic aperture radar (SAR) images from JAXA’s ALOS-2 satellite taken both before (16 April 2018) and after (8 July 2019) the earthquakes. Each colour cycle represents 12 centimetres (4.8 inches) of ground displacement.
