Image from TERRA
Fri, 17 Aug 2018 13:56 EDT

NASA's Terra satellite looked at water vapor and cloud top temperatures when it passed over the recently strengthened Typhoon Soulik in the Northwestern Pacific Ocean.

Image from TERRA
Mon, 13 Aug 2018 14:29 EDT

The largest fire in California's history, the Mendocino Complex, is still spewing clouds of smoke across the state.

Image from TERRA
Mon, 13 Aug 2018 12:38 EDT

After Tropical Storm Yagi made landfall in China, NASA's Aqua satellite saw the storm was moving inland and dropping heavy rainfall.

Month: September 2015

Satellite Data Helps Migrating Birds Survive

Shorebird populations are struggling to find wetlands on their epic migrations down the Pacific Flyway, stemming from Alaska and Canada down to South America. As water resources have decreased in the Central Valley of California due to development, agriculture and other land use changes, resting and feeding grounds for migratory birds has decreased.

A team from Cornell Lab of Ornithology’s was able to use data from the Moderate Imaging Spectroradiometer (MODIS) on-board NASA’s Terra and Aqua satellites, along with data from Landsat to identify areas that could be turned into “pop-up habitats,” where rice fields could be flooded to provide temporary habitats for migrating birds for a couple weeks per year.

To identify areas that would be beneficial “pop-up habitats,” satellite data on the location and timing of surface water was matched with migration patterns of shorebirds collected from the eBird program, a citizen science bird watching program that collects data on bird sightings. The result is the BirdReturns program, a partnership between the Nature Conservancy and the California Rice Commission that compensates rice farmers to flood their rice fields at particular times to provide migratory habitat for shorebirds.

Efforts like this can help land managers better allocate valuable resources, such as water in California, where they are needed when competition for these resources are high.

Read more on NASA.gov

Terra Helps See Earth’s 3 Trillion Trees

global.fallA recent study published in Nature now estimates that there are 3.04 trillion trees on Earth, a number that is almost 8 times higher than previous estimates

Scientists rely primarily on remotely-sensed to obtain estimates of global tree populations. Satellites provide the best opportunity to achieve a global perspective, but their view of tree forest canopies from above tends to obscure individual trees and shorter trees, making it difficult to make accurate estimates. In addition, satellites are limited by their spatial resolution, not every tree is as obvious as a Redwood alone in a field. The Redwood example also points to another complication, the definition of a tree, which for most studies, including the one in Nature, is vegetation with woody stems 10 cm in diameter or larger at chest height. Thus, counting trees is a difficult process because they can vary in size and can hide beneath the canopy of larger trees, as well as be too small to be seen in satellite images.

To get a better estimate of the actual number of trees on Earth, researchers combined data from multiple vegetation indexes, including the Enhanced Vegetation Index (EVI) from the Moderate Imaging Spectroradiometer (MODIS) onboard Terra, with actual tree counts for over 430,000 hectares from 14 different biomes on Earth (there is an estimated 4 million hectares of forested land on Earth). Merging the ground measurements and applying them to the different areas of land cover visible through satellite images resulted in the more accurate estimate of tree population possible with surprisingly large results.

Read more on nature.com

Santa Ana Vs. Summer Fires: MODIS Helps Determine Most Destructive

cedarfire_tmo_2003299Wildfires perpetuated by the Santa Ana winds can sweep through southern California in the fall and winter; where as, summer wildfires occur much earlier in the year. Both seasons are marked by approximately the same number of acres burned, but researchers recently quanitified which was more destructive.

To quantify each season’s destructiveness, data from the Moderate Imaging Spectroradiometer (MODIS) on-board Terra and Aqua on burn areas in southern California was combined with fire records and economic data to determine how destructive Santa Ana fires are compared to summer wildfires.

From their research they determined that Santa Ana fires caused about 80 percent more economic losses than the summer fires. MODIS data shows that Santa Ana fires may cover approximately the same area as summer fires, but spread more quickly and in the direction of more populated areas with higher property values than summer inland fires, explaining why the Santa Ana- fueled fires are more destructive.

Read more on NASA’s Earth Observatory

Read the entire paper from Environmental Research Letters

In Africa, More Smoke Leads to Less Rain

earth20150806b-16

The Moderate Resolution Imaging Spectrometer (MODIS) instrument on NASA’s Aqua satellite captured this image of numerous fires burning in the transition zone between the Sahara Desert to the north and the greener savannas to the south. The image, dating from November 2004, includes parts of Sudan, Chad and other nations to the south and west. Image credit: NASA

A new study is the first to use satellite observations to look at how smoke affects rainfall. Specifically focusing on agricultural fires in North Africa that reduce the amount of rainfall during the dry season.

African agricultural fires, a major source of fires globally, are used to increase agricultural productivity and clear land for farming.  Large plumes are formed by these fires, impacting weather and precipitation patterns, while carrying nutrients to land and ocean regions downwind.

Using satellite data from three NASA satellites from varying passover times along with weather records, Michael Tosca and his colleagues from NASA’s Jet Propulsion Laboratory in Pasadena, California, assessed how microscopic smoke particles affect the formation of clouds and rainfall in Africa, north of the equator and south of the Saharan Desert.

Using images of smokey areas taken by  the Multi-angle Imaging Spectroradiometer instrument (MISR) on-board Terra from 2006 to 2010, Tosca and his colleagues were able to match “each smoky image with a smoke-free scene in statistically identical weather conditions.” From this information they compared the changing cloud cover throughout the day, using data from Tropical Rainfall Measuring Mission (TRMM) and Aqua, which pass over the same region at later times in the day.

Clouds need small airborne particles, aerosols, to act as a nucleus on which water vapor can condense and form clouds. Black carbon, a common aerosols in African fires, absorbs radiation from the sun and heats up the surrounding air.  When a layer of this soot-filled warm air forms, rising air from Earth’s surface is blocked by the warm layer, causing air from Earth’s surface to spread out horizontally. Rain clouds are produced from air moving up in updrafts and then condensing and falling, a process called convection.  When the air cannot penetrate the soot-filled layer, rain cloud formation is suppressed. “The researchers found that less cloud cover built up throughout the day in smoky scenes than in scenes without smoke.”

The NASA press release is available online at: http://www.jpl.nasa.gov/news/news.php?feature=4681

The study is available online at: http://onlinelibrary.wiley.com/doi/10.1002/2015GL065063/full

Read More on NASA’s Earth Observatory

MODIS Captures Image of Swirling Dust Storm

iraq_tmo_2015244On September 1st, 2015 Terra’s Moderate Imaging Spectroradiometer (MODIS) captured this image of swirling skies filled with dust over the Middle East. Unlike Haboobs, which are short-lived, these dust storms can last for days and are typically associated with northwesterly wind patterns, known as the shamal. The cyclonic swirl associated with low pressure systems is clearly visible in the dust.

Read more on NASA’s Earth Observatory