We don't need a scientist to tell us that city streets catch and hold heat. Anyone who's walked barefoot from a parking lot to a beach can tell you that. What scientists can help us understand, particularly scientists who work with spaceborne, remotely sensed data, is just how big a difference there is between cities and the countryside. That gap is sometimes referred to as the urban heat island effect. At the height of summer, heat disparities can have a large impact on at risk human populations. On this episode of Eyes on Earth, we hear from a remote sensing scientist and a sustainability coordinator for the city of Los Angeles who teamed up to study the impact of cool pavement coating as an urban heat mitigation strategy.

Spaceborne sensors orbit hundreds of miles over our heads. Even the most advanced among them struggle to capture high-resolution imagery of individual human beings. Mosquitos, of course, are far smaller than we are. Clearly, sensors on a satellite or space station can’t see them. Even so, these sensors can gather a host of information that helps to understand the movements and behaviors of these pesky little disease vectors, which are responsible for at least a million deaths a year. Mosquitos are more active under certain environmental conditions, for example, and those conditions can be tracked at wide scales from above. Changes to the land’s surface can also make it easier for mosquitos to proliferate. On this episode of Eyes on Earth, we learn how a sensor onboard the International Space Station was used to calculate West Nile virus risk in California’s San Joaquin River Valley.

Clouds of dust kicked up in places like the Sahara can travel thousands of miles across the planet. We can see those clouds in satellite imagery, but we don’t typically know much about the composition of that dust. That’s a huge blind spot, because those unknown characteristics—such as the particles’ lightness or darkness—have an impact on what they do. The warming and cooling of the atmosphere, snow melt, ocean or rain forest fertilization, and even cloud formation can all be affected by dust cloud composition. Mapping those dust sources is the focus of the Earth Surface Mineral Dust Source Investigation, or EMIT, which will be supported by NASA’s Land Processes Distributed Active Archive Center (LP DAAC), which is located at the USGS EROS Center. On this episode of Eyes on Earth, we hear about the importance of the mission from three members of the EMIT Science Team.

When the first Landsat satellite launched 50 years ago, it was the only game in town in terms of civilian land remote sensing. In the years that followed, a host of satellites have launched to serve similar purposes. But that data doesn't always play well together. Subtle differences between the measurements taken by satellites make it difficult to do apples-to-apples comparisons of land change. On this episode of Eyes on Earth, we hear from the USGS partners working with partners in Australia to launch a satellite cross calibration mission that will offer a common reference post and serve as a sort of “translation tool” to help remote sensing scientists to use datasets together to study changes to the Earth’s surface.

Some plants are simply better at making use of their water supply than others. More efficient plants can capture more carbon with less water, which has implications for carbon sequestration and ultimately for climate change modeling. In other words, the more we understand about water use efficiency, the more reliable our climate change models can be. And the only way to measure efficiency at the global scale is from space. On this episode of Eyes on Earth, we hear from a scientist who studied global water use using a sensor called ECOSTRESS, whose data are housed at the USGS EROS Center, in NASA’s Land Processes Distributed Active Archive Center (LP DAAC).

The boreal forest, or taiga, stretches across nearly 5.7 million square miles in the northern latitudes. That’s nearly a quarter of all forested lands in the world. This sprawling biome also happens to be one of the most rapidly shifting in the face of climate change. Many studies have suggested that the taiga tree line is moving northward as temperatures warm worldwide, edging itself into the colder tundra. On this episode of Eyes On Earth, we hear from Professor Logan Berner, part of team at Northern Arizona University’s Global Earth Observation and Dynamics of Ecosystems (GEODE) Lab that used USGS Landsat satellite data to track and quantify the northward shift of the boreal tree line.

In this episode of Eyes on Earth, we zero in on the use of USGS Land Change Monitoring, Assessment, and Projection (LCMAP) products to examine the effects of drought on California’s Blue Oaks. LCMAP datasets are built from Landsat data and reveal the land cover and change of every pixel in the conterminous United States, dating back to 1985. In this case, LCMAP helped identify areas of declines and losses of the Blue Oak trees that are native to California and found in the foothills surrounding the central valley and along the coast.

Summary: The Earth observation data archived here have plenty of value to the study of aquatic ecosystems. Landsat satellites can capture harmful algal blooms, for example. Spaceborne sensors can also record land surface temperatures, and that includes water surfaces. On this episode of Eyes on Earth, we hear about how a sensor called ECOSTRESS can be used to measure water temperatures at different times of day, and how those measurements could be useful in the monitoring and management of the endangered Delta smelt. ECOSTRESS data are available through the NASA Land Processes Distributed Active Archive Center (LP DAAC), located in the USGS EROS Center.

Land change is a constant. Even land areas that see little major change can see disruptions from storms, heat waves, wildfires, or invasive species. But major changes aren't uncommon, either. Each year in the U.S., farm fields become tracts of suburban homes, wetlands become more permanent bodies of water, and shrublands burn to be replaced with grasslands. A team of researchers with the USGS Land Change Monitoring, Assessment, and Projection initiative (LCMAP) recently released a study documenting land cover class change from 1985-2016. On this episode of Eyes on Earth, we talk to the study’s lead author about what they learned about land change, and about how land change ties in to policy, economic trends, weather patterns and more.

The sturdy root systems of mangrove forests act as buffer zones along the coastlines of some of the planet’s most vulnerable communities, protecting lives, ecosystems and property from the rigors of hurricanes and tsunamis. The dual stressors of climate change and man-made changes to the environment such as offshore aquaculture have damaged these critical buffer zones in recent years. Remote sensing scientists are using satellite data to understand the impact those changes will have on the communities they protect as temperatures continue to warm worldwide and extreme weather events become more frequent. On this episode of Eyes on Earth, we talk to one of those scientists, Dr. Lola Fatoyinbo.