NASA LandSat-8: Phytoplankton green blue algae bloom near the Pribilof Islands

Phytoplankton bloom (green and blue swirls) near the Pribilof Islands off the coast of Alaska, in the Bering Sea. 

The turquoise waters are likely coloured by a type of phytoplankton called coccolithophores. 

This Sept. 22, 2014, image was created with Landsat 8 data.

Image Credit: NASA's Goddard Space Flight Center, Norman Kuring; USGS

The greens and blues of the ocean colour from NASA satellite data have provided new insights into how climate and ecosystem processes affect the growth cycles of phytoplankton (coccolithophores), microscopic aquatic plants important for fish populations and Earth’s carbon cycle.

At the bottom of the ocean’s food chain, phytoplankton account for roughly half of the net photosynthesis on Earth.

Their photosynthesis consumes carbon dioxide and plays a key role in transferring carbon from the atmosphere to the ocean.

Unlike the plant ecosystems on land, the amount of phytoplankton in the ocean is always followed closely by the abundance of organisms that eat phytoplankton, creating a perpetual dance between predators and prey.

This new analysis shows how tiny imbalances in this predator-prey relationship, caused by environmental variability, give rise to massive phytoplankton blooms, having huge impacts on ocean productivity, fisheries and carbon cycling.

The study was released Thursday, Sept. 25, in the journal Nature Climate Change.

“The continuous year-in and year-out measurements provided by NASA’s ocean color satellites have dramatically changed our understanding of phytoplankton dynamics on the Earth,” said Mike Behrenfeld, author of the study and phytoplankton ecologist at Oregon State University, Corvallis, Oregon.

“What we now see is a closely linked system of phytoplankton cell division and consumption lying at the heart of the plant’s annual cycle.”

Behrenfeld calls this close predator-prey relationship the “Dance of the Plankton.”

This view is different from previous perspectives that have simply focused on environmental resources used by phytoplankton to grow, such as nutrients and light.

The new view is important because it reveals that tiny imbalances can greatly impact Earth’s ecology.

More Information:
"Climate-mediated dance of the plankton" Author: Michael J. Behrenfeld - Nature Climate Change 4, 880–887 (2014) doi:10.1038/nclimate2349

NASA Landsat-8: Tracking urban change and flood risk

This is an artist's rendition of the Landsat 8 satellite. 

Credit: NASA /USGS

When it comes to helping communities across the United States stay up-to-date on their flood risk, the Landsat satellite can take a bow.

Landsat 8 satellite images help track urban change, a factor that can impact a community's flood risk.

The Federal Emergency Management Agency (FEMA), uses these images to help identify where they should launch a new flood study.

Flood studies determine how prone different neighborhoods are to floods of a certain intensity or likelihood.

Successful flood studies require an arsenal of tools, however, including data on river flows and storm tides, hydrological and hydraulic analysis of landscape and river systems, and historic rain data, to name a few.

These studies have adding satellite data from Landsat 8 satellite to the toolkit. With its archive of images capturing sprawling cities and new developments, Landsat helps FEMA track how building and construction is impacting an area's landscape.

Earth-observing Landsat 8 satellites have been capturing images of the planet's surface since 1972.

Landsat 8, the newest satellite in the joint NASA and U.S. Geological Survey (USGS) program, was launched Feb. 11, 2013, and now collects more than 400 images per day.

New and archived Landsat data are available free to the public from USGS. Researchers put the free data to a multitude of uses.

"If you identify areas where urban change is accelerating, there are consequences," said Zack Roehr, a senior spatial analyst with Dewberry, Fairfax, Va., a FEMA subcontractor.

Urbanization can spell trouble for flood risk. Soil typically acts like a sponge, absorbing water from rainfall.

When soil is covered with concrete or other impermeable material, water has nowhere to flow except towards storms and rivers, thereby increasing flood risk.

"The ground is no longer able to hold water, which means local flooding sources are going to receive more of that water," Roehr said. "The flooding characteristics are going to change."

NASA Landsat-8: Sakura-jima volcano

Sakura-jima volcano emits a dense plume of ash over the Japanese island of Kyushu. 

Currently Japan's most active volcano, Sakura-jima explodes several hundred times each year. 

These eruptions are usually small, but the larger eruptions can generate ash plumes that rise 3,800 meters (12,000 feet) or more above the 1,040-meter (3,410-foot) summit. 

This true-colour image was collected by the Operational Land Imager on Landsat 8.

USGS LandSat-8: LDCM Earth Observation satellite appears to be working flawlessly

A new satellite hovering nearly 450 miles (725 kilometers) above the Earth appears to working flawlessly as it embarks on a 10-year mission to document the planet's surface, scientists and engineers at the U.S. Geological Survey's Earth Resources Observation and Science Center said Monday.

LDCM Landsat 8 is sending more than 400 data-filled images per day back to the EROS center north of Sioux Falls, where they will be archived and made available for free download by scientists or anyone else who's interested.

Tom Loveland

The center's mission requires images to be publicly available within 48 hours of their capture, though most will be ready within 24 hours, said project scientist Tom Loveland.

The new orbiter has several advantages over its still-functioning predecessor Landsat 7, which captures just 250 images a day.

Landsat 8 also boasts two new spectral bands, one to see deeper into oceans, lakes and rivers and another to detect cirrus clouds and correct for atmospheric effects, Loveland said.

The new satellite's infrared band is split into two, allowing for more accurate surface temperature readings, he added.

"It should really make a difference in our ability to map and characterize changes going on in the surface of the Earth," Loveland said.

NASA launched Landsat 8 into space in February. Since then, teams have been running it through a barrage of tests before placing the satellite into orbit 438 miles (705 kilometers) above the planet's surface.

Jim Nelson

"The spacecraft has been extremely healthy," said Jim Nelson, ground systems manager. "The instruments have performed really well."

The EROS Center, the main federal repository for satellite images, will officially take over the mission May 30 from NASA.

Since 1972, Landsat satellites have been continuously snapping pictures across the globe as part of a 40-year mission to document the planet.

Landsat 8, which is about the size of parcel delivery truck with a 30-foot (9-meter)-long deployed sheet of solar panels, is stocked with a 10-year supply of fuel. It travels at a speed of 17,000 miles (27,360 kilometers) per hour.

Landsat 8 will work in tandem with Landsat 7, launched in 1999, to take pictures of each inch of the planet's surface every eight days. Landsat 7 continues to operate despite a faulty scan line corrector that leaves zigzag gaps in some images.

Landsat 5, which dates back to 1984, worked decades past its expected mission end but began failing in November. Landsat 6 never reached orbit after its 1993 launch because of a ruptured manifold.

Nelson said the EROS Center has been preparing for the wave of new data, upgrading its ground station near Sioux Falls as well as partner facilities in Alaska and Norway.

It also overhauled its data processing and storage systems, "so we can get as much data as possible online for the users to get direct access to," Nelson said.

Loveland said there's a huge demand for the images in the scientific community, giving an example of a recent Brazilian Remote Sensing Symposium that drew more than 800 people looking to tap into the data.

The center used to charge for the images, but for years now, they've been free.

"When you put all this free stuff in universities, innovation happens," Loveland said."