Glowing bioluminescent plankton - Maldives

Glowing bioluminescent plankton in the tide line washes up onto a beach on Vaadhoo Island, Raa Atoll, Maldives, with stars above and a ship's lights on the horizon

Picture: Doug Perrine / Barcroft Media

ESA Envisat: Earth from Space: Historical view

West Africa’s coast along the Atlantic Ocean is pictured in this first image from Envisat’s MERIS instrument nearly a decade ago.

This week, Envisat celebrated ten years in orbit. The Medium Resolution Imaging Spectrometer (MERIS) on board the satellite was developed to measure sea colour in oceans and coastal areas, although it has been used for a variety of additional applications over the years.

Happy Birthday ESA's ENVISAT (Video)

Envisat carries ten sensors, collecting imagery and other data on Earth’s land, oceans, atmosphere, temperature and ice cover.

The first batch of data from the satellite in March 2002 was acquired via the Kiruna station in Sweden and processed at ESA’s ESRIN establishment in Italy and other centres throughout Europe.

In this first image from MERIS on 22 March 2002, a very dry desert directly borders the ocean teeming with life. To the south, a high concentration of phytoplankton was detected along the coasts of Senegal, the Gambia and Guinea-Bissau.

Small, single-celled phytoplankton play a key role in the marine food chain. They convert sunlight, carbon dioxide and nutrients into carbohydrates on which nearly all life in the ocean depends.

In most parts of Earth’s oceans, phytoplankton concentration is extremely low. However, in ‘upwelling areas’ like the one pictured here, the ocean becomes rich in minerals from the mixing of surface waters with deeper waters.

The most important fishing grounds can be found in these upwelling areas. Climate change has an effect on the intensity and geographical position of these areas, which, in turn, has important consequences for the fishing industries and those who depend on them.

Also evident in this image is the transition from the dry desert lands in the north through the savannah and to tropical vegetation in the south, which receives more rainfall. MERIS can monitor land use that leads to increased erosion and soil loss.

The Image of the Week is featured on ESA Web-TV, broadcast online every Friday at 10:00 CET.

The UFO In Baltic Sea

Envisat Medium Resolution Imaging Spectrometer (MERIS) satellite image acquired July 11, 2010 shows blue-green algae blooms in the Baltic Sea.

The term "Algae bloom" is used to describe the multiplying of phytoplankton, microscopic marine plants that drift on or near the surface of the sea. 

While individually microscopic, the chlorophyll that phytoplankton use for photosynthesis collectively tints the surrounding ocean waters, providing a means of detecting these tiny organisms from space with dedicated 'ocean colour' sensors.

Germany, Sweden, Estonia, Latvia, Lithuania, Russia and Poland are pictured bordering the sea.

(Photo: REUTERS/European Space Agency/)

 
In 2011, an extraordinary circular object was seen on the surface of the Baltic Sea by a group of stranded ship hunters. This year, they claimed again that they have witnessed another strange object with a disc-like shape around 200 meters away- from the area where they first saw the same kind of thing.

The leader of the team, Peter Lindberg, joked that the first thing they have discovered 300 feet below the sea surface might be a UFO, or an unidentified flying object, when interviewed by CNN.

The first bizarre object that was discovered June last year has a diameter of 195 feet. Believers thought of it as a stranded UFO, which had smashed into the sea leaving behind a trail of damage about 900 feet. The story regarding this so-called UFO was exposed at News.com.au.

CNN news revealed how the group found out about the objects.

The hunters were using an imaging technique that tracks down and magnetize a sonar "towfish." The towfish actually appears sideways underwater. They placed the device at the back of the boat, where it suitably produces a sound that echoes to map underwater.

The Baltic Sea is like a breeding ground where you can typically discover retrieved objects. Ardreas Olsson, a sonar expert, said they have identified 20,000 salvaged objects mostly stranded ships in the Baltic Sea. Olsson thinks that there could be over 100,000 things to discover underwater. He's excited to encounter more discoveries.

UFO believers are for sure more than excited to hear updates about the new found object.

ESA ENVISAT: A southern summer bloom

In this ESA Envisat image, a phytoplankton bloom swirls a figure-of-8 in the South Atlantic Ocean about 600 km east of the Falkland Islands.

During this period in the southern hemisphere, the ocean becomes rich in minerals from the mixing of surface waters with deeper waters.

Phytoplankton depend on these minerals, making blooms like this common in the spring and summer.

These microscopic organisms are the base of the marine food chain, and play a huge role in the removal of carbon dioxide from the atmosphere and the production of oxygen in the oceans.

By helping to regulate the carbon cycle, phytoplankton are important to the global climate system.

Different types and quantities of phytoplankton exhibit different colours, such as the blues and greens in this image.

Earth-observing satellites like Envisat can monitor these algal blooms. Once a bloom begins, an ocean colour sensor can make an initial identification of its chlorophyll pigment, and therefore its species and toxicity.

Since the phytoplankton are sensitive to environmental changes, it is important to monitor and model them for climate change calculations and to identify potentially harmful blooms.

Envisat’s MERIS instrument acquired this image on 2 December 2011 at a resolution of 300 m.

Missing link found in the biology of cloud formation

Scientists have known for two decades that sulphur compounds that are produced by bacterioplankton as they consume decaying algae in the ocean cycle through two paths.

In one, a sulphur compound dimethylsulphide, or DMS, goes into the atmosphere, where it leads to water droplet formation - the basis of clouds that cool the Earth. In the other, a sulphur compound goes into the ocean's food web, where it is eaten and returned to seawater.

What they haven't known is how sulphur is routed one way or the other or why.

They also have wondered what if - in a time of growing concern about global warming - it was possible to divert the sulphur compound that goes into the oceans into the atmosphere, helping to mitigate global warming?

A study by researchers at the University of Georgia just published in Nature brings the possibility of using the sulphur cycle to mitigate global warming closer with the identification of the steps in the biochemical pathway that controls how bacteria release the sulphur compound methanethiol, or MeSH, into the microbial food web in the oceans and the genes responsible for that process.

"With our increased understanding of the sulphur cycle in the ocean," said study co-author William (Barny) Whitman, "we are now better able to evaluate the impacts of climate change on the process and the potential for its manipulation, which has been proposed as a way to mitigate global warming.

"It's wonderful to have this much understanding of a major biogeochemical process," noted Whitman, distinguished research professor and head of the department of microbiology in the Franklin College of Arts and Sciences.

In addition to elucidating the steps in the pathway and identifying the responsible genes, the team of UGA microbiologists, marine scientists and chemists discovered that the pathway is found widely, not only among bacterioplankton in the ocean but also in non-marine environments.

"The big mystery about bacteria is what they are doing in nature," Whitman said. "The organisms metabolise compounds for their own needs. We need to understand what they are getting out of it to understand what it means for the ocean, and now it will be possible to look at the environmental importance of this process and how it's regulated." That will help to answer the "why" of the two sulphur fates.

Co-authors of the Nature paper were UGA graduate students Chris Reisch and Vanessa Varaljay, department of microbiology; graduate student Melissa Stoudemayer and Jon Amster, professor and head, department of chemistry; and distinguished research professor Mary Ann Moran, department of marine sciences-all in the Franklin College of Arts and Sciences.

The collaborators in this study built on a line of research begun at UGA over a decade ago. Moran's early research showed that an abundant group of bacteria known as marine roseobacters play a role in moving dimethylsulphonioproprionate (DMSP), the chemical made by marine algae and released into the water upon their death, into the atmosphere as the compound dimethylsulphide (DMS).

Missing link found in the biology of cloud formation over the oceans

NASA MODIS: Bloom around the Chatham Islands, New Zealand

The waters around New Zealand’s Chatham Islands teems with life.

The highly productive waters support massive phytoplankton blooms that sustain valuable stocks of fish.

This image, taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite on December 5, 2010, shows the large annual spring-time bloom.

The bloom is an array of colors from deep green to electric blue, and is probably made up of many different types of marine life, primarily phytoplankton.

The phytoplankton, plant-like organisms, contribute to making the ocean in this region a carbon sink, a place where the ocean takes in more carbon dioxide than it releases into the atmosphere.

The ocean is productive in this region because the topography of the ocean floor brings two currents together around the Chatham Islands. The islands sit on the Chatham Rise, an underwater plateau that stretches from New Zealand’s South Island east to just beyond the Chatham Islands.

The water north and south of the plateau is very deep. Cold, nutrient-rich, but iron-poor water from the Antarctic flows south of the Chatham Rise. To the north is mostly warm, nutrient-poor, but iron-rich water from the subtropics.

The two pools of water come together in a current that rides over the plateau, mixing cold water with warm.

The mixed water in the current provides both the nutrients and iron fertilizers needed to support large blooms around the Chatham Islands. The current, and therefore, the bloom, is strongest in the spring and the fall.

NASA MODIS Image: Plankton Bloom off Namibia

A plankton bloom is pictured off the coast of The Republic of Namibia.

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite captured this natural-colour image of ocean waters glowing a bright peacock green off the northern Namibian coast.

Picture: NASA / BARCROFT

NASA Image: Phytoplankton

In the style of Van Gogh’s painting “Starry Night,” massive congregations of greenish phytoplankton swirl in the dark water around Gotland, a Swedish island in the Baltic Sea.

Phytoplankton are microscopic marine plants that form the first link in nearly all ocean food chains. Population explosions, or blooms, of phytoplankton, like the one shown here, occur when deep currents bring nutrients up to sunlit surface waters, fueling the growth and reproduction of these tiny plants.

More out of this world pics from Flickr

ESA Observing the Earth from Space: Plankton Bloom arrives in Scandinavia

ESA - Observing the Earth - Earth from Space: Plankton arrives in Scandinavia

Envisat captures a crescent-shaped string of plankton in the North Sea weaving through the Scandinavian region.

Norway (left) and Sweden (right), part of the Scandinavian Peninsula, are visible at the top, and Denmark is at bottom right.

The emerald green lake seen in Sweden is Vänern, the country’s largest.

The green water around Denmark is due to sediments being transported in the water. Also visible (image centre) is Norway’s second largest fjord, Hardangerfjord. Envisat's MERIS acquired this image on 3 May 2010 at a resolution of 300 m.

Credits: ESA