NASA Sets the PACE for Advanced Studies of Earth's Ocean and Atmosphere
PACE's advanced technologies will provide unprecedented insight into Earth's ocean and atmosphere, which impact our everyday lives by regulating climate and making our planet habitable. Our oceans teem with life, supporting many of Earth's economies. New discoveries in Earth's living ocean will be revealed with PACE's global observations, such as the diversity of organismsfueling marine food webs and how ecosystems respond to environmental change. PACE will observe our atmosphere to study clouds along with the tiny airborne particles known as aerosols. Looking at the ocean, clouds, and aerosols together will improve our knowledge of the roles each plays in our changing planet.
PACE's data will reveal interactions between the ocean and atmosphere, including how they exchange carbon dioxide and how atmospheric aerosols might fuel phytoplankton growth in the surface ocean. Novel uses of PACE data – from identifying the extent and duration of harmful algal blooms to improving our understanding of air quality – will result in direct economic and societal benefits. By extending and expanding NASA's long record of satellite observations of our living planet, we will take Earth's pulse in new ways for decades to come.
Our ocean is teeming with life and many of its most vital species are invisible to us.
Like on land, the ocean has deserts, forests, meadows, and jungles that provide homes for grazers, predators, scavengers and plants. This diversity of ecosystems is determined by microscopic oceanic vegetation – phytoplankton. These tiny plant-like organisms come in many different shapes, sizes, and colors. Phytoplankton diversity determines their role in oceanic ecosystems and their success in capturing energy from the sun and carbon from the atmosphere.
Phytoplankton provide food for small zooplankton. Like humans, these grazers actively select their food. Similarly, larger zooplankton hunt for and feed upon nutritious smaller zooplankton. Step by step, energy captured from phytoplankton climbs higher into the food web as it transfers to bigger creatures, and ultimately to humans.
Although the ocean is a three-dimensional fluid that is constantly in motion, it supports distinct habitats. The North Atlantic is home to highly productive "forests" each spring, for example, as blooms of carbon-rich phytoplankton fuel the fisheries of New England. The crystalline waters around Florida host productive coral reefs and fisheries, but also occasionally toxic phytoplankton.
Current ocean-viewing satellites reveal the quantity - but, not the diversity - of phytoplankton. For the first time, PACE's unprecedented imaging technology will:
Reveal the diversity of phytoplankton found in our ocean on global scales;
Allow us understand the role that phytoplankton diversity has on life in the ocean; and
Help us predict the “boom or bust” of fisheries, appearance of harmful algal blooms, and other marine hazards that affect local and global economies.
Why do we need PACE? To understand how phytoplankton diversity impacts human life.
Small particles suspended in the atmosphere (aerosols) and clouds are the largest sources of uncertainty in our understanding of how much sunlight is being reflected and absorbed by the Earth and its atmosphere.
Complex interactions between clouds and aerosols in which cloud drops form on aerosols and aerosols are themselves washed out of the air by rain are not well understood. Adding complication, many different types of aerosols — for example, smoke, dust, salt and sulfate — absorb and reflect different fractions of sunlight.
Clouds, aerosol types and their interactions vary substantially both geographically and with time. Thus, only global Earth-observing satellite measurements can capture a complete and accurate picture of how much energy from the sun our home planet is absorbing. PACE will continue and expand NASA's global cloud and aerosol observations in order to better understand their role in controlling our climate.
Aerosol data will not only benefit atmospheric science but ocean science, as well. Retrieving ocean color information is challenging because 90% or more of the signal observed by PACE will be contributed by the atmosphere, including aerosols, situated between the ocean and satellite. We must therefore have strong knowledge of the atmosphere, and understand the aerosols present in a scene, for PACE to accurately "see" the ocean.
Aerosols and clouds control the amount of energy from the sun that is absorbed by the earth. PACE will:
Globally determine aerosol quantity, and provide new insight into aerosol properties;
Monitor cloud properties, and the interaction between aerosols and clouds; and therefore
Observe fundamental components of our global climate.
Carbon exists in forms that range from invisible gases to diamonds to the organic matter that forms all living organisms. In the ocean, a system of physical and biological processes drives transitions between forms of carbon, which ultimately supports life on this planet and regulates our livable environment. Through photosynthesis, marine phytoplankton convert carbon dioxide gas into organic cellular material that supplies food and energy to all life forms within the food web. Through other mechanisms within this web, carbon can also adopt other forms; for example, it can be returned to the atmosphere as carbon dioxide through respiration or sink deep into the ocean as non-living particles.
In many ways, phytoplankton diversity dictates carbon pathways on Earth. Like falling leaves in autumn, larger phytoplankton species can sink from the ocean surface to the sea floor, effectively removing carbon from contact with the atmosphere. Many species of phytoplankton provide nutritious food sources for larger zooplankton. The carbon captured by zooplankton is partially returned to the atmosphere through respiration and partially exported to the deep ocean during nighttime migration and excretion. In addition, many zooplankton release partially ingested carbon in the form of dissolved material. Marine bacteria, another type of plankton, use this dissolved carbon as an energy source, ultimately transitioning it back into its gaseous form.
As illustrated above, carbon pathways are many and diverse – even small disturbances in an oceanic ecosystem can push carbon towards an alternate route. Seeing the diversity of planktonic life is critical to understanding how carbon moves to and from the ocean and atmosphere.
Current ocean-viewing satellites reveal the quantity - but not the diversity - of phytoplankton. For the first time, PACE's unprecedented imaging technology will:
Reveal the diversity of phytoplankton found in our ocean on global scales;
Allow us to understand the role that phytoplankton diversity has on cycling of carbon in the ocean; and
Help us predict the routes that carbon will take in today's ocean and tomorrow's.
The PACE mission will provide a combination of global atmospheric and oceanic observations to benefit society in the areas of water resources, impact of disasters, ecological forecasting, human health, and air quality.
PACE Applications will partner with public and private organizations on ways to apply data from PACE and its scientific findings in their decision-making activities and services, helping to improve the quality of life and strengthen the economy.
Webmaster: Lisa Taylor
Fri Apr 21 16:53:49 2017