NASA Sets the PACE for Advanced Studies of Earth's Ocean and Atmosphere
The Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission will deliver the most
comprehensive look at global ocean color measurements in NASA's history. Not only will PACE monitor the health of our ocean, its
science data will expand atmospheric studies by sensing our skies over an exceptionally broad spectrum
Being built and tested at the Goddard Space Flight Center, PACE will expand our knowledge of key climate variables such as aerosol particles and clouds. It will extend NASA's long-term record of the phytoplankton pigment, chlorophyll, while providing new insights on ocean biodiversity.
Movement in the ocean is a complex interplay of currents and eddies. And high above earth's surface, satellite sensors specifically tuned to see colors of the ocean provide valuable information about ocean ecology and the cycling of carbon in our ocean.
Carbon exists in many forms: from invisible gases to living things. For centuries, burning of fossil fuels has moved hydrocarbons from deep underground to Earth’s atmosphere. The ocean absorbs this carbon dioxide gas, which is converted to living matter and oxygen by single-celled algae called phytoplankton. Phytoplankton contain a pigment, chlorophyll, that absorbs red and blue wavelengths of sunlight and reflects the green, giving the ocean a blue-green color.
Phytoplankton swim weakly or not all. Despite their tiny size and being at mercy of the ocean's motion, these organisms are key to the health of our planet. This is because phytoplankton – and the animals that eat them – can move carbon deep into the ocean when they die. The more human-derived carbon dioxide stored in the deep ocean, the less will be stored in the atmosphere to trap heat at Earth’s surface.
Even though the ocean's role as a vast natural carbon reservoir sounds like a good thing, scientists are concerned about the biological impacts of increased marine carbon dioxide levels. For instance, a series of chemical reactions are making seawater more acidic, threatening marine biodiversity.
PACE's ocean color data will help researchers estimate the rates at which phytoplankton are absorbing carbon dioxide, producing oxygen, and changing seawater chemistry. When they observe variations in phytoplankton populations, they can investigate how those changes connect to other parts of the ocean and climate systems.
The atmosphere and ocean are inextricably linked. Earth relies on atmospheric circulation and ocean currents to regulate the distribution of heat. Thus deciphering the ocean-atmosphere conversation is key to predicting the future of our climate.
The amount of sun's heat reaching the ocean surface is tied to clouds and aerosols, tiny airborne particles and liquids suspended in our atmosphere. On the other hand, the ocean itself can be a strong source of atmospheric aerosols, influencing climate though direct obstruction of sunlight as well as changes to clouds' reflective properties.
There are significant gaps in scientific understanding on how clouds are formed and behave in remote marine environments. This information is crucial because Earth's heat balance is dominated by clouds over the ocean.
Ocean ecosystems also depend on fluxes between the atmosphere and ocean. Phytoplankton growth at the ocean's surface relies on the availability of sunlight and nutrients. In the open ocean, airborne dust can deliver nutrients that trigger phytoplankton blooms.
As our climate warms, changes in patterns of atmospheric input of dust will affect phytoplankton populations far from land. Moreover, continued use of fertilizers will deliver more nitrogen to marine ecosystems, particularly near coasts, with potential impacts on phytoplankton growth.
PACE's broad spectral coverage will also provide extended data records on clouds and aerosols which, according to the Intergovernmental Panel on Climate Change (2007), are the largest uncertainty in our understanding of physical climate.
The 2007 Report, Earth Science and Application from Space: National Imperatives for the Next Decade, called for "societal needs to guide scientific priorities more effectively."
In response, 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.
PACE observations will benefit a broad spectrum of people, including:
Operational users in various tribal, local, state, federal, and international agencies
The combination of high-quality, global atmospheric and oceanic observations provided by the PACE mission will provide direct benefits to society in the major NASA application areas of Oceans, Water Resources, Disasters, Climate, Ecological Forecasting, and Human Health & Air Quality.
Here are a few of the science questions that PACE will help answer:
How is Earth changing and what are the consequences for life in our ocean?
How does the Earth system respond to natural and human-induced changes?
What are the consequences of changes in the Earth system for humans?
How well can we predict future changes to the Earth system?
How are ocean ecosystems changing?
How might changes to ocean ecosystems and biodiversity affect our planet?
How do tiny airborne particles and liquids – known as "aerosols" – influence the ocean?
What are the long-term changes in aerosol and cloud properties?
How are these properties related to variations in climate?
PACE will be NASA's most advanced global ocean color and aerosol mission to date
PACE will add to climate data records while unveiling new insights on life in our ocean
PACE will add value to our everyday lives (e.g., Harmful Algal Bloom forecasts)
Ship and airborne studies being conducted worldwide are setting the stage for PACE