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Introducing the groundbreaking capabilities of NASA’s PACE satellite’s Ocean Color Instrument (OCI), which detects light across a hyperspectral range, enabling scientists to distinguish between different phytoplankton communities. The first image released from OCI unveils two distinct communities of microscopic marine organisms off the coast of South Africa on Feb. 28, 2024: Synechococcus in pink and picoeukaryotes in green. The image also features a natural color view of the ocean on the left panel, while the right panel displays the concentration of chlorophyll-a, a key photosynthetic pigment indicating phytoplankton presence. |
NASA’s latest Earth-observing satellite, the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite, is revolutionizing our understanding of ocean health, air quality, and the impacts of climate change by providing unprecedented measurements. Launched on Feb. 8, the satellite has undergone rigorous in-orbit testing to validate the functionality and data quality of its instruments. Following successful testing, NASA has made science-quality data accessible to the public through the mission’s official website (https://pace.oceansciences.org/access_pace_data.htm), marking a significant milestone in global environmental monitoring efforts.
PACE data is poised to catalyze significant advancements in the study of both microscopic ocean life and atmospheric particles, unlocking insights into critical issues such as fisheries health, harmful algal blooms, air pollution, and wildfire smoke. By harnessing the capabilities of PACE, scientists will delve deeper into understanding the intricate dynamics between the ocean and atmosphere, shedding light on their interplay amidst a changing climate. NASA Administrator Bill Nelson emphasized the importance of these endeavors, stating, “These stunning images are furthering NASA’s commitment to protect our home planet…PACE’s observations will give us a better understanding of how our oceans and waterways, and the tiny organisms that call them home, impact Earth. From coastal communities to fisheries, NASA is gathering critical climate data for all people.”
First light from the PACE mission marks a significant milestone in our continuous quest to deepen our understanding of our evolving planet,” stated Karen St. Germain, Director of NASA’s Earth Science Division. “Earth, predominantly covered by water, remains less explored than the moon’s surface. PACE, alongside pivotal missions like SWOT and the forthcoming NISAR, heralds a new era in Earth science, offering unprecedented insights into our planet’s complex systems.
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Introducing PACE’s OCI instrument’s multifaceted capabilities, beyond its role in ocean health assessment, it also serves as a vital tool for studying atmospheric conditions. In this groundbreaking image, the top three panels capture dust from Northern Africa transported into the Mediterranean Sea, showcasing familiar data collected by previous satellite instruments: true-color images, aerosol optical depth, and the UV aerosol index. However, the bottom two images unveil novel datasets crucial for refining climate models. Single-Scattering Albedo (SSA) reveals the fraction of light scattered or absorbed, enhancing model accuracy, while Aerosol Layer Height indicates aerosol distribution in the atmosphere, providing valuable insights into air quality dynamics. |
The Ocean Color Instrument (OCI) aboard the PACE satellite, developed and overseen by NASA’s Goddard Space Flight Center in Greenbelt, Maryland, surveys the ocean, land, and atmosphere using ultraviolet, visible, and near-infrared light. Unlike its predecessors, which could only detect a limited number of wavelengths, PACE can capture data across more than 200 wavelengths. This extensive spectral coverage enables scientists to pinpoint specific phytoplankton communities, crucial for understanding their diverse ecological roles and impacts on the carbon cycle. Moreover, PACE boasts two multi-angle polarimeters, HARP2 and SPEXone, designed to measure polarized light reflected by clouds and atmospheric particles.
These aerosols, ranging from dust to smoke to sea spray, are pivotal in shaping Earth’s climate and air quality. SPEXone, crafted by the Netherlands Institute for Space Research (SRON) and Airbus Netherlands B.V., provides hyperspectral resolution, while HARP2, developed at the University of Maryland, Baltimore County (UMBC), offers observations across four wavelengths at 60 different viewing angles, complementing each other’s capabilities.
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Early data from the SPEXone polarimeter instrument aboard PACE show aerosols in a diagonal swath over Japan on Mar. 16, 2024, and Ethiopia on Mar. 6, 2024. In the top two panels, lighter colors represent a higher fraction of polarized light. In the bottom panels, SPEXone data has been used to differentiate between fine aerosols, like smoke, and coarse aerosols, like dust and sea spray. SPEXone data can also measure how much aerosols are absorbing light from the Sun. Above Ethiopia, the data show mostly fine particles absorbing sunlight, which is typical for smoke from biomass burning. In Japan, there are also fine aerosols, but without the same absorption. This indicates urban pollution from Tokyo, blown toward the ocean and mixed with sea salt. The SPEXone polarization observations are displayed on a background true color image from another of PACE’s instruments, OCI. |
The wealth of data collected by PACE will empower scientists to assess cloud properties crucial for climate understanding and to monitor and analyze atmospheric aerosols, enhancing public awareness of air quality dynamics. Furthermore, these datasets will shed light on the intricate interactions between aerosols and clouds, influencing cloud formation processes critical for refining climate models with greater accuracy.
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Introducing early insights from PACE’s HARP2 polarimeter, which recently obtained data on clouds along the west coast of South America on Mar. 11, 2024. This pioneering polarimetry data offers valuable insights into cloud properties, including the composition of cloud droplets contributing to phenomena like the cloudbow—a rainbow formed by sunlight reflecting off cloud droplets rather than rain droplets. Scientists can leverage this data to understand how clouds react to human-induced pollution and other aerosols, as well as to quantify the size of cloud droplets, enhancing our comprehension of atmospheric processes. |
HJeremy Werdell, PACE project scientist at NASA Goddard, expressed the long-awaited fulfillment of a dream spanning over two decades upon witnessing the imagery captured by PACE’s instruments. Werdell emphasized the exceptional quality of the data, enabling its public distribution merely two months after launch—an achievement he credits to the dedicated team. Highlighting the transformative potential of these data, Werdell noted their significance in enhancing everyday life through insights into air quality and aquatic ecosystem health, while also shaping our evolving perception of Earth.
Managed by NASA Goddard, the PACE mission saw the spacecraft and ocean color instrument built and tested by the same entity. The Hyper-Angular Rainbow Polarimeter 2 (HARP2) originates from the University of Maryland, Baltimore County, while the Spectro-polarimeter for Planetary Exploration (SPEXone) stems from a Dutch consortium led by the Netherlands Institute for Space Research, Airbus Defence, and Space Netherlands.
