Understanding the exposure of the nation’s living marine resources such as shellfish and corals to changing ocean chemistry is a primary goal for the NOAA OAP. Repeat hydrographic surveys, ship-based surface observations, and time series stations (mooring and ship-based) in the Atlantic, Pacific, and Indian Oceans have allowed us to begin to understand the long-term changes in carbonate chemistry in response to ocean acidification.
When the ocean absorbs carbon dioxide, chemical reactions create hydrogen ions that act like free agents, able to react with other compounds. Two ways we track ocean acidification are through pH and total alkalinity (TA). pH is a measure of how many free hydrogen ions are in the seawater. The more carbon dioxide in the ocean, the more these free agents are created, causing lower pH (more acidic).
The partial pressure of CO2 (pCO2) tells us how much carbon dioxide is in seawater. This information helps us understand ocean carbonate chemistry and biological productivity in the region. pCO2 increases when the ocean absorbs more CO2 from the atmosphere with elevated emissions.
Alkalinity is the ocean’s buffering system against increasing acidity. Total alkalinity is a measure of the concentration of buffering molecules like carbonate and bicarbonate in the seawater that can neutralize acid.
Dissolved inorganic carbon (DIC) tells us how much non-biological carbon is in seawater. Inorganic carbon comes in three main forms that we measure for DIC: carbon dioxide (CO2), bicarbonate (HCO3-), and carbonate (CO32-). Understanding DIC can help us determine the balance of carbonate forms in the ocean and the likelihood of ocean acidification.
There are currently 19 OAP-supported buoys in coastal, open-ocean and coral reef waters which contribute to NOAA's Ocean Acidification Monitoring Program, with other deployments planned.
Currently, there are two types of floating devices which instruments can be added in order to measure various ocean characteristics - buoys and wave gliders. Buoys are moored, allowing them to remain stationary and for scientists to get measurements from the same place over time. The time series created from these measurements are key to understanding how ocean chemistry is changing over time. There are also buoys moored in the open-ocean and near coral reef ecosystems to monitor the changes in the carbonate chemistry in these ecosystems. The MAP CO2 sensors on these buoys measure pCO2 every three hours.
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Research cruises are a way to collect information about a certain ecosystem or area of interest.
For decades, scientists have learned about physical, chemical and biological properties of the ocean and coasts by observations made at sea. Measurements taken during research cruises can be used to validate data taken by autonomous instruments. One instrument often used on research cruises is a conductivity, temperature, and depth sensor (CTD), which measures the physical state of the water (temperature, salinity, and depth). The sensor often goes in the water on a rosette, which also carries niskin bottles used to collect water samples from various depths in the water column. Numerous chemical and biological properties can be measured from water collected in niskin bottles.
Ships of Opportunity (SOPs) or Volunteer Observing Ships (VOSs) are vessels at sea for other reasons than ocean acidification studies, such as commercial cargo ships or ferries.
The owners of these vessels allow scientific instrumentation that measures ocean acidification (OA) parameters to be installed and collect data while the ship is underway. This allows data on ocean chemistry to be collected in many remote areas of the world's ocean, such as high latitude waters, long distances from land (e.g. mid-basin waters), and places not easily accessible by research cruises. These partnerships have greatly increased the spatial coverage of OA monitoring world-wide. To learn more, check out the Ships of Opportunity programs established by the NOAA Pacific Marine Environmental Laboratory (PMEL) and the NOAA Atlantic Oceanographic Marine Laboratory (AOML).
Scientists at the NOAA Pacific Marine Environmental Laboratory (PMEL) are working with engineers at Liquid Robotics, Inc. to optimize a Carbon Wave Glider.
This instrument (pictured above) can be driven via satellite from land. Carbon Wave Gliders can be outfitted with pCO2, pH, oxygen, temperature and salinity sensors, and the glider’s equipment takes measurements as it moves through the water. The glider’s motion is driven by wave energy, and its sensors are powered through solar cells and batteries, when needed.
NOAA’s Coral Reef Conservation Program (CRCP) in partnership with OAP is engaged in a coordinated and targeted series of field observations, moorings and ecological monitoring efforts in coral reef ecosystems.
These efforts are designed to document the dynamics of ocean acidification (OA) in coral reef systems and track the status and trends in ecosystem response. This effort serves as a subset of a broader CRCP initiative referred to as the National Coral Reef Monitoring Plan, which was established to support conservation of the Nation’s coral reef ecosystems. The OAP contributes to this plan through overseeing and coordinating carbonate chemistry monitoring. This monitoring includes a broadly distributed spatial water sampling campaign complemented by a more limited set of moored instruments deployed at a small subset of representative sites in both the Atlantic/Caribbean and Pacific regions. Coral reef carbonate chemistry monitoring is implemented by researchers at the NOAA Atlantic Oceanographic & Meteorological Laboratory (AOML) and NOAA's PIFSC Coral Reef Ecosystems Division.
Coastal Maine supports valuable lobster, clam, oyster and other shellfish industries that comprise >90% of Maine’s record $616M landed value last year. Earlier monitoring efforts in Maine and New Hampshire have documented periods of unusually acidic conditions in subsurface waters of Maine’s estuaries, which may be driven by episodic influxes of waters from the Gulf’s nutrient-rich, highly productive coastal current system. Sources of acidity to the estuaries also include the atmosphere, freshwater fluxes, and local eutrophication processes, all modulated by variability imparted by a number of processes.This project is a data synthesis effort to look at long-term trends in water quality data to identify the key drivers of acidification in this area. Extensive data sets dating back to the 1980s (including carbonate system, hydrography, oxygen, nutrients, and other environmental variables) will be assembled, subjected to QA/QC, and analyzed to assess acidification events in the context of landward, seaward and direct atmospheric sources, as may be related to processes operating on tidal to decadal timescales. Such analyses are requisite for any future vulnerability assessments of fishery-dependent communities in Maine and New Hampshire to the effects of coastal acidification.
Whether you arrive on the Olympic Peninsula by land, sea, or air, you sense its remote, rugged and vast environment immediately. The Olympic Coast is home to productive waters which sustain thriving marine and coastal communities that have long supported the region’s tribal peoples. Ocean waters quickly deepen just offshore, boasting canyons which extend almost a mile below the surface – and have yet to be fully explored.
The Surface Ocean CO2 Atlas (SOCAT, www.socat.info) is a synthesis activity by the international marine carbon research community (>100 contributors). SOCAT version 4 has 18.5 million quality-controlled, surface ocean fCO2 (fugacity of carbon dioxide) observations with an accuracy of better than 5 μatm from 1957 to 2015 for the global oceans and coastal seas. Automation of data upload and initial data checks speeds up data submission and allows annual releases of SOCAT from version 4 onwards. SOCAT enables quantification of the ocean carbon sink and ocean acidification and evaluation of ocean biogeochemical models. SOCAT represents a milestone in research coordination, data access, biogeochemical and climate research and in informing policy.