Sustaining Ocean Observations

to Understand Future Changes

in Earth’s Climate

DIVISION OF EARTH AND LIFE STUDIES

Briefing to the Ocean Studies Board

November 14, 2017

Committee Co-chairs:

Mary M. Glackin, The Weather Company

Robert A. Weller, Woods Hole Oceanographic Institution

Study Committee

MARY M. GLACKIN, Co-Chair, The Weather Company, an IBM Business, Washington, D.C.

ROBERT A. WELLER, Co-Chair, Woods Hole Oceanographic Institution, Massachusetts

EDWARD A. BOYLE, Massachusetts Institute of Technology, Cambridge

ROBERT B. DUNBAR, Stanford University, California

ROBERT HALLBERG, NOAA’s Geophysical Fluid Dynamics Laboratory, Princeton, New Jersey

PATRICK HEIMBACH, University of Texas at Austin

MARK MERRIFIELD, University of Hawaii at Manoa

DEAN ROEMMICH, Scripps Institution of Oceanography, La Jolla, California

LYNNE D. TALLEY, Scripps Institution of Oceanography, La Jolla, California

MARTIN VISBECK, GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany

Staff

SUSAN ROBERTS, Director, Ocean Studies Board

EMILY TWIGG, Associate Program Officer, Ocean Studies Board

APRIL MELVIN, Associate Program Officer, Board on Atmospheric Sciences and Climate

ALLIE PHILLIPS, Senior Program Assistant, Ocean Studies Board

Study Context

• The oceans play a substantial role in climate: The ocean absorbs 90% of the

surplus heat, about 30% of the CO2 associated with human activities, and

receives close to 100% of fresh water lost from land ice.

• Measurements of ocean climate variables are needed to test and improve

climate models

• Observations of climate

variables must be

sustained over long time

scales

• Concerns regarding

sustained funding for

long-term observing

NOAA

Statement of Task Maintaining long-term, continuous, ocean-data records for understanding, monitoring changes in, and

modeling climate changes are essential, yet, challenging. An ad hoc committee will consider processes for

identifying and characterizing the most critical, long-term ocean observations and identify

limitations of the current approaches.

When considering the various processes for selecting and characterizing high-priority, long-term ocean

observations, the committee will discuss potential factors such as:

• Accuracy, precision, frequency, and spatial resolution of observations;

• Duration of observations (e.g., what criteria would be used to determine when observations should be

sustained at high priority, are no longer needed for a given parameter or when an observation would be

superseded by a different type of observation, for example through a new/different technology);

• Inherent value and/or tradeoffs of increasing multidisciplinary observations across a limited number of

networks/platforms vs initiating additional observing systems;

• Complementarity of an observation to another set of observations (or network); and,

• Current or near-future technology that could be used to develop a more cost-effective observational

system.

The committee's report will identify challenges to maintaining long-term observations and suggest

avenues for potential improvement. During the study, the committee will convene a workshop to gather

expert opinions on the process for prioritizing long-term, ocean climate observations and discuss international

approaches to selecting and sustaining ocean observations, as well as other topics that are important for the

design of sustainable, long-term ocean observing systems.

Study Activities

• An information gathering workshop held in Washington, DC

with members of the U.S. and international ocean observing

community.

• Discussions with representatives from foundations and the

private sector to explore their contribution and potential for

further involvement in ocean observing.

Three Global Budgets

• The committee focused on three global budgets: heat, carbon, and

fresh water. – Sea level rise is described as a reflection of the heat and fresh water

budgets

• Sufficient understanding of climate requires the ability to reconcile the

inputs to, exchanges among, and storage of climate elements within the

ocean, land, and atmosphere.

• Observations allow for accurate characterization of the key processes used

to close the budget within a model, critical to projecting future changes.

Heat Budget

Budget closure requires observations of:

• ocean heat content

• air-sea heat exchange

• heat transport by ocean currents

• mixing

In situ heat content estimates. Johnson et al.

2016. Bull. Amer. Meteor. Soc. 97(8)

Central to understanding the

delayed warming of the

Earth’s surface temperature

Carbon Budget

Budget closure requires

observations of:

• either surface water partial

pressure of CO2 (pCO2) or pH,

• total dissolved CO2

• alkalinity

In situ carbon estimates. Doney et al. 2009. Annual

Review of Marine Science 1, with data from Bates et al.

2014. Oceanography 27(1)

Helps predict future

atmospheric CO2

concentrations and

informs the rate at which

ocean acidification

increases.

Fresh Water budget

Budget closure requires observations of:

• salinity

• temperature

• sea ice

• velocity and mixing

• fluxes of freshwater into and out of

the ocean--precipitation, continental

and ice sheet runoff, and evaporation

Trends in surface salinity associated with

precipitation and evaporation. Rhein et al. 2013.

IPCC AR5

Changes in salinity reflect

changes in the global hydrologic

cycle. Salinity and temperature

determine seawater density, which

sets the vertical stratification of

the ocean.

Sea-Level Change

• Heat content provides estimates of

rates of thermosteric sea-level rise

• Fresh water input from land ice

contributes to sea-level rise

• Ocean current observations are

required to evaluate the transport of

heat and salt, and for their

contributions to regional sea-level

change.

Trends in global sea level measured by satellite

(black, blue) and Argo floats (red). Leuliette and

Nerem. 2016. Oceanography 29(4)

Reflects the heat and

fresh water budgets

Atlantic Meridional Overturning

Circulation

Overturning circulation pathways are a critical property of the climate system--redistributing and storing heat and carbon absorbed from the atmosphere.

Historic observations have been limited, leading to misunderstanding of the natural variability and complex processes.

Regular observations began in 2004,challenging notions of a simplified conveyor belt and also showed that natural variability occurred on shorter timescales.

Further observations will be needed to contribute to the mechanistic understanding of the MOC.

Benefits beyond Climate

• An ocean climate observing system also benefits many

areas of science, commerce, and safety

– Weather forecasting including hurricane and El Niño forecasting

– Marine resource management including fisheries productivity and

ocean acidification

– Data products for safe and optimal shipping and fishing

NOAA NASA B.S. Halpern / Wikimedia Commons

Improving ocean observations

• Closing the budgets will be aided by expansion of observations into

poorly sampled regions, by the development of methods to quantify

as yet unmeasured processes, and by the deployment of new sensors

to sample biogeochemical properties and aid investigation of the

carbon budget.

NOAA

NASA

NOAA SOCCOM/Climate Central

International Coordination

Distribution of deployed in situ platforms from Sep 2017. JCOMMOPS

• Global Climate Observing

System (GCOS) coordinates in

situ and remote systems to

meet requirements for climate

observations.

• Global Ocean Observing System

(GOOS) was developed to meet

research and operational

requirements for sustained

ocean observations for

climate, as well as ocean

health and real-time services

Framework for Ocean Observing

• The committee found the Framework and the associated procedures for establishing

the Essential Ocean Variables (EOVs) are constructive for defining ongoing

requirements (precision, frequency, spatial resolution) for sustained ocean

observations and provide a solid foundation for selecting and prioritizing ocean

variables for sustained observing.

• The Framework is an ongoing process that allows for new priorities as societal and

scientific priorities change and capabilities matures.

Essential Ocean Variables

for Climate

Specification documents describe the observing platforms and sampling

requirements, dependent on the phenomena being captured, for each EOV.

Physical Variables:

• Sea state

• Ocean surface stress

• Sea ice

• Sea surface height

• Sea surface temperature

Biogeochemical Variable:

• Inorganic carbon

• Surface currents

• Subsurface currents

• Sea surface salinity

• Subsurface salinity

• Ocean surface heat flux

Readiness

level:

CONCEPT

PILOT

MATURE

Challenges and

Conclusions

International Coordination

Conclusion: The Global Ocean

Observing System organization

has effectively engaged countries

and built capacity for ocean

climate observing. A challenge

remains in obtaining global access

to national Exclusive Economic

Zones for drifting platforms

which could be addressed by

NORLC. French R/V Pourquoi Pas. Argo Program

Ocean Observing in the U.S.

• Federal activities: – Investments from individual agencies: NOAA, NSF, NASA, ONR

– The National Ocean Partnership Act (1996) established

• the National Ocean Partnership Program (NOPP),

• the National Ocean Research Leadership Council (NORLC; under the National

Ocean Policy, the NOC assumed the responsibilities of the NORLC),

• and the Ocean Research Advisory Panel (ORAP).

IOOS Organization. Interagency Ocean Observing Committee

— The Integrated Coastal and

Ocean Observing System

(ICOOS) Act (2009)

established

• the Interagency Ocean

Observations Committee

(IOOC) and the

• U.S. Integrated Ocean

Observing System (IOOS).

Need for Long-term Planning

Conclusion:

• A decadal plan for the U.S. ocean observing system would be the most

effective approach for ensuring critical ocean information is available to

understand future climate.

• Consistent with the Framework for Ocean Observing.

• Elements of a decadal plan include: identification of requirements,

assessment of the adequacy of the current system, components to be

deployed over the ten-year period, potential for technological

advancements, and an estimate of resources necessary to implement the

plan.

• NORLC could be responsible for its periodic assessment and update possibly

utilizing the IOOC and the ORAP.

Ocean Observing Workforce

Conclusion: Direct scientific involvement in sustained observing

programs, from design to implementation to analysis, synthesis, and

publication, ensures that the ocean observing system will be robust in

terms of data quality, incorporation of new methods and technologies,

and scientific analyses. Thus intergenerational succession of scientists

is critical for sustaining the observations on climate timescales. The

OCP could focus on improving career incentives for the scientific

workforce as a priority.

Building BGC Argo

floats at University of

Washington. SOCCOM

Project

Observation Technology

• The ocean is a complex environment, both technologically and logistically.

Conclusion: Declining investments

have slowed the development of new

technology, which is proven to expand

the capability, the efficiency, and

therefore the capacity of the

observing system. Philanthropic

efforts have in part filled this gap and

the OCP could encourage more support

there.

Seaglider. NOAA

Research Fleet

Conclusion: While new technology holds promise for access to the ocean, a

capable fleet of research vessels, including those with global reach, is essential

to sustaining the U.S. contribution to ocean observing.

• A fleet of global and ocean class ships is necessary for making direct

observations and for deploying and maintaining observing platforms.

NOAA Ship Ronald H. Brown. NOAA

The Way Forward

Diverse Actors

• The committee found the scientific, technical, and engineering staff at

academic and government oceanographic institutions to be essential for

developing technology, operating observing platforms, and utilizing data.

• Philanthropies are a potential partner for supporting ocean observing as many

have made substantial investments in areas such as marine technology, ocean

research, education and outreach, conservation, and exploration and

discovery, though to date have not usually invested in long-term projects.

• Given that ocean observations for climate provide a wide range of benefits to

the agricultural, shipping, fishing, insurance, and energy-supply industries,

efforts can be made to draw support for ocean observing from the

commercial sector.

Need for Partnerships

• Conclusion: An Ocean-Climate Partnership (OCP) organization

would be an effective mechanism to increase engagement and

coordination of the ocean observation science community with

non-profits, philanthropic organizations, academia, U.S. federal

agencies, and the commercial sector. Through their shared

interests in the observational data and associated products, the

OCP members could work together toward the goal of sustaining

the ocean climate observing system.

Potential New Models of Support

• Ocean climate data is needed to inform national security, economic, and

societal decisions on climate change and other ocean-related issues and,

given the inter-governmental negotiations required for participating in a

global system, responsibility for supporting the ocean observing system falls

predominantly on the federal government in the United States.

• Opportunities exist to expand partnerships and coordination with the private

and nonprofit sector.

For additional information:

Emily Twigg, ETwigg@nas.edu

Report available at: https://www.nap.edu

Sponsored by the Arthur L. Day

Fund of the National Academies

and the National Oceanic and

Atmospheric Administration