june 2010 ams broadcasters meeting
TRANSCRIPT
Challenges to Accurate Measurement of Greenhouse Gas Emissions
Allan C. Eustis National Institute of Standards & Technology
AMS Broadcast Conference Miami Beach, Fla.
June 27, 2010
“To measure is to know.”Lord Kelvin
Metrology & Meteorology
Quantification of Gas Properties
Greenhouse Gas Measurement Research Activities
Early NIST: Founded 1901 as the National Bureau of Standards
U.S. Becomes a Signatory to the Treaty of the Metre 1879
Nascent electrical industry needed standards
American measuring instruments sent abroad for calibration
Consumer products and construction materials uneven in quality and reliability
Eight different “authoritative’ values for the gallon
Bureau of Standards Established by Congress in 1901
• Authority Given to Congress for Weights and Measures by the U.S. Constitution
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Early NIST:Need for Standards 1904 Baltimore Fire
U.S. Becomes a Signatory to the Treaty of the Metre 1879
Nascent electrical industry needed standards
American measuring instruments sent abroad for calibration
Consumer products and construction materials uneven in quality and reliability
Eight different “authoritative’ values for the gallon
Bureau of Standards Established by Congress in 1901
• Authority Given to Congress for Weights and Measures by the U.S. Constitution
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Early NIST:Need for Standards 1904 Baltimore Fire
600 Different Fire Hydrant couplings Across the US
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NIST Today:
Mission:To promote U.S. innovation and industrial competitiveness by
advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life
Major Assets• ~ 2,900 staff members• ~ 2600 associates and facilities users• ~ 1,600 field staff in partner org.• ~ 400 NIST staff serving on
1,000 national and internationalstandards committees
Major Programs• NIST Laboratories• Baldrige National Quality Program• Manufacturing Extension Partnership• Technology Innovation Program
The NIST Laboratories
Metrology: “Roads and Bridges” of Science and Trade
Groundbreaking research tools that foster progress in new fields – quantum information, nanotechnology, bioscience
Better measurement methods to ensure the quality of productsand satisfy regulatory needs– Smart Grid
Performance measures to ensure accurate technology comparisons
Standards and reference materials to ensure fairness and safety in international trade
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NIST GHG & Climate Change Measurements & Standards Activities• Climate change is a major issue for the U.S. and the World and
greenhouse gas emissions a major driver. • Measurement results of undisputable quality and scientific
integrity are needed to inform effective mitigation strategies both nationally and internationally.
• Determination of greenhouse gas amounts emitted to and removed from the atmosphere is needed at improved levels of accuracy.
• Climate change observations require improved calibration capabilities
• NIST measurement science research seeks to improve measurements and standards for greenhouse gas emissions and offset determination using surface and satellite-based methods
Ssun
UV & Visible Radiation
Thermal Radiation
The Quantitative GHG Emissions Monitoring, Reporting, and Validation Challenge
Top – DownBottom – Up
• Electricity Gen.
• General Industrial Energy Generation
0.005 – 0.05 kmStationary Sources
Continuous Emissions Monitoring Technology
• Gas Concentration. Standards
• Stack Gas Velocity Measurement
Measurement Tools, Standards Technologies & Methodologies
10 – 100 kmRegional
100 – 1000 kmInternational
Atmospheric Monitoring• Satellite Observations
• Radiometry• Optical Spectral Reference Data
• Surface-based Networks• Gas Conc. Standards• Wind Velocity Standards
Transport Fueling
Estuaries & Coastal Ocean
Single Point Measurements• Optical Reference Data• Chemical Meas. Standards
Remote Measurements• Optical Spectral Ref. Data• Advanced Measurement Tools &
Methodologies
Forests & Woodlands
Landfills
Distributed or Area Sources and Sinks
Agriculture
0.5 – 5 km
Size or Extent (Source or Measurement Approach)
Size and Scope of Climate Change MeasurementsImpacts on Monitoring, Reporting, and Verification
Top – DownBottom – Up
• Electricity Gen.
• Industrial Energy Generation
0.005 – 0.05 km
Measurement Tools, Standards, Technologies & Methods
10 – 100 km
Regional International
Agriculture
Transport Fueling
Distributed or Area Sources
Estuaries & Coastal Ocean
0.5 – 5 km
Forests & Woodlands
Size or Extent
+ =Landfills
100 – 1,000 km
A Primary Technical Measurement Challenge GHG Inventory Determination and Acceptance
Internationally• Quantification of GHG Mass Transfers To & From the Atmosphere
– Always require:• Determination of GHG concentration at a point source or across an area• GHG transport rate – Directional
– Emissions – to the atmosphere– Removals – from the atmosphere
GHG Mass Flowrate = Total Gas Mass Flowrate * GHG Concentration
Mass Flowrate• Confined flows in stacks
• Gas impact velocity and ultrasonic methods are predominant
• Quantification over geographical areas • Wind field characterization – 3D problem• Directional and periodic
GHG Concentration• Confined flows in stacks
• Point sampling• NIST for the Acid Rain Program
• Quantification over geographical areas • Dispersed, gradients, and variable• Dimensions up to several square kilometers
SSun
Thermal Radiation
UV & Visible Radiation
The Earth’s Radiative Balance& The NIST Climate Program
• Infrared & Microwave Standards• Greenhouse Gas Measurements
Point and Area SourcesRegional reconciliation of inventories with atmospheric measurements
• Gas Concentration Standards• Spectroscopy and Kinetic Data• Temperature Standards• Humidity and Pressure Standards
• Reflective Aerosols Data• Black Carbon Aerosols Data• Reflectance Standards• Ocean Color Standards
• Lamp Irradiance Standards• Aperture Area Measurements• Absolute Detector Standards
ρEarth
εAtm; TAtm
Satellite Calibrations &
Standards
NIST/NASA Collaboration: The Orbiting Carbon ObservatoryImproved CO2 Determination in the Atm. Column
CO2 observations from orbitat the <0.5% (2 ppm) level
requires world class spectroscopic reference
data for CO2 and the O2 A-band.
In the past two years NIST has completed six projects in support of NASA’s OCO. This work has produced the lowest uncertainty spectroscopic line
parameter measurements in the world on the O2 A-band.
Diatomic oxygen (O2) provides atmospheric path lengths in
remote sensing measurements.
NIST Program Components• Point Source Metrology
– Continuous Emission Mon. Test Bed• Distributed Source Metrology
– Flux Measurement Tools– Emission Dispersion Analysis– Field Reference Site
• GHG Measurements, Standards, Ref. Data, and Tools
– Gas Concentration Standards– Atmospheric Lifetime References– Spectroscopic Reference Data– Documentary Standards &
Assessment Methodologies• GHG Inventory & Regional Emissions
Profile Methodologies– Region Criteria Development– Stakeholder Identification– Demo. Project Planning and Imple.
• Advanced, Field-Deployable Detection Technologies– Frequency Comb IR Sources– Fieldable Atmospheric Monitoring Tech.
• Satellite Calibration– Optical Reflectance and Transmittance
Standards– Microwave Standards– Thermal Infrared Standards– Scene Generation
• Aerosol Measurement Science– Black Carbon Morphology– Black Carbon Bulk Properties– Black Carbon Optical Properties– VOC Aerosol Formation Mechanisms
ARRA Research Grants• Measuring Greenhouse Gas Emissions by Inverse Methods:
A Pilot Program - Scripps & LLNL• Development, Improvement, and Assessment of the Accuracy of Aircraft-Based
Mass Balance Measurements of the Integrated Urban Emission Fluxes of Greenhouse Gases – Purdue, Univ. Colo., and Penn State Univ.
• Multi-wavelength LIDAR System to Characterize Atmospheric Composition & Chemistry – Michigan Aerospace
Gas Concentration StandardsReference Materials• SRM 1720, Global Background Air (2010)
• Certified for CO2, CH4, N2O, CO
•CFC SRM (2011)• To be certified for CFCs, SF6, VOCs
Methods• NOAA collaboration on urban tower air sample
collection• Track effectiveness of mitigation efforts of
major metropolitan area
International Engagement• CCQM Key Comparisons
• Atmospheric CH4 (2014)• Atmospheric CO2 (2011)• Atmospheric CFC/HFC (2011)• Atmospheric N2O (2013)
• Biosphere indicator gases• Requested by World Metrology Organization, Global Atmospheric
Watch program• With national metrology institutes: NPL (UK),
VSL (Netherlands), and KRISS (Korea)
Critical to:• CEMS• Atmospheric Monitoring and
the Decadal Observation Series Inherent to Climate Studies of the Atmosphere
Standards Framework for Climate ObservationsWMO-BIPM Partnership to Facilitate Use of the SI
Traceability in Climate Observations - 2002
World Meteorological Organization (WMO)
International Committee for Weights and Measures (CIPM)
“...have agreed to work together to ensure that data related in particular to measurements of state and composition of atmosphere and water resources, coming from the programmes organized under the auspices of the WMO, are properly based on units traceable to the SI through the procedures of the CIPM MRA and the Technical Regulations of the WMO.”
Treaty of the Metre Organizations• CIPM – International Committee on Weights and Measures
• BIPM – International Bureau of Weights and Measures
Workshop on Quantification of GHG Area Sources and Sinks: Summary of Priority Research Targets
Instrumentation and Technology– Components for High Performance Remote Sensing Systems
• Better detector technology for λ≥1100nm; higher quantum efficiency, larger active areas, high bandwidths, lower NEP, extension to λ≥ 2500nm
• Higher power, more spectrally pure, single-frequency diode lasers (DFBs or DBRs) to serve as seed sources for pulsed lasers/OPO or as sources for open-path sensors
– Compact, cost-effective DIAL Lidar (greenhouse gases: CO2, CH4, N2O)• Better understanding of required application performance (sources/sinks,
local/regional scales)• Targeted Lidar designs (total error budgets, key components)
– Smaller and Cheaper Measurement Technology• Reduction in size, weight, power, cost, complexity of existing
measurement techniques ( alternative spectroscopic techniques, better battery technology, streamlined electronics & data acquisition, ability to sample accurately & precisely under ambient conditions)
Workshop on Quantification of GHG Area Sources and Sinks: Summary of Priority Research Targets
Instrumentation and Technology– Spectroscopic Data to Support GHG Flux and Concentration
Measurements• Extremely precise (0.1%) spectroscopic parameters in support of
OCO satellite retrievals of O2 and CO2 (1.6m and 2.0m) including T and P dependence
• Development of 2µ Lidar sensors, optical sensors to monitor isotopic ratios in real time
– Long-term Dense Network of Continuous FencelineMonitors/Anthropogenic• Develop accurate, cost effective fenceline monitors in parallel
– Long-term Dense Network of GHG Mole Fraction Measurements• Accelerate development of low cost, robust, accurate instruments• Transport model improvements based on measured wind profiles,
boundary layer height
Workshop on Quantification of GHG Area Sources and Sinks: Summary of Priority Research Targets
Modeling• GHG Testbed for Model Validation
– Capability of models to reproduce a known source; influence of weather on models; differences between multiple point sources vs. a true area source and how differences affect models; well-controlled GHG source that can simulate a variety of source types; field campaigns for model validation
• Protocols for Emissions Quantification Measurements and Models– Identify possible combinations of measurements and models for quantifying emissions;
assess and develop protocols for appropriate techniques (sensors and models)• Optimal Sampling Strategies for Small Scale GHG Emission Measurements
– Explore sensitivity of sampling methods using numerical simulation; identify characteristic scales of temporal and spatial variability in actual sources
• GHG Emission Simulation– Compare IR emissions for simulated measurements with simulators of whole systems;
characterize whole system error and uncertainty; simulation of complete source (µm environment, point sources vs. distributed/area)
NIST Workshop – June 2 & 3, Scripps Institution of OceanographyGREENHOUSE GAS EMISSIONS QUANTIFICATION AND VERIFICATION STRATEGIES
AWMA Symposium – Sept. 8 to 10, Washington, DC2nd AWMA Greenhouse Gas Measurement Symposium
NIST Program SummaryMeasurements Promote:• Fairness & equity in GHG
accounting and markets• Efficiency in the generation
& use of GHGs• Equitable usage of GHG
offsets• The quality of greenhouse
gas inventories that furnish the foundation for policy and regulatory decisions
• Science-based GHG mitigation caps.
• A basis for reconciliation of determinations of GHG inventories from the top-down and the bottom-up
Traceability to the SI:• Allows comparisons to be
made independent of time or locale
• Improves measurement accuracy
• Provides confidence in the accuracy of measurements
• Helps contractors understand and meet agency requirements, protecting contractor and customer
• Ensures the quality of climate data records that furnish the foundation for policy and regulatory decisions
Economic Valuation of GHGs will Drive Greater Accuracy Needs
C & W Music Titles You May Have Missed
“The Pint of No Return”“If Love were Oil, I’d be a Quart Low”(conversion to metric)“If Love were Oil, I’d be a Half Liter Low”
“The Bridge Washed Out; I Can’t Swim &My Baby’s on the Other Side”
GHG Point Source: Pulverized Coal Power Plant
Flue Gas
Velocities of Fluid Structures in an Elbow
• A simple geometry can create a complex velocity vector field – Counter rotating vortices
• Velocity field is not ideal for flow measurement applications
Point Source MetrologyNIST Large Fire Facility: 1:100 scale stack model
measure flow properties & CO2
concentration in stack
Heat Release Quantification for Many Materials & Structures
Distributed GHG Emissions Sources and Sinks (1 – 5 km Geographical Areas)Optical Remote Sensing Technologies
GHG Mass Flowrate
LIDAR Doppler
Velocimeter
Hyperspectral ImagingDetermines Plume Cross-
section & Extent
GHG ConcentrationDIAL: Differential Absorption LIDAR
x
y
z
φ
cross sectional area Acs
Emission
Sou
rce
Lidar – Related Implementation Technologies• Available for ~2 decades
• Significant technological advances by telecom technology industry in optical fibers and solid state lasers and amplifiers
• Platform for development of suitcase-sized systems
Heterodyne DIAL Measurement Greenhouse Gas Area Source & Sink Mass Flux
CH4
CO2
N2O (x1000)
1.646 1.590λ / μm
H2O
• Dual beam heterodyne approach • Common mode noise rejection
• Simultaneous sideband approach
On/Off - 10 GHz
3 µm
1.58-1.65 µm
Cavity Lock*
P = 5 mJ (PPLN=20 mJ)Δν=190 MHz (transform limited)
LiNbO3
High Accuracy Spectroscopic Reference DataO2 A Band (~765 nm)
Frequency-stabilized cavity ring-down spectrometer
frequency -stabilizedreference laser
cw probe laser
cavity stabilization servo
pztoptical resonator
decay signalfrequency -stabilizedreference laser
cw probe laser
cavity stabilization servo
pztoptical resonator
decay signal
200 MHz
frequency
absorption spectrum
stabilized comb of resonant frequencies
200 MHzabsorption spectrum
transition index
NIST• Quantified a correction required to
accurately describe line intensities in the O2 A-band
• Accurate absorption line shape measurements augmented with high accuracy absorber number density determination reduced line intensity uncertainties from 2% to 0.3%
New Measurement Technologies
Self-calibrating instrument for measuring absolute gas concentrations and aerosol absorption coefficient.
Photoacoustic Spectrometer
NIST Radiometric Measurements
and Standards Capabilities
Supporting Satellite Calibrations
and
Performance Evaluation
Liquid He @ 2K
LN2
• POWR provides optical power measurement capability to the 0.01% (k = 2) level
• Primary Standard for satellite radiometric observing schemes
NIST Primary Optical Watt Radiometer (POWR)Optical Measurements are Traceable to the SI through the Electrical Watt
Field or Satellite measurements required near the level where standards are available are often a
significant challenge to realize.
Measurements Require Quality and Accuracy
Vendor NIST Vendor NIST
High Resolution Infrared Radiation Sounder (HIRS) on the Polar-Orbiting Operational Environmental Satellites (POES)
optical filter center wavelength Temperature sensitivity measurement
ΔT > 10 K ΔT up to 0.5 K
Resolves ~ 10 Kelvin Atmospheric Temperature Measurement Discrepancy
Can GHG Observation Networks and Inverse Modeling Be Applied to Verification
• Can GHG quantification and SourceID Reach Spatial Resolutions of ~1 km?
• What additions to surface-based networks are needed?
– Mesonets – Installed Observing Networks• Public/Private partnership opportunity
– GHG Concentration instrumentation needs– Accurate – 1 ppm of ~400 ppm (CO2)– Robust - Fieldable
» No calibration gases for routine operation– Low-cost
– Inverse Modeling Resolution• Boundary layer turbulence-induced limits –
velocity dispersive relationships• Accuracy of weather data• Optimize number of observing points
Obs.Station
Observing Network
Inverse modeling combined with weather data and atm. dispersion
models regresses observed concentrations to their source
AGAGE – NASA Supported, Scripps-MIT Lead
NOAA – Tall Towers System & CarbonTracker
Workshop on Quantification of GHG Area Sources and Sinks: Summary of Priority Research Targets
Defining the Measurement Problem– Definition and Clarification of Regulatory Needs and Requirements
• Conduct one or more emissions measurement pilot programs with partnership among stakeholder groups
• Design measurement networks for long-term monitoring with input from all stakeholder groups
– Pilot Study: Methodological Test and Comparison of Techniques• Field program to quantify emission of multiple gases from a single
large metropolitan area using multiple approaches• Similar activity for offsets and management
