Challenges to Accurate Measurement of Greenhouse Gases

1. 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

2. “To measure is to know.”
Lord Kelvin
Metrology & Meteorology
Quantification of Gas Properties
Greenhouse Gas Measurement Research
Activities

3. 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
National Archives
Bureau of Standards Established by
Congress in 1901
• Authority Given to Congress for
Weights and Measures by the U.S.
Constitution

4. 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
Enoch Free Library
Weights and Measures by the U.S.
Constitution

5. Early NIST:Need for Standards
1904 Baltimore Fire
600 Different Fire Hydrant couplings
Across the US
Enoch Free Library

6. 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 Major Programs
• ~ 2,900 staff members • NIST Laboratories
• ~ 2600 associates and facilities users • Baldrige National Quality Program
• ~ 1,600 field staff in partner org. • Manufacturing Extension Partnership
• ~ 400 NIST staff serving on • Technology Innovation Program
1,000 national and international
standards committees

7. The NIST Laboratories

8. 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 products
and satisfy regulatory needs
– Smart Grid
Performance measures to ensure
accurate technology
comparisons
© MOSCHENShutterstock
Standards and reference
materials to ensure fairness and
safety in international trade

9. 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 Ssun
emissions and offset determination
using surface and satellite-based
methods UV & Visible Radiation
Thermal Radiation

10. The Quantitative GHG Emissions Monitoring,
Reporting, and Validation Challenge
Bottom – Up Top – Down
Estuaries &
Coastal Ocean
Agriculture
Landfills
• Electricity Gen.
• General Industrial
Energy Generation
Transport Fueling
Forests & Woodlands
Stationary Sources Distributed or Area Sources and Sinks Regional International
0.005 – 0.05 km 0.5 – 5 km 10 – 100 km 100 – 1000 km
Size or Extent (Source or Measurement Approach)
Continuous Emissions Single Point Measurements Remote Measurements Atmospheric Monitoring
Monitoring Technology • Satellite Observations
• Optical Reference Data • Optical Spectral Ref. Data
• Radiometry
• Gas Concentration. • Chemical Meas. Standards • Advanced Measurement Tools &
Standards Methodologies • Optical Spectral Reference Data
• Stack Gas Velocity • Surface-based Networks
Measurement • Gas Conc. Standards
• Wind Velocity Standards
Measurement Tools, Standards Technologies & Methodologies

11. Size and Scope of Climate Change Measurements
Impacts on Monitoring, Reporting, and Verification
Bottom – Up Top – Down
Estuaries &
Coastal Ocean
Agriculture Landfills
+ =
• Electricity Gen.
• Industrial Energy
Generation
Transport Fueling
Forests & Woodlands Regional International
Distributed or Area Sources
0.005 – 0.05 km 10 – 100 km 100 – 1,000 km
0.5 – 5 km
Size or Extent
Measurement Tools, Standards, Technologies & Methods

12. 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 GHG Concentration
• Confined flows in stacks • Confined flows in stacks
• Gas impact velocity and ultrasonic • Point sampling
methods are predominant • NIST for the Acid Rain Program
• Quantification over geographical • Quantification over geographical
areas areas
• Wind field characterization – 3D problem • Dispersed, gradients, and variable
• Directional and periodic • Dimensions up to several square kilometers

13. The Earth’s Radiative Balance
& The NIST Climate Program
UV & Visible Radiation
Thermal Radiation
Satellite
Calibrations &
Standards
SSun
ρEarth
• Lamp Irradiance Standards
• Aperture Area Measurements εAtm; TAtm
• Absolute Detector Standards
• Infrared & Microwave Standards
• Greenhouse Gas Measurements
• Reflective Aerosols Data Point and Area Sources
• Black Carbon Aerosols Data Regional reconciliation of inventories
with atmospheric measurements
• Reflectance Standards • Gas Concentration Standards
• Ocean Color Standards • Spectroscopy and Kinetic Data
• Temperature Standards
• Humidity and Pressure Standards

14. NIST/NASA Collaboration:
The Orbiting Carbon Observatory
Improved CO2 Determination
in the Atm. Column
CO2 observations from orbit
at the <0.5% (2 ppm) level
requires world class
spectroscopic reference
data for CO2 and
the O2 A-band.
Diatomic oxygen (O2) provides
atmospheric path lengths in
remote sensing measurements.
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.

15. NIST Program Components
• Point Source Metrology • Advanced, Field-Deployable Detection
– Continuous Emission Mon. Test Bed Technologies
• Distributed Source Metrology – Frequency Comb IR Sources
– Flux Measurement Tools – Fieldable Atmospheric Monitoring Tech.
– Emission Dispersion Analysis • Satellite Calibration
– Field Reference Site – Optical Reflectance and Transmittance
• GHG Measurements, Standards, Standards
Ref. Data, and Tools – Microwave Standards
– Gas Concentration Standards – Thermal Infrared Standards
– Atmospheric Lifetime References – Scene Generation
– Spectroscopic Reference Data • Aerosol Measurement Science
– Documentary Standards & – Black Carbon Morphology
Assessment Methodologies – Black Carbon Bulk Properties
• GHG Inventory & Regional Emissions – Black Carbon Optical Properties
Profile Methodologies – VOC Aerosol Formation Mechanisms
– Region Criteria Development
ARRA Research Grants
– Stakeholder Identification
• Measuring Greenhouse Gas Emissions by Inverse Methods:
– Demo. Project Planning and Imple.
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

16. Gas Concentration Standards
Reference 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
Critical to: International Engagement
• CEMS • CCQM Key Comparisons
• Atmospheric Monitoring and • Atmospheric CH4 (2014)
the Decadal Observation • Atmospheric CO2 (2011)
Series Inherent to Climate
• Atmospheric CFC/HFC (2011)
• Atmospheric N2O (2013)
Studies of the Atmosphere
• Biosphere indicator gases
• Requested by World Metrology Organization, Global Atmospheric
Watch program
• With national metrology institutes: NPL (UK),
VSL (Netherlands), and KRISS (Korea)

17. Standards Framework for Climate Observations
WMO-BIPM Partnership to Facilitate Use of the SI
Traceability in Climate Observations - 2002
World Meteorological International Committee for
Organization (WMO) 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

18. 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)

19. 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 Fenceline
Monitors/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

20. 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 Oceanography
GREENHOUSE GAS EMISSIONS QUANTIFICATION AND VERIFICATION
STRATEGIES
AWMA Symposium – Sept. 8 to 10, Washington, DC
2nd AWMA Greenhouse Gas Measurement Symposium

21. NIST Program Summary
Measurements Promote: Traceability to the SI:
• Fairness & equity in GHG • Allows comparisons to be
accounting and markets made independent of time or
• Efficiency in the generation locale
& use of GHGs • Improves measurement
• Equitable usage of GHG accuracy
offsets • Provides confidence in the
• The quality of greenhouse accuracy of measurements
gas inventories that furnish • Helps contractors
the foundation for policy and understand and meet
regulatory decisions agency requirements,
• Science-based GHG protecting contractor and
mitigation caps. customer
• A basis for reconciliation of • Ensures the quality of
determinations of GHG climate data records that
inventories from the top- furnish the foundation for
down and the bottom-up policy and regulatory
decisions
Economic Valuation of GHGs will
Drive Greater Accuracy Needs

22. 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”

23. GHG Point Source:
Pulverized Coal Power Plant
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
Flue Gas

24. Point Source Metrology
NIST Large Fire Facility: 1:100 scale stack model
Heat Release measure flow
Quantification for Many
properties & CO2
Materials & Structures
concentration in stack

25. Distributed GHG Emissions Sources and
Sinks (1 – 5 km Geographical Areas)
Optical Remote Sensing Technologies
cross sectional area Acs
x
z Hyperspectral Imaging
Determines Plume Cross-
section & Extent
y φ
Emission Source
GHG Mass
Flowrate
LIDAR
Doppler
Velocimeter
Lidar – Related Implementation Technologies
• Available for ~2 decades
• Significant technological advances by telecom technology
GHG Concentration industry in optical fibers and solid state lasers and amplifiers
DIAL: Differential Absorption LIDAR
• Platform for development of suitcase-sized systems

26. Heterodyne DIAL Measurement
Greenhouse Gas Area Source & Sink Mass Flux
CH4
• Dual beam heterodyne approach
CO2 • Common mode noise rejection
• Simultaneous sideband approach
N2O
(x1000)
H2O
1.646 λ / μm 1.590
Cavity Lock*
1.58-1.65 µm
On/Off - 10 GHz
P = 5 mJ (PPLN=20 mJ)
Δν=190 MHz (transform limited)
LiNbO3
3 µm

27. High Accuracy Spectroscopic Reference Data
O2 A Band (~765 nm) absorption spectrum
200 MHz
optical resonator pzt stabilized comb of
cw probe laser resonant frequencies
frequency -stabilized decay signal
reference laser
Frequency-stabilized cavity frequency
cavity stabilization servo ring-down spectrometer
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%
transition index

28. New Measurement Technologies
Photoacoustic Spectrometer
Self-calibrating instrument for measuring
absolute gas concentrations and aerosol
absorption coefficient.

29. NIST Radiometric Measurements
and Standards Capabilities
Supporting Satellite Calibrations
and
Performance Evaluation

30. NIST Primary Optical Watt Radiometer (POWR)
Optical Measurements are Traceable to the SI through the
Electrical Watt
• POWR provides optical
power measurement
capability to the LN2
0.01% (k = 2) level
• Primary Standard for
satellite radiometric Liquid
observing schemes He @
2K
Field or Satellite measurements required near the
level where standards are available are often a
significant challenge to realize.

31. Measurements Require Quality and Accuracy
High Resolution Infrared Radiation Sounder (HIRS) on the
Polar-Orbiting Operational Environmental Satellites (POES)
Vendor Vendor
NIST NIST
ΔT > 10 K ΔT up to 0.5 K
optical filter center wavelength Temperature sensitivity measurement
Resolves ~ 10 Kelvin Atmospheric Temperature
Measurement Discrepancy

32. Can GHG Observation Networks and Inverse
Modeling Be Applied to Verification
• Can GHG quantification and Source Inverse modeling combined with
ID Reach Spatial Resolutions weather data and atm. dispersion
of ~1 km? models regresses observed
concentrations to their source
• 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
Observing Obs.
– Inverse Modeling Resolution Network Station
• Boundary layer turbulence-induced limits –
velocity dispersive relationships AGAGE – NASA Supported,
• Accuracy of weather data Scripps-MIT Lead
• Optimize number of observing points NOAA – Tall Towers System
& CarbonTracker

33. 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

35. Thank You
&
Questions
Allan.eustis@nist.gov
http://www.nist.gov/cstl/ghg_clim
ate_overview.cfm