1. Generation and dissemination of climate/environmental relevant gas and aerosol standards
Hanspeter Andres

2. Agenda Introduction Climate relevant gas standards
current status and ideas for future research activities
Environmental relevant aerosol standards
Summary
METAS

3. Introduction Identified gas metrology needs
Physical and chemical properties of the atmosphere, i.e. its physical state, the chemical composition as well as the essential transport processes by means of optical remote sensing methodologies and local “in situ” sensing techniques, focusing on establishing traceability in measurements and the evaluation of uncertainties, for important atmospheric constituents and their precursors, reaction partners and isotopologues of the atmospheric Water-, Ozone-, Nitrogen-, Carbon- and Sulfur-cycles, and other reactive climate change relevant gaseous components.
METAS

4. Introduction Identified aerosol metrology needs
Traceable measurements are required for
size
number concentration
mass
surface area
for particles from a few nm up to several μm, especially at low concentrations
and for nanoparticles of different type and morphology.
The chemical composition of particulates remains a key issue for air quality.
METAS

5. Climate-relevant gas standards generation of SI-traceable halocarbons
Dynamic generation of reference gas mixtures with a coated magnetic suspension balance
Reference gas mixtures in the nmol/mol range collected in pressurized cylinders by cryotrapping
Scale comparison measurements using Medusa-GC-MS technology (Empa).
135 km I II
III
METAS

6. Climate-relevant gas standards halocarbon observation networks
NOAA/ESRL
Halocarbon Surface and Aircraft Sampling Network
AGAGE
Continuous Halocarbon in-situ
Sampling Network
METAS

7. Climate-relevant gas standards motivation extending work on halocarbons
Contribution of halocarbons to climate change is increasing
Current scale NOAA and AGAGE scales focus on precision not on SI-traceability
no WMO CCL for halocarbons
Legend: HFOs: 4th generation halocarbons
HFCs: 3rd generation halocarbons
HCFCs: 2nd generation halocarbons
CFCs: 1st generation halocarbons
Velders et al., Science (2012)
METAS

8. Climate-relevant gas standards HFCs – to be banned as well
Nature, 12. November 2015
“The world took a step in the right direction in the early hours of 6 November [2015]. Meeting in Dubai, 195 governments decided to pull the management of hydrofluorocarbons (HFCs) under the umbrella of the Montreal Protocol. [...] Unfortunately, some governments still seem to be hedging their bets. In particular, India, Saudi Arabia and Kuwait pushed to delay consideration of detailed amendments to the Montreal Protocol until next year. [...]
METAS

9. Environmental aerosol standards current aerosol calibration sources
Single-component
calibration aerosols
Generators
Aerosol properties
already
established
at METAS
Particle size: from a
few nm to a few μm
Oil droplets
Electrospray
Number concentration:
how many particles /cm3?
Salt particles
Chemical composition:
Inorganic, organic?
Does it contain trace metals?
Atomiser
Mass concentration:
μg of particulates pro m3
Combustion
particles
Particle morphology:
spherical, rod like, nanotubes?
miniCAST
METAS

10. Environmental aerosol standards aerosol characterisatioin
Multi-component
calibration aerosols
Generators
Aerosol properties
Particle size: from a
few nm to a few μm
Oil droplets
Electrospray
Number concentration:
how many particles /cm3?
Salt particles
Tunable
Chemical composition:
Inorganic, organic?
Does it contain trace metals?
Atomiser
Mass concentration:
μg of particulates pro m3
Combustion
particles
Particle morphology:
spherical, rod like, nanotubes?
miniCAST
METAS

11. Environmental aerosol standards composition of a representative ambient aerosol
Dust particles
Combustion particles
Organic particles
Salts
Bioaerosols Si Al Ca Fe Mg
K etc.
Elemental Carbon +
Organic Matter
Isoprene
Terpenes
Alcohols
Aldehydes
Ketones
etc
NO3-
NH4+
SO42-
Na+
Mg+
Cl-
etc.
Viruses
Bacteria
Fungi
Pollen
EC12.6%
Unknown 13.4%
Trace elements
Trace ele-
ments 13.8%
OM 26.5%
Humidity:
30%-80%
Mineral dust 8.2%
Sulfate (SO42-) 7.4%
METAS
Ammonium (NH4+) 5.2%
Nitrate (NO3-) 12.8%

12. Environmental aerosol standards ambient air generator
The mixing chamber will be equipped with:
Inlets for various primary aerosol species
Two-stage dilution air injection allowing for turbulent mixing
Humidity and temperature control for aerosol processing
Isokinetic sampling ports
Analysis:
Chromatography
Laser-induced incandescence
Particle counting
Particle sizing
Mixing
chamber
chemical to
optical
physical ✓ ✓
METAS

13. Environmental aerosol standards calibration of automatic PM-monitors
Particle mass concentration is the most important particle metric for air quality
Ambient threshold values for PM2.5 and PM10 have been established in Europe (EU Air Quality Directive 2008/50/EC) and worldwide
However, no reference aerosol exists for calibrating commercial PM- measuring instruments
Comparison to reference method with field measurements at least twice a year at 2 different sites (time-consuming/expensive procedures with high uncertainties)
Ambient air generators will allow calibrations in the lab
Automatic PM-instruments:
based on different
measurement techniques
different sampling inlet
TEOM (Tapered Element
Oscillating Microbalance)
Light scattering
Beta-absorption
METAS

14. Summary
Climate-relevant gas standards: continue and extend work on dynamic generation and crypotrapping of reactive and sub-ppt gas species; i.e. banned climate relevant gas components CFCs, HCFCs and HFCs under the 'Montreal Protocol‘ in collaboration with Empa
Environmental aerosol standard: develop an ambient aerosol source with tunable parameters such as particle size, number concentration, EC/OC ratio, PAHs and salt content for easy calibration of widely used PM monitors
Ideas for WPs and not entire JRPs, METAS/Empa are not entitled to coordinate
METAS

15. Thank you very much for your attention