Atmospheric CO2 and CH Measurements · 2013-07-17 · Atmospheric CO 2 and CH 4 Measurements Ray...
Transcript of Atmospheric CO2 and CH Measurements · 2013-07-17 · Atmospheric CO 2 and CH 4 Measurements Ray...
Atmospheric CO2 and CH4 Measurements
Ray Nassar [email protected]
Climate Research Division, Environment Canada
NSERC-CREATE Summer School on Arctic Science, 2013
Beginning of atmospheric CO2 measurements
1957-58: Charles David Keeling began monitoring atmospheric CO2 at
Mauna Loa Hawaii and the South Pole
Global Greenhouse Gas Measurements
Red denotes “active”: data from the station has been updated in the last 365 days
Archived at the World Data Centre for Greenhouse Gases (WDCGG)
WMO Global Atmospheric Watch (GAW)
Canadian Greenhouse Gas Measurement Program
(80°N, 86°W) Northernmost Site in the World
Flasks since 1975 and continuous since 1978
Intercomparison site (EC, NOAA, CSIRO, …)
since
2012
since 2012
since
2010
Flask and continuous measurements
• 1s precision ~ 0.1 ppm, accuracy ~0.2 ppm relative to WMO standards
• Whole air flasks collected and
analyzed in a central lab, commonly
by Gas Chromatography (GC) with
various different detection systems
(Mass Spec, FID etc.)
• Continuous measurements can be
done in the field using Non-dispersive
Infrared (NDIR) or Cavity Ring Down
Spectroscopy (CRDS) aka ‘Picarro’
NDIR
CRDS
Downsview
Expansion of Surface Networks
http://www.earthnetworks.com/
Aircraft measurements
• CONTRAIL and CARIBIC have take-off / landing
but mostly cruising altitude of ~10.5 km
• HIPPO 5 campaigns (~ 1 month each) during
2009-2011, repeated ascents/descents
• Also limited aircraft vertical profiles (Park Falls,
Southern Great Plains, Rarotonga Cook Islands, …)
and many small campaigns over the years, as well
as balloon measurements, CO2-sondes, “AirCore”
CO2
CO2, CH4 …
CO2, CH4 …
CONTRAIL (Comprehensive Observation
Network for Trace Gases by Airliner)
CARIBIC (Civil Aircraft for the Regular
Investigation of the Atmosphere Based
on an Instrument Container)
HIPPO (Hiaper Pole-to-Pole Observations)
Point measurements - Representativeness
2°x2.5° gridbox = 222 x 261 km2 (at 20°N)
Nassar et al. (2010), Geoscientific
Model Development, 3, 689-716.
Mauna Loa
peak 4.17 km,
measurement
site 3.4 km
383.75 384.50
zoom
Major mismatch in scales between
measurement and model …
they are not representative of one
another
Desirable CO2 or CH4 Measurement Characteristics for Source/Sink Estimation
• Horizontal Coverage: Observations over land, water and ice, all latitudes
• Footprint or Pixel: Small is good for horizontal resolution and more cloud-free observations, but must be large enough for sufficient signal
• Vertical Sensitivity: Surface sensitivity and vertical information
• Temporal Sampling: Sampling of seasonal and diurnal cycles
• Precision: High precision is very important (especially for CO2), requires good SNR and spectral resolution
• Ancillary: Measurements of cloud/aerosol, O2 A-band, other species
No single satellite can meet all of these requirements
Committee on Earth Observation Satellites (CEOS) Carbon Task Force
The CEOS Strategy for Carbon Observations from Space
• Introduction
• Land Domain
• Ocean Domain
• Atmosphere Domain
• Integration and the Way Forward
Berrien Moore (University of Oklahoma)
John Burrows (University of Bremen)
David Crisp (NASA-JPL)
Martin Heimann (Max Planck Inst. Jena)
Michio Kawamiya (JAMSTEC)
Ray Nassar (Environment Canada)
Peter Rayner (LSCE) To be released in late 2013
First Generation of GHG Satellite Observations
AIRS
SCIAMACHY
IASI TES
March-April-May multi-year average
Crevoisier et al. (2009) Chahine et al. (2008)
Buchwitz et al. (2007)
Kulawik et al. (2010)
HIRS TOVS
Chédin et al. (2003) TIR
em
issio
n
NIR
so
lar
refl
ecta
nce
Limb TIR Solar Occultation Profiles
ACE-FTS (Foucher et al. 2011)
All of these
(except HIRS)
also provide
CH4
Crisp et al.
(2004, ASR)
Greenhouse Gases Observing Satellite (GOSAT)
Thermal And Near-infrared Sensor for carbon Observation (TANSO)
TANSO-FTS is main instrument with interferometer from ABB (Canada)
Band 1) 0.758-0.775 μm Band 2) 1.56-1.72 μm
Band 3) 1.92-2.08 μm Band 4) 5.56-14.3 μm (TIR)
TANSO-CAI for cloud aerosol imaging
Glint ocean observation
Japan (JAXA / NIES / MOE) launched in 2009
Greenhouse Gases Observing Satellite (GOSAT)
v1.2 averaged at 2°x2.5°
350 400
Mean XCO2 2009-09
Cloud OD < 0.20
Miller et al. (2007, JGR)
based on Breon et al. (2005, GRL)
GOSAT
d = 10.5 km Only ~7% of GOSAT CO2 and CH4
observations pass cloud filter (Yoshida et al. 2011, Retrieval algorithm for CO2
and CH4 column abundances from short-
wavelength infrared spectral observations by the
Greenhouse gases observing satellite, AMT, 4,
717–734, 2011)
][
][2095.0
2
22
O
COXCO
High latitude retrievals are limited by
Solar Zenith Angle, Surface Albedo
Total Carbon Column Observing Network (TCCON)
Record direct solar spectra in the NIR (resolution 0.02 cm-1) to
retrieve column-averaged mole fractions: XCO2, XCH4, etc. Wunch et al. (2011), The Total Carbon Column Observing Network, Phil. Trans. R.
Soc. A, 369, 2087-2112
October 2011 but new ones and more to come
TCCON uses only Bruker 125HR Fourier Transform Spectrometers. Other FTS
measurements exist such as in the Canadian FTIR Observing Network (CAFTON)
Atmospheric Carbon Observations from Space
(ACOS) Retrievals from GOSAT
GOSAT XCO2 Bias Correction
Butz et al. (2011, GRL) “Toward Accurate
CO2 and CH4 Observations from GOSAT”
“Column-averaged dry air
CO2 mole fraction”
XCO2 = 0.2095*[CO2] / [O2]
Depends on surface
pressure derived using the
O2 A-band
Retrieval precision
continues to improve
Orbiting Carbon Observatory 2
OCO launch
photo by Matt Rogers,
Colorado State University
• OCO-2 is a rebuild of OCO which failed to reach orbit due to a launch mishap
• 3 grating spectrometers (narrow 2.0, 1.6, 0.76 mm bands)
• High precision (~1 ppm), nadir and glint, small footprint (1.25 x 2.26 km2) XCO2 using O2 A-band, front of the A-Train
• Million Observations per month (GOSAT ~14,000)
OCO
Key Future GHG Missions with Surface Sensitivity
• OCO-2 (NASA, 2014) - XCO2 goal of 1.0 ppm precision, O2 A-band, 1.29 x
2.26 km2 footprint, A-train, NIR nadir and glint at high latitudes
• TanSat (China, 2015) - Same CO2 and O2 bands as OCO-2 but also a
Cloud and Aerosol Imager (CAI)
• MERLIN (DLR-CNES, 2016) - CH4 Lidar (night and day measurements)
• OCO-3 (NASA, 2017) - OCO-2 spare parts on International Space Station
• GOSAT-2 (Japan, 2018) - CO2, CH4, and O2 A-band with smaller footprint,
expanded glint range for ocean observations (perhaps also CO)
• MicroCarb (CNES, 2019) - XCO2 from satellite ~30-50% the size and cost
of OCO-2 with similar sensitivity, step toward low-cost constellation
• PCW-PHEOS-FTS (CSA, 2020) - CO2, CH4, O2 A-band and other gases,
under consideration for mission with focus on northern high latitudes
• CarbonSat (ESA, 2020) - CO2, CH4 and O2 A-band, 2 x 2 km2 pixels and
broad swath, high precision, 1 of 2 competing Earth Explorer 8 missions
• ASCENDS (NASA, 2021) - CO2 Lidar (night and day measurements)
Apologies for the Acronyms!
Comparison of Footprints and Swaths
1.29 x 2.26 km2 10.5 km
diameter
Figure provided by Heinrich Bovensmann
(University of Bremen)
0.1
0.1
CarbonSat – Point Sources
CO2, CH4, O2 A-band
AMT, 2010
Space-based Lidars
• Lidars are ‘active’, do not need solar reflectance, measure during the night / polar night, and potentially better SNR over snow/ice, but only measure along satellite ground-track
• Methane Remote Lidar Mission (MERLIN)
~100 kg platform to launch around 2016
CH4 DIAL, pressurized Nd:YAG laser
• Active Sensing of CO2 over Nights, Days and Seasons (ASCENDS)
CO2 and O2 Lidars, currently 3 competing instrument designs from different NASA centers
Launch is no earlier than 2023
GHGSat
• Demonstration nanosatellite to launch
in 2015 from a Montreal company
• Commercial satellite (not research) to
measure emissions from Oil &Gas
industry, Power Generation, Landfills,
Mining and other
• Will utilize a Fabry-Perot spectrometer
which evolved from the Miniature
Earth Observing Satellite (MEOS)
concept once proposed to CSA by
Prof. Jim Sloan
ACE CH4 and CO2
• ACE-FTS uses CO2 spectral lines to retrieve temperature and altitude (related to pressure) based on assumed values of CO2
• CH4 profiles can be retrieved using T,P from CO2 but CO2 retrieval requires altitude (pressure) derivation in some other way
• Foucher et al. (2011) use N2 continuum
• Similar work being carried out by Chris Sioris
• 30 profiles per day (maximum) but continuum retrieval is very sensitive to cloud and only ~7% pass cloud filtering
ACE CO2 (ppm) May 2007
Foucher, Chedin, Armante, Boone, Crevoisier, Bernath
(2011), CO2 atmospheric vertical profiles retrieved from
space observation using ACE-FTS solar occultation
instrument, Atmos. Chem. Phys., 9, 2873-2890.
Chemical and Aerosol Sounding Satellite
• CASS satellite have FTS along with solar
imagers
• Proven FTS technology from ACE applied to a
‘climate’ focus, with increased low latitude
coverage
• CH4 profiles: upper troposphere and above
• Pointing information from solar imagers instead
of spectra
• CO2 profiles: upper troposphere and above
without reliance on N2 continuum
• Unique for the high vertical resolution
capability
PI: K.A. Walker (University of Toronto)
Satellite Orbits and Coverage
• Low Earth Orbit (LEO)
• Near-polar plane
• If sun-synchronous,
Earth’s rotation gives
global sampling but only
at a fixed overpass time
• Geostationary Orbit (GEO)
• Near-equatorial plane ~35,800 km altitude
• Synchronized with Earth rotation to give
continuous sampling over selected area
(<60°N/S)
• TEMPO / GEO-CAPE, Sentinel-4, GEMS
for Tropospheric Chemistry
GOSAT (NIES v2.00 2009-08 averaged at 0.9° x 0.9°)
Satellite Orbits and Coverage
• Low Earth Orbit (LEO)
• Near-polar plane
• If sun-synchronous,
Earth’s rotation gives
global sampling but only
at a fixed overpass time
• Geostationary Orbit (GEO)
• Near-equatorial plane ~35,800 km altitude
• Synchronized with Earth rotation to give
continuous sampling over selected area
(<60°N/S)
• TEMPO / GEO-CAPE, Sentinel-4, GEMS
for Tropospheric Chemistry
Highly Elliptical Orbit (HEO)
• WMO Vision for the Global Observing System (GOS) in 2025
• Conservation of angular momentum requires faster motion when
close to Earth (perigee), slower motion when far from Earth (apogee)
• 12-24 hour orbit with apogees
slightly higher than GEO
Apogee
Perigee
Three Apogee Orbit (16-hr)
Trishchenko et al. (2011), J. Atmos. Ocean. Tech.
Polar Communications and Weather (PCW)
• Canadian Space Agency led mission with 2 satellites in Highly Elliptical Orbit (HEO) under consideration for launch ~ 2020
• Weather - Environment Canada
– Operational meteorological imaging instruments for northern latitudes
• Communications - Department of National Defence
– Increase northern communications capability
• CSA is also considering additional science instruments
• Weather, Climate and Air quality (WCA) mission concept (PI: Jack McConnell, York U) is an atmospheric research option that completed Phase A last year, under the Polar Highly Elliptical Orbit Science (PHEOS) program
PHEOS-WCA Instrument Configurations
• Fourier Transform Spectrometer (FTS)
• UV-Visible Spectrometer (UVS)
CSA
Allocations
Size:
30 x 30 x 30 cm3
(27 000 cm3)
Mass: 50 kg
Power: 100 W
All Bands Configuration
Optimal Configuration
Compliant Configuration
FTS (aperture 15 cm)
with UVS, 85 kg
~103 800* cm3 FTS (aperture 10 cm)
with UVS, 45 kg
~35 128* cm3 FTS (aperture 10 cm)
No O2 A band or SWIR CO2
No UVS, 37 kg
~25 184* cm3
*volumes shown with 20% contingency
O2 A band and SWIR CO2
PHEOS-FTS observation locations
Checkerboard pattern of data-thinning to meet downlink requirement, and
observations every other repeat cycle to accommodate other observing priorities
Three-APogee (TAP) orbit
2 satellites, 8h apart in co-planar 16h orbit
Apogee ~43,500 km, Perigee ~8100 km
3 Apogees/day (8:00 and 16:00 local time)
observing ±4 h from apogee giving up to 16 h
of data per 48 h per region/apogee. Each
region: 48 scans for 100 sec each, consisting
of 56x56 array of 10x10 km2 pixels.
Nassar et al, Satellite observations of CO2 from a Highly Elliptical Orbit (HEO) for
studies of the northern high latitude carbon cycle, submitted to JGR