Atmospheric CO 2 and CH 4 Measurements

Transcription

1 Atmospheric CO 2 and CH 4 Measurements Ray Nassar ray.nassar@ec.gc.ca Climate Research Division, Environment Canada NSERC-CREATE Summer School on Arctic Science, 2013

2 Beginning of atmospheric CO 2 measurements : Charles David Keeling began monitoring atmospheric CO 2 at Mauna Loa Hawaii and the South Pole

3 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)

4 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

5 Flask and continuous measurements 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 1s precision ~ 0.1 ppm, accuracy ~0.2 ppm relative to WMO standards

6 Expansion of Surface Networks

7 Aircraft measurements CO 2 CO 2, CH 4 CONTRAIL (Comprehensive Observation Network for Trace Gases by Airliner) HIPPO (Hiaper Pole-to-Pole Observations) CONTRAIL and CARIBIC have take-off / landing but mostly cruising altitude of ~10.5 km CO 2, CH 4 CARIBIC (Civil Aircraft for the Regular Investigation of the Atmosphere Based on an Instrument Container) HIPPO 5 campaigns (~ 1 month each) during , 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, CO 2 -sondes, AirCore

8 Point measurements - Representativeness zoom Major mismatch in scales between measurement and model they are not representative of one another Mauna Loa peak 4.17 km, measurement site 3.4 km 2 x2.5 gridbox = 222 x 261 km 2 (at 20 N) Nassar et al. (2010), Geoscientific Model Development, 3,

9 Desirable CO 2 or CH 4 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 CO 2 ), requires good SNR and spectral resolution Ancillary: Measurements of cloud/aerosol, O 2 A-band, other species No single satellite can meet all of these requirements

10 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 To be released in late 2013 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)

11 NIR solar reflectance TIR emission First Generation of GHG Satellite Observations March-April-May multi-year average HIRS TOVS AIRS IASI TES Chédin et al. (2003) Chahine et al. (2008) Crevoisier et al. (2009) Kulawik et al. (2010) SCIAMACHY Buchwitz et al. (2007) All of these (except HIRS) also provide CH 4 Crisp et al. (2004, ASR) Limb TIR Solar Occultation Profiles ACE-FTS (Foucher et al. 2011)

12 Greenhouse Gases Observing Satellite (GOSAT) Japan (JAXA / NIES / MOE) launched in 2009 Glint ocean observation Thermal And Near-infrared Sensor for carbon Observation (TANSO) TANSO-FTS is main instrument with interferometer from ABB (Canada) Band 1) μm Band 2) μm Band 3) μm Band 4) μm (TIR) TANSO-CAI for cloud aerosol imaging

13 Greenhouse Gases Observing Satellite (GOSAT) Mean XCO XCO 2 [ CO2 ] [ O ] 2 v1.2 averaged at 2 x2.5 High latitude retrievals are limited by Solar Zenith Angle, Surface Albedo Cloud OD < 0.20 Only ~7% of GOSAT CO 2 and CH 4 observations pass cloud filter (Yoshida et al. 2011, Retrieval algorithm for CO 2 and CH 4 column abundances from shortwavelength infrared spectral observations by the Greenhouse gases observing satellite, AMT, 4, , 2011) GOSAT d = 10.5 km Miller et al. (2007, JGR) based on Breon et al. (2005, GRL)

14 Total Carbon Column Observing Network (TCCON) October 2011 but new ones and more to come Record direct solar spectra in the NIR (resolution 0.02 cm -1 ) to retrieve column-averaged mole fractions: XCO 2, XCH 4, etc. Wunch et al. (2011), The Total Carbon Column Observing Network, Phil. Trans. R. Soc. A, 369, TCCON uses only Bruker 125HR Fourier Transform Spectrometers. Other FTS measurements exist such as in the Canadian FTIR Observing Network (CAFTON)

15 Atmospheric Carbon Observations from Space (ACOS) Retrievals from GOSAT

16 GOSAT XCO 2 Bias Correction Column-averaged dry air CO 2 mole fraction XCO 2 = *[CO 2 ] / [O 2 ] Depends on surface pressure derived using the O 2 A-band Butz et al. (2011, GRL) Toward Accurate CO 2 and CH 4 Observations from GOSAT Retrieval precision continues to improve

17 Orbiting Carbon Observatory 2 OCO 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 km 2 ) XCO 2 using O 2 A-band, front of the A-Train Million Observations per month (GOSAT ~14,000)

18 Key Future GHG Missions with Surface Sensitivity OCO-2 (NASA, 2014) - XCO 2 goal of 1.0 ppm precision, O 2 A-band, 1.29 x 2.26 km 2 footprint, A-train, NIR nadir and glint at high latitudes TanSat (China, 2015) - Same CO 2 and O 2 bands as OCO-2 but also a Cloud and Aerosol Imager (CAI) MERLIN (DLR-CNES, 2016) - CH 4 Lidar (night and day measurements) OCO-3 (NASA, 2017) - OCO-2 spare parts on International Space Station GOSAT-2 (Japan, 2018) - CO 2, CH 4, and O 2 A-band with smaller footprint, expanded glint range for ocean observations (perhaps also CO) MicroCarb (CNES, 2019) - XCO 2 from satellite ~30-50% the size and cost of OCO-2 with similar sensitivity, step toward low-cost constellation PCW-PHEOS-FTS (CSA, 2020) - CO 2, CH 4, O 2 A-band and other gases, under consideration for mission with focus on northern high latitudes CarbonSat (ESA, 2020) - CO 2, CH 4 and O 2 A-band, 2 x 2 km 2 pixels and broad swath, high precision, 1 of 2 competing Earth Explorer 8 missions ASCENDS (NASA, 2021) - CO 2 Lidar (night and day measurements) Apologies for the Acronyms!

19 Comparison of Footprints and Swaths 1.29 x 2.26 km km 0.1 diameter 0.1 Figure provided by Heinrich Bovensmann (University of Bremen)

20 CarbonSat Point Sources AMT, 2010 CO 2, CH 4, O 2 A-band

21 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 CH 4 DIAL, pressurized Nd:YAG laser Active Sensing of CO 2 over Nights, Days and Seasons (ASCENDS) CO 2 and O 2 Lidars, currently 3 competing instrument designs from different NASA centers Launch is no earlier than 2023

22 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

23 ACE CH 4 and CO 2 ACE-FTS uses CO 2 spectral lines to retrieve temperature and altitude (related to pressure) based on assumed values of CO 2 CH 4 profiles can be retrieved using T,P from CO 2 but CO 2 retrieval requires altitude (pressure) derivation in some other way Foucher et al. (2011) use N 2 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 CO 2 (ppm) May 2007 Foucher, Chedin, Armante, Boone, Crevoisier, Bernath (2011), CO 2 atmospheric vertical profiles retrieved from space observation using ACE-FTS solar occultation instrument, Atmos. Chem. Phys., 9,

24 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 CH 4 profiles: upper troposphere and above Pointing information from solar imagers instead of spectra CO 2 profiles: upper troposphere and above without reliance on N 2 continuum Unique for the high vertical resolution capability PI: K.A. Walker (University of Toronto)

25 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 v averaged at 0.9 x 0.9 )

26 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

27 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) Apogee hour orbit with apogees slightly higher than GEO Three Apogee Orbit (16-hr) Perigee Trishchenko et al. (2011), J. Atmos. Ocean. Tech.

28 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

29 PHEOS-WCA Instrument Configurations Fourier Transform Spectrometer (FTS) UV-Visible Spectrometer (UVS) CSA Allocations Size: 30 x 30 x 30 cm 3 ( cm 3 ) Optimal Configuration All Bands Configuration Compliant Configuration Mass: 50 kg Power: 100 W FTS (aperture 15 cm) with UVS, 85 kg ~ * cm 3 FTS (aperture 10 cm) with UVS, 45 kg ~35 128* cm 3 FTS (aperture 10 cm) No O 2 A band or SWIR CO 2 O 2 A band and SWIR CO 2 No UVS, 37 kg ~25 184* cm 3 *volumes shown with 20% contingency

30 PHEOS-FTS observation locations 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 km 2 pixels. Checkerboard pattern of data-thinning to meet downlink requirement, and observations every other repeat cycle to accommodate other observing priorities Nassar et al, Satellite observations of CO 2 from a Highly Elliptical Orbit (HEO) for studies of the northern high latitude carbon cycle, submitted to JGR