caroline nowlan, xiong liu, cheng liu, gonzalo gonzalez abad, kelly chance harvard-smithsonian...
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Trace Gas Retrievals from the GeoTASO Aircraft Instrument during DISCOVER-AQ
Caroline Nowlan, Xiong Liu, Cheng Liu, Gonzalo Gonzalez Abad, Kelly ChanceHarvard-Smithsonian Center for Astrophysics, Cambridge, MA
James Leitch, Joshua Cole, Tom Delker, Bill Good, Frank Murcray, Lyle Ruppert, Dan Soo Ball Aerospace, Boulder, CO
Chris Loughner, Melanie Follette-Cook, Scott Janz, Matt Kowalewski, Ken PickeringNASA GSFC, Greenbelt, MD
GeoTASO
New test-bed instrument for the geostationary TEMPO (scheduled for launch 2018-2019) and GEO-CAPE (Decadal Survey) satellite instruments
First flights happened during DISCOVER-AQ on NASA Falcon Texas 2013 (6 flight days) Colorado 2014 (12 flight days)
GeoTASO Measurements
Measures with 2 detector arrays UV: 280 – 410 nm (O3, HCHO, SO2)
Visible: 416 – 690 nm (NO2, O3, aerosols) 2-D CCD array detector
One dimension across flight track and one in wavelength dimension
Resolution at surface: ~500x500 m2 (NO2, HCHO, O3)
~1x1 km2 (SO2) We retrieve slant columns using nearby zenith-sky
reference spectra, then convert to vertical columns with air mass factor from a radiative transfer code (VLIDORT, Spurr et al., 2006) using CMAQ at 4x4 km2 resolution
Current Status
Texas campaign: NO2 vertical columns available UV radiance calibration needs refinement
Colorado campaign: NO2 and SO2 slant columns available for 4 of 12 days
To come: Ozone profiles, NO2 vertical columns, HCHO, more flights to process
First Houston data should be up on DISCOVER-AQ data archive by the end of May.
Contact: [email protected]
DISCOVER-AQ Texas 2013
Houston:09/13, 09/14, 09/18, 09/24GeoCAPE ocean color
flight: 09/17
OMI underflight: 09/16
Transit out (GA power plants): 09/12
Transit back (NC power plants): 09/24
(NO2 data in red are currently available.)
DISCOVER-AQ Colorado 2014
Transit back (power plants, Kansas City, St. Louis): 08/13
Transit out (power plants): 07/25
Denver: 07/29, 07/31, 08/01, 08/02, 08/06, 08/08, 08/10, 08/11
West Colorado power plants: 08/09 Plateville Oil &
Gas:08/03
(NO2 data in red are currently available.)
NO2 over Houston (Cloud-free ground pixels)
VerticalColumn
13 Sept 201310:00-11:30AM
18 Sept 20139:00-11:45AM
24 Sept 201310:00-11:45AM
14 Sept 20132:00-5:00PM
GeoTASO NO2 vs PANDORA NO2 Houston Urban Flights
Cloud-free observations
Small bias, possible causes to be investigated:• Aerosols not
currently included in radiative transfer model for air mass factor calculation
• Effects from zenith sky observations or background offset removal using clean observations over water
GeoTASO NO2 vs EPA AQS NO2 Houston Urban Flights
Lamsal et al. (2008) method is often used to infer surface mixing ratio from satellite measurements: Scale satellite vertical column density (VCD)
using a model to get surface concentration (S).
GeoTASO NO2 (500x500 m2) vs GCAS NO2 on B-200 (250x500 m2)
Close flights on 13 September 2013 show very similar NO2
Both analyzed with GeoTASO algorithm
NO2 over Denver, Raster Scans2 August 2014
8:00 – 11:30 AM LOCAL TIME 2:00 – 4:00 PM LOCAL TIMESlantColumn
08/13/2014: Overpass of Labadie Power Station, Missouri
Photo by J.B. Forbes
GeoTASO measured coincident slant columns of NO2 and SO2 downwind from Missouri’s largest coal-burning power plant, on transit back to Virginia
Future Work
O3 profile work in preparation for TEMPO mission Formaldehyde retrieval optimization Aerosol sensitivities in air mass factor Process rest of Colorado data Improvements to UV calibration for Houston campaign Comparisons with GCAS, P-3B and satellites
Responsibility for GeoTASO transferring this year from Ball Aerospace to NASA Goddard (Scott Janz)