Mariani_Eureka_emiss..

Year-round Retrievals of O3,
CO, CH4, and N2O at Eureka
using Emission Spectroscopy
1Dept.
2Dept.
Zen Mariani1
K. Strong1, M. Palm2,
Physics, University of Toronto, Toronto, Canada
Physics, University of Bremen, Bremen, Germany
IRWG Annual Meeting
Abashiri-city, Hokkaido, Japan
June 10-14, 2013
Photo: Paul Loewen
Contents
What is the E-AERI?
n  Radiance Comparisons
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Cloudy vs. Clear-sky Measurements
SFIT2 Retrievals
Trace Gas Measurements Throughout
Polar Night
n  Comparisons, Seasonal and Diurnal
Variability
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What is the E-AERI?
Extended-Range Atmospheric Emitted Radiance Interferometer
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E-AERI Manufactured by ABB
Infrared Fourier Transform Spectrometer with 1 cm-1
resolution
Extended wavelength range covers 400-3000 cm-1 (3-25 µm)
Measurements of accurately calibrated downwelling infrared
thermal emission from the atmosphere
Spectra every 7 min, 24 hours
a day, 365 days a year
(precipitation permitting)
Image: ABB
à Measurements
independent of sunlight
Image: ABB Bomem
Data Sets
Measurement overlap
period:
October 2008 – May 2009
P-AERI
at 0PAL
March
2006
March
2007
P-AERI installed
March
2008
E-AERI
installed
at PEARL
E-AERI
at PEARL
Not Extendedrange
E-AERI
under repair
March
2009
March
2010
March
2011
P-AERI
removed
E-AERI detectors
damaged. Moved to
0PAL. 2 repair visits to
Eureka
E-AERI
under repair
E-AERI
at 0PAL
March
2012
E-AERI
at 0PAL
March
2013
Analogue-to-digital
converter damaged.
1 repair visit to
Eureka
P-AERI = Polar AERI (Von Walden, U Idaho, deployed by NOAA SEARCH program)
Radiance Comparisons
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Clear vs. Cloudy sky Radiance Comparisons
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Radiance increase: 790% (Southern Great Plains = ~300%)
Brightness temperature increase: 44%
Important for cloud filtering for trace gas retrievals
Comparisons to FLBLRTM-simulated radiances
Measured radiative forcing from ice crystal cloud using
E- and P-AERI (at two altitudes)
Mariani, Z., K. Strong, M. Wolff, P. Rowe, V. Waldlen, P. F. Fogal, T. Duck, G. Lesins, D. S. Turner, C.
Cox, E. Eloranta, J. R. Drummond, C. Roy, D. D. Turner, D. Hudak, and I. A. Lindenmaier: Infrared
measurements in the Arctic using two Atmospheric Emitted Radiance Interferometers, Atmos. Meas.
Tech., 5, 329-344, 2012
SFIT2 Retrievals
SFIT2 Total Column Retrievals
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SFIT2v393_MP (Mathias Palm)
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New emission add-on; incorporated into SFIT4
Adapted to run with emission spectra (works for all AERIs)
Automation code written (“Zephyr 3”)
Total column measurements of O3, CO, CH4, and N2O
during clear-sky conditions from PEARL (2008-2009) &
0PAL (2011-ongoing)
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First ground-based nighttime and polar night measurements of
these species at Eureka
High sensitivity to the troposphere
Comparisons with ground-based
instruments at Eureka
Seasonal and diurnal variability of trace
gases (i.e. CO)
Polar Night
Rodica Lindenmaier
Notes on the Retrievals
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Measurements are independent of sunlight
Cloudy spectra are filtered
(even thin clouds); measurements
are for clear-skies only
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750-1200 cm-1 ‘cloudy region’
Scaled retrievals (1-layer) on
38-layer altitude grid
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Profile retrievals had convergence
problems; likely that E-AERI spectral
resolution is too low
Retrieval Windows
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Details about retrieval miniwindows, interfering species,
and full error analysis are described in our (soon-to-be)
published paper:
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Mariani, Z., K. Strong, M. Palm, R. Lindenmaier, C. Adams, X. Zhao, V.
Savastiouk, C. T. McElroy, F. Goutail, J. R. Drummond. Year-round Retrievals of
Trace Gases in the Arctic using the Extended-range Atmospheric Emitted
Radiance Interferometer, Atmos. Meas. Tech., 2013 à accepted; Typesetting
5 km
5 km
Mariani et al., 2013
2008-2009
Measurements
from PEARL
Errors Included:
-Measurement (noise)
-Smoothing
-Temperature
-Linewidth (HITRAN)
-Interference
Different viewing geometries, etc.
2011 Measurements from 0PAL
Oct
Oct
Mariani et al., 2013
2008-2009
Measurements
from PEARL
Errors Included:
-Measurement (noise)
-Smoothing
-Temperature
-Linewidth (HITRAN)
-Interference
Different viewing geometries, etc.
2011 Measurements from 0PAL
Oct
Oct
Mariani et al., 2013
2008-2009
Measurements
from PEARL
Errors Included:
-Measurement (noise)
-Smoothing
-Temperature
-Linewidth (HITRAN)
-Interference
Different viewing geometries, etc.
2011 Measurements from 0PAL
Oct
Oct
Mariani et al., 2013
2008-2009
Measurements
from PEARL
Mariani et al., 2013
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Oct
Oct
Mean relative differences
are smaller than the total
uncertainties (Stot) of
E-AERI measurements
Similar agreement in
Yurganov et al. (2010)
between AERI CO and insitu CO measurements
2008-2009
Measurements
from PEARL
Mariani et al., 2013
Similar amplitude in the 24-hour
diurnal CO cycle in Yurganov et
al. (2010) AERI CO
measurements in Oklahoma
region
Oct
Oct
What I’m working on now…
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Retrievals of other trace gases (CO2, HCN, C2H2)
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Retrieving biomass burning products with high temporal
resolution
Compile downwelling radiances and brightness
temperatures at 10 μm and 20 μm (infrared cooling-tospace regimes)
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Classify clear-sky, thin-cloud, thick-cloud radiances and
brightness temperatures
Correlate with downwelling brightness temperature
Determine trends in radiances and brightness temperatures
Compare with Southern Great Plains climatology (Turner and
Gero, 2011, JGR)
Summary
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Clear vs. Cloudy Sky Radiance Comparisons
(Mariani et al., 2012, AMT)
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Validated radiances and compared to simulations
Large surface radiative forcing from clouds
6% increase in irradiance from thin, low-level ice cloud
Measurements from PEARL (2008-2009) and sea-level
from 0PAL (2011- ongoing)
Total columns of O3, CO, CH4, N2O during entire year
retrieved using SFIT2v393_MP (Mariani et al., 2013, AMT)
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Outlines modified SFIT2 emission algorithm
Describes E-AERI retrieval methodology and error analysis
First continuous ground-based Polar night measurements
Comparisons to other ground-based instruments at Eureka
Diurnal and seasonal cycle of trace gases
This can be extended à can retrieve other gases (CO2, etc.)
Acknowledgements
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CANDAC and PEARL are supported by:
n  ARIF, AIF/NSRIT, CFCAS, CFI, CSA, EC, GOC-IPY, NSERC, OIT,
ORF, INAC, and PCSP
Logistical and operational support at Eureka:
n  CANDAC operators
n  Team at the EC Weather Station
n  CANDAC/PEARL PI James R. Drummond
n  CANDAC data manager Yan Tsehtik
Canadian Arctic ACE Validation Campaigns supported by:
n  CSA, EC, NSERC, and NSTP
Thanks to Stephane Lantagne and Guillaume Gamache of ABB for
installing and repairing the E-AERI.
Special thanks to Pierre Fogal, Kaley Walker, Cyndi Whaley, Felicia
Kolonjari, Rodica Lindenmaier, Dan Weaver, and Simone Chaudhary
for assistance with ACE Validation Campaigns, codes, and providing
data