Spectroscopic Study of Atmospheric Trace Gases Using PARIS-IR from

Waterloo Atmospheric Observatory in 2005 and 2006

Dejian Fu, Kaley Walker, Keeyoon Sung, Chris Boone, Peter Bernath

Waterloo Atmospheric Observatory (WAO)

Goals of WAOTo observe the concentrations of atmospheric trace gases simultaneouslyTo conduct measurements over large time scales for observing trendsTo assist in validating Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS)

Location of WAOThe rooftop of the Center for Environmental and Information Technology,

University of Waterloo (43.47º, 80.54ºW, 319 m above sea level) Main instruments at WAO

1. Portable Atmospheric Research Interferometric Spectrometer, for the Infrared (PARIS-IR)

2. ABB Bomem DA8 (MOPD = 50 cm, Near IR-Vis-UV) From PARIS-IR spectra, we have been able to retrieve 13 species: O3, HCl, CH4, N2O, H2O, HNO3, NO, NO2, CCl3F, CCl2F2, HF, CO, OCS

Portable Instrument - PARIS-IR

MANTRA 2004 balloon

campaign

mini-MANTRA campaign

WAO

ACE Arctic Validation Campaigns

Ground-based Observations of PARIS-IR

azimuth gimbal

sun sensor

pointing mirror

solar beam

Max. Res. : 0.02 cm-1

Meas. Reg.: 750 – 4400 cm-1 Max. Scan Speed: 2.5 cm/sDetectors : InSb and HgCdTe

elevation gimbal

GPS receiver

control computer

pendulum arm

ZnSe beam splitter

O3

N2O

CO2

CH4

HFHCl

CO2 H2O

HNO3

O3

NO

Spectra recorded on July 30th, 2005 at WAO

Retrievals: Process of Going from Spectra to Trace Gas Concentration

Computed Spectra

Observed Spectra

Optimal Estimation

a priori VMR profiles from TAO

p & T profile from NCEP and 1976 USA standard atmosphere

spectral line parameters (HITRAN2004)

air mass (RAYTRACE)

altitude grid (29 layers)

Discrepancy within a specified

convergence criterion

Output retrieval result

Volume Mixing Ratio (VMR)National Centers for Environment Prediction (NCEP)Toronto Atmospheric Observatory (TAO)

Adjust VMR Profile

yes

No

A retrieval code named SFIT2 (C. Rinsland et al). used for trace gas retrievals. It contains a line-by-line calculation program for the forward model and uses the optimal estimation method for the inverse algorithm (C. Rodgers et al. ).

A Sample for CH4 Retrieval Using Spectrum Recorded on July 30, 2005

2859.3 2859.4 2859.5 2859.6 2859.7 2859.8 2859.9 2860 2860.1-4-2024

Res

idu

als(

%)

2859.3 2859.4 2859.5 2859.6 2859.7 2859.8 2859.9 2860 2860.10.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

(cm-1)

Am

plit

ud

e (a

rbit

ary

un

it)

Meas Spec.Calc. Spec.

Column Densities Retrieved from Spectra on July 30, 2005

Daily Mean Column3.58 X 1019 molecules/cm2

1 Standard Deviation3.51 X 1017 molecules/cm2

Error bars indicatetotal errors (systematic and random errors).

Each data point is obtained from 20 spectra recorded in 6.6 minutes.

Characterization of CH4 Retrieval

Degree of freedom =2.07

-0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.80

5

10

15

20

25

30

35

Averaging kernel values

Alt

itu

de

(km

)

12.5 - 100 km

0.31 - 12.5 km

total Column

CH4MW2835

Characterization of O3 Retrieval

-0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.80

5

10

15

20

25

30

35

40

45

50

Averaging kernel values

Alt

itu

de

(km

)

12.5 - 100 km

0.31 - 12.5 km

total Column

O3MW2775

Degree of freedom =1.02

Error Estimation

CH4 O3

MW2835 MW27752.5 2.7< 1 < 1< 1 < 12.8 3.02.0 5.01.3 4.36.2 8.96.6 11.17.2 11.5Total Error

Systematic Errors

Spectroscopic ParameterEmpirical Apodization Function

A prioriSubtotal

Error SourcesErrors (in %)

Random Errors

Retrieval ErrorSolar Zenith Angle

TemperatureSubtotal

Total Ozone from MSC Brewer UV Spectrometer at Toronto and PARIS-IR at WAO

05/01/01 05/04/01 05/07/01 05/10/01 06/01/01 06/04/01 06/07/01250

300

350

400

450

500

Date (YY/MM/DD)

To

tal O

zon

e (i

n D

U)

MSC Daily Total Ozone MSC Monthly Mean OzonePARIS-IR Daily Ozone

Map of ACE Occultation Location within 1000 km from June 2005 to May 2006

12 coincident ACE observations

Partial Column Densities of O3 from ACE and PARIS-IR (17.5 km to 100 km)

26/06/05 03/07/05 10/07/05 17/07/05 24/07/05 31/07/05200

210

220

230

240

250

260

270

280

290

300

Date

To

tal C

olu

mn

(in

DU

)

ACE-FTSACE-MAESTRO (UV)ACE-MAESTRO (Vis)PARIS-IR

Agree to within 5%

Partial Column Densities of HCl from ACE and PARIS-IR (17.5 km to 100 km)

26/06/05 03/07/05 10/07/05 17/07/05 24/07/05 31/07/052.4

2.5

2.6

2.7

2.8

2.9

3

3.1

3.2

3.3

3.4x 10

15

Date

To

tal C

olu

mn

(in

#/c

m2)

ACE-FTSPARIS-IR

Agree to within 5%

Partial Column Densities of HNO3 from ACE and PARIS-IR (17.5 km to 100 km)

26/06/05 03/07/05 10/07/05 17/07/05 24/07/05 31/07/056.5

7.0

7.5

8.0

8.5

9.0

Date

To

tal C

olu

mn

(in

#/c

m2)

ACE-FTSPARIS-IR

Differences between 2% and 12%

Summary and Future work

Completed 50 days observations were performed using PARIS–IR at WAO from

June 2005 to May 2006. 12 ACE occultations were recorded within 1000 km of WAO.

Column densities of 7 trace gases were retrieved using SFIT2 program.

Good agreement of the results are achieved between PARIS–IR, Brewer, and ACE-FTS, ACE-MAESTRO measurements.

To do Observations and further analysis are on going at WAO. Correlations between species will be investigated. Simultaneous atmospheric observations using PARIS-IR and DA8 at

WAO are in our plan.

Acknowledgements

World Ozone and Ultraviolet Radiation Data Center

Meteorological Service of Canada

Natural Sciences and Engineering Research Council, Canada

Canadian Space Agency