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 WAO  To observe the concentrations of atmospheric trace gases simultaneously  To conduct measurements over large time scales for observing trends  To assist in validating Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) Location of WAO The 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: O 3, HCl, CH 4, N 2 O, H 2 O, HNO 3, NO, NO 2, CCl 3 F, CCl 2 F 2, 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/s Detectors : InSb and HgCdTe elevation gimbal GPS receiver control computer pendulum arm ZnSe beam splitter

O3O3 N2ON2O CO 2 CH 4 HF HCl CO 2 H2OH2O HNO3 O3O3 NO Spectra recorded on July 30 th, 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 CH 4 Retrieval Using Spectrum Recorded on July 30, 2005

Column Densities Retrieved from Spectra on July 30, 2005 Daily Mean Column 3.58 X molecules/cm 2 1  Standard Deviation 3.51 X molecules/cm 2 Error bars indicate total errors (systematic and random errors). Each data point is obtained from 20 spectra recorded in 6.6 minutes.

Characterization of CH 4 Retrieval Degree of freedom =2.07

Characterization of O 3 Retrieval Degree of freedom =1.02

Error Estimation

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

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

Partial Column Densities of O 3 from ACE and PARIS-IR (17.5 km to 100 km) Agree to within 5%

Partial Column Densities of HCl from ACE and PARIS-IR (17.5 km to 100 km) Agree to within 5%

Partial Column Densities of HNO 3 from ACE and PARIS-IR (17.5 km to 100 km) 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 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