AErosol%20Raman%20Ozone%20Lidar%20(AeROLidar)

1
AErosol Raman Ozone Lidar(AeROLidar)
OZONE PROFILES FOR THE ARCIONS CAMPAIGN APRIL/JUL
Y 2008

• Dr. Kevin Strawbridge
• Bernard Firanski
• Mike Harwood
• Michael Travis
• Kevin.strawbridge_at_ec.gc.ca
• Bernard.firanski_at_ec.gc.ca

ENVIRONMENT CANADA Centre for Atmospheric
Research Experiments
2
Location
                      
                                                                            

• Rural Ontario site

3
Instrument Introduction

• Dual wavelength single transmitter developed by
  Masahisa Nakazato (Met. Res. Inst., Japan)
• CO2 Raman scattering of 266 nm
• 287 (on) 299 nm (off) pair in Hartley band
• Initial configuration attempted double-pump
  Powerlites using a 2 m Raman cell
• Same pressure used by Japanese
• System is much more complicated than on paper!

4
Transmitters

• Continuum Powerlite 9030
• 266 nm at 100 mJ per pulse
• 30 Hz
• Continuum Inlite
• 532 nm at 340 mJ per pulse
• 30 Hz
• CO2 Raman cell
• 2 m long
• 400-700 kPa pressure

5
Receivers

• AERO Receiver
• 90 cm Cassegrain Telescope
• 287 299 Hamamatsu 7400 PMT pair
• Licel Transient Digitizer
• 1064, 607, 532 nm channels
• 355, 387, 407 nm channels
• Aerosol Lidar Receiver
• 45 cm Cassegrain Telescope

6
DIAL Algorithm Testing

• Simulated ozone profiles performed well w/o noise
• Tested concentration algorithm on a real profile
• Performed well even if missing aerosol
  characterization

7
Data Overview

• April Period
• Laser installed April 1
• First week used for alignment and synching of
  double-pump Powerlites
• Opted for single-pump
• Operational April 10
• First clear day April 15
• Collected until April 21
• Defective laser crystals hampered efforts
• Typical data limit of 6km

• July Period
• Significant cloud cover
• Used alternate Aerosol Lidar for 1064/532 nm
• Data collection from June 28-July 10
• Typical data limit of 8-10km
• Defective laser crystals
• Laser power instability

8
April Data
9
April Data

• Atmosphere was hazy the first week
• System not properly aligned
• 299 nm signal returns weak compared to 287 nm
  returns

10
Aerosol Plots
2008-04-15
2008-04-16
2008-04-17
2008-04-18
11
Aerosol Plots
2008-04-19
2008-04-20
2008-04-21
12
Ozone Aerosol Correlation?
13
July data
14
July data
15
Ozonesonde Comparison
16
Aerosol Plots
2008-06-28
2008-06-29
2008-07-02
2008-07-04
17
Aerosol Plots
2008-07-05
2008-07-06
2008-07-07
2008-07-10
18
Aerosol Correlation
19
Aerosol Correlation
20
Ozone Dynamics

• Apparent decrease in overall ozone content as
  evening progresses
• Structure evident near 5 km and near 2 km
• Ozone enhancement between 6-7 km around 1900 UTC?
• Does not match the aerosol structure chemistry
  dominating dynamics?

21
Current Data

• System alignment is far better
• Laser power stability improved
• Aerosol and DIAL systems now have common receiver
  

22
Summary

• Brand new instrument used for very first time
  during April campaign
• Significant improvement between April and July
• System performed well in matching overall ozone
  trends after correction factor applied
• Small-scale features do not match sonde, but
  sonde features varied even over a 4-hr span
• Concurrent aerosol scans show little correlation
• Dynamics are possible with the instrument

23
What Now?

• Instrument Development
• Continue investigating instrument performance
• Expand wavelengths
• Install a boundary layer telescope
• Investigate proper extinction and scatter
  exponents
• Include cloud screening

• Research
• Look for Boreal fire signatures
• Examine back-trajectories
• Examine MODIS aerosol swath data
• FLEXPART?
• AURAMS?

24
The End

• Thank You!

25
Signal Simulation and Calibration

• Calibration accomplished using model Lidar signal
  profile subject to actual ozone
• 3rd order polynomial correction factor generated
  from ratio of actual vs model signal profile
• Aerosols have minimal impact
• Noise is problematic at upper altitudes
• Calibration does well in correcting
  opti-mechanical effects w/o introducing features