Sin ttulo de diapositiva

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AEROSOL ARCTIC CAMPAIGN AT ALOMARIN JUNE-JULY
2002
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V.E. Cachorro, C. Toledano, R. Vergaz, M.
Sorribas and A.M. de Frutos Grupo de Optica
Atmosférica Universidad de Valladolid Spain
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OVERVIEW
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OBJECTIVE
Determination and evolution of aerosol parameters

• AOD values (440, 670,80,1020)
• Angström parameters ?VIS-NIR ?pair
• -------------
• Microphysical Parameter effective radius,
  volume, mass,
• Radiative parameters wo, g, Phase Function

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INSTRUMENTATION
Brewer of ALOMAR
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Sun-photometer Cimel 318A (243) PHOTONS-AERONET
Zenith motor
Collimator
Sensor head
DCP antenna
Azimuth motor
Electronics
Solar panel
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METHODOLOGY
Determination of the aerosol optical depth
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Cimel Data
Standard AERONET data processing for
Aerosol Optical depth (AOD)
Pre calibration coefficients, Vo (?)
(intercalibration)
Rough measurements
Level 1.0
Cloud Screening AERONET
Measurements without clouds
Level 1.5
Post Calibration coefficients,
Level 2.0 (Quality Assured)
Final measurements (interpolation)
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AEROSOL CIMEL MEASUREMENTS
May 26th and July 24th 2002
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AEROSOL CIMEL MEASUREMENTS
May 26th and July 24th 2002
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AEROSOL CIMEL MEASUREMENTS Spectral analysis
alpha parameter
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AEROSOL CIMEL MEASUREMENTS
May 26th and July 24th 2002
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AEROSOL CIMEL MEASUREMENTS
May 26th and July 24th 2002, GENERAL STATISTIC
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AEROSOL CIMEL MEASUREMENTS
Medium turbidity values AOD0.14, alpha 2.04,
However, very thin cirrus cloud are present
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Weather Maps Back-trajectory Analysis
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AEROSOL CIMEL MEASUREMENTS
Low turbidity event AOD0.06 alpha1.4
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AEROSOL CIMEL MEASUREMENTS
High turbidity event AOD0.26 alpha1.9 Very
good days to study cirrus cloud with LIDAR
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EPP spectrograph (StellarNet) Calibration and
measurements Eight Channels

• Spectral Range (190-790) nm.
• In the field (300-600)
• Dinamic range 65000 counts.
• - Spectral Resolution ? 2 nm Sorribas M.,
  2001.
• - Error in wavelength ? 0.25 nm
• Detector CCD Hamamatsu de 64 1024 pixeles.
• - Entrance slit widh 25 ?m.
• -
• Stray Light lt 0.2 a 220 nm.
  

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EPP spectrograph (StellarNet) Calibration and
measurements Global Component Channel
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Langley Procedure in ALOMAR
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EPP spectrograph Calibration and
measurements Direct Component Channel
Comparison with the Langley method
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CONCLUSIONS

• A varying AOD evolution is observed
• The AOD values gives a median-low turbidity,
  about 0.13 at 440 nm, but higher than expected
• alpha parameter gt 1 indicate not clear marine
  type, with abundant fine particles, thus coastal
  marine type is mixed with polluted and
  continental aerosol types
• Size distribution particle and radiative
  parameter are in process. Measurement of Sky
  radiance needs to be added
• Comparative data of EPP with Bentham are in
  agreement
• Comparative AOD between EPP, Cimel, and Brewer
  are in process

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Thanks to ALOMAR team and specially to M.
Gausa Gracias