ARM Enhanced Shortwave Experiment (ARESE)
September 25 - November 1, 1995
Acoustic-optical spectrometer (AOS) & Photometer with multiple fields of view (PMFOV)
GENERAL INFORMATION
Principal Investigator: George S. Golitsyn
Institution: Institute of Atmospheric Physics, Russian Academy of Sciences.
Instrument: A. Acoustic-optical spectrometer (AOS). Provides measurements of direct and scattered solar radiation in wavelength range 0.415 -0.79 microns. Spectral resolution - 0.2 nm; minimal measurement time at one wavelength - 32 ms; FOV - 2 deg. B. Photometer with multiple fields of view (PMFOV). Measures direct and scattered in the cone with half-angles from 1 to 3.5 degrees solar radiation at six wavelengths from 0.5 to 1.2 microns. Instrument is mounted on the solar tracking system.
Brief statement of work including objectives, approach, and requisite atmospheric conditions:
The objectives of the work are to retrieve the microphysical parameters of aerosol in the atmospheric column and semi-transparent clouds. The measurement data from the acoustic-optical spectrometer enable to determine aerosol optical depth and phase function in aureole region. The PMFOV data are the "instrumental" optical depth of semi-transparent clouds which less than true because of input of scattered radiation. The data from both instruments are inverted to retrieve the parameters of aerosol (AOS) and cloud (PMFOV) size distributions. Requisite atmospheric conditions: cloudless sky, or semi-transparent clouds with optical depth up to 4 - 5. Max. wind velocity 10 m/s (limited by solar tracking system).
Is the information to be gathered during the IOP for the support of an ARM Instrument Development Program (IDP) project? No
DATA CONTRIBUTIONS TO ARM
Data to be released to the ARM Science Team and the estimated availability date (months after IOP) for each of these data.
I. Aerosol and semi-transparent cloud optical depth.
II. Estimations of cloud particle's effective radii. III. Columnar aerosol volume concentration.Availability date: six month after IOP.
Units: I-dimensionless; II -microns; III- cm^3/m^2
Accuracy (proximity to true value) I- 0.05; II- 50%; III- 15 -20%
Precision (repeatability, reciprocal of sample variance)
Range of acceptable values: I - 0 - 4; II - 2 - 20 mcm;
Temporal resolution (temporal representativeness of observation) depending upon the atmospheric conditions (minimum -2 min)
Temporal reporting interval (time interval between successive observations)
Vertical resolution
Vertical range (minimum and maximum)
Vertical coordinate (meters above mean sea level, millibars, etc.)
Horizontal resolution
Horizontal range (minimum and maximum)
Horizontal coordinate (UTM, lat/long, etc.)
Angular resolution
Angular spacing
Spectral resolution 0.2 nm (AOS)
Spectral range 415 - 790 nm (AOS); 0.5 - 1.2 mcm (PMFOV).
Data format: ASCII.
