Multiple-scattering effect on ozone retrieval from space-based differential absorption lidar measurements.

Area of Science:

• Atmospheric Science
• Remote Sensing
• Spectroscopy

Background:

• Accurate global ozone measurements are crucial for understanding atmospheric chemistry and climate.
• Spaceborne differential absorption lidar (DIAL) systems offer a promising approach for global ozone monitoring.
• The influence of multiple scattering on lidar signals, particularly for ozone retrieval, requires detailed investigation.

Purpose of the Study:

• To calculate single-scattering and multiple-scattering lidar signals for a spaceborne DIAL system.
• To assess the impact of multiple scattering on ozone retrieval at 305/315 nm wavelengths.
• To evaluate the influence of aerosols and Rayleigh extinction on ozone retrieval accuracy.

Main Methods:

• Simulated lidar signals using single-scattering and multiple-scattering approximations.
• Calculations performed for a spaceborne DIAL system operating at 305 nm (on-wavelength) and 315 nm (off-wavelength).
• Analysis conducted under various atmospheric conditions, including background stratospheric aerosol, planetary boundary layer aerosols, and cirrus cloud models.

Main Results:

• Multiple scattering effects were found to be negligible for stratospheric ozone retrieval with background stratospheric aerosol.
• In the planetary boundary layer under low-visibility conditions, multiple scattering led to overestimation in maritime aerosols and underestimation in urban/rural aerosols.
• Multiple scattering significantly hindered accurate ozone retrieval within cirrus clouds, with partial recovery and underestimation below them.

Conclusions:

• Multiple scattering significantly impacts ozone retrieval accuracy in the troposphere, particularly in aerosol-laden and cloudy conditions.
• The presence of aerosols and Rayleigh extinction also influences ozone retrieval, necessitating careful consideration in data analysis.
• Accurate global ozone monitoring using spaceborne DIAL requires sophisticated models that account for multiple scattering effects, especially in the lower atmosphere and under cloudy conditions.