Three-wavelength CO₂ differential absorption lidar for atmospheric temperature profiling at 1.57  µm

Area of Science:

• Atmospheric Science
• Remote Sensing
• Spectroscopy

Background:

• Accurate temperature profiling in the lower troposphere is crucial for weather and climate modeling.
• Existing remote sensing methods often face challenges with aerosol interference and water vapor sensitivity.

Purpose of the Study:

• To develop and validate a novel three-wavelength CO2-DIAL system for precise lower-tropospheric temperature and CO2 number density retrieval.
• To assess the system's performance in terms of accuracy, resolution, and robustness against atmospheric interference.

Main Methods:

• Utilized a three-wavelength CO2-DIAL system operating at 1.57 µm.
• Employed a self-consistent retrieval framework matching two independent CO2 densities from different absorption pairs.
• Conducted sensitivity analyses to evaluate aerosol scattering and water vapor interference.

Main Results:

• Simultaneous retrieval of temperature and CO2 number density was achieved.
• Temperature uncertainty was demonstrated to be better than 0.8 K across altitudes from 0.4 to 3.1 km.
• Negligible water vapor interference (<0.05 K) and independence from aerosol scattering ratio were confirmed.

Conclusions:

• The developed CO2-DIAL system offers a robust and accurate method for lower-tropospheric temperature measurements.
• The system's insensitivity to aerosols and water vapor enhances its reliability for atmospheric profiling.
• This technology holds significant potential for improving meteorological forecasting and climate studies.