Iron Boltzmann factor LIDAR: proposed new remote-sensing technique for mesospheric temperature

Area of Science:

• Atmospheric Science
• Geophysics
• Remote Sensing

Background:

• Accurate temperature measurements in the middle atmosphere (30-100 km) are crucial for understanding atmospheric dynamics.
• Existing remote sensing techniques face challenges in achieving comprehensive temperature profiles in this region.

Purpose of the Study:

• To introduce a novel Laser Imaging, Detection, and Ranging (LIDAR) technique for precise middle atmospheric temperature measurement.
• To utilize the iron (Fe) layer and specific atomic transitions for inferring temperature.

Main Methods:

• The proposed LIDAR technique exploits the Fe layer (80-100 km altitude).
• Absolute temperatures are determined using the Maxwell-Boltzmann relationship from the ratio of LIDAR returns.
• Measurements involve exciting mesospheric Fe atoms at 372 nm (ground-state resonance) and 374 nm (thermally populated resonance).
• Simultaneous monitoring of Rayleigh signals and Fe fluorescence returns is employed.

Main Results:

• The technique allows for absolute temperature inference based on the ratio of specific Fe fluorescence signals.
• The chosen LIDAR wavelengths are suitable for capturing Rayleigh scattering signals from the middle atmosphere.
• Simulations indicate the capability to acquire a complete temperature profile from 30 to 100 km.

Conclusions:

• The developed LIDAR technique offers a promising method for middle atmospheric temperature profiling.
• This approach leverages atomic properties of iron and dual-wavelength excitation for accurate measurements.
• The simultaneous measurement of Rayleigh and Fe fluorescence signals enhances the potential for comprehensive atmospheric characterization.