Humidity's influence on visible region refractive index structure parameter C_n^2

Abstract

In the near-infrared and visible bandpasses optical propagation theory conventionally assumes that humidity does not contribute to the effects of atmospheric turbulence on optical beams. While this assumption may be reasonable for dry locations, we demonstrate that there is an unequivocal effect owing to the presence of humidity upon the strength of turbulence parameter, C n 2 , from data collected in the Chesapeake Bay area over 100 m length horizontal propagation paths. We describe and apply a novel technique, Hilbert phase analysis, to the relative humidity, temperature, and C n 2 data to show the contribution of the relevant climate variable to C n 2 as a function of time.

Modelling the Concentration Distributions of Aerosol Puffs Using Artificial Neural Networks

“…In addition, refractive index is a reflection of the inhomogeneity or turbulence in the atmosphere, and the corresponding refractive index structure constant, C 2 n , is the parameter most commonly used to describe the intensity of atmospheric turbulence (Tatarskii 1961). The C 2 n values for visible and near-infrared radiation in air depend on humidity, as well as pressure and temperature (Chang et al 2007). The C 2 n value, together with TKE and Obukhov length, as well as other meteorological measurements, were selected to represent the state of atmospheric stability or turbulence conditions, allowing their direct influences on the concentration distribution predictions to be determined.…”

Probability density function of the intensity of a laser beam propagating in the maritime environment

“…A medium that involves both clear air optical turbulence and particle absorption/ scattering, is the atmosphere in the maritime environment. A large volume of water creates a situation where water droplets, bio-particles and various types of aerosols are present in abundance [10]. Maritime atmospheric environment has been not been studied extensively from the perspective of optical characterization [11][12][13].…”

Comparing horizontal path C2n measurements over 0.6 km in the tropical littoral environment and in the desert

“…We have obtained weak turbulence optical C 2 n measurements, integrated over 600m horizontal paths in both the littoral environment in the Caribbean region (southwest Puerto Rico) and in the high desert of central New Mexico. The Puerto Rico littoral data record covers the period between February 4 to March 13, 2007 (year days 35 to 72).…”