Entanglement of near-surface optical turbulence to atmospheric boundary layer dynamics and particulate concentration: implications for optical wireless communication systems

Abstract

Localized reduction in optical turbulence due to enhanced atmospheric heating caused by the solar absorption of aerosol black carbon (BC) is reported. Immediate response of atmospheric turbulence to BC-induced atmospheric warming strongly depends on the available solar radiation (time of the day), BC concentration, and atmospheric boundary layer dynamics. Besides the significant climate implications of a reduction in turbulence kinetic energy, a large reduction in the refractive index structure parameter ( C n 2 ) resulting from BC-induced warming would affect the atmospheric propagation of laser beams. Interestingly, aerosols contribute significantly (up to 25%) to the signal deterioration in optical wireless communication systems during convectively stable atmospheric conditions when higher signal-to-noise ratios are expected otherwise due to the reduced thermal convection. Competing effects of the fractional contributions of aerosol extinction and scintillations on beam attenuation are reported; daytime being largely dominated by scintillation effects while the nighttime being dependent on the ambient aerosol concentration as well. We put forward the entanglement of optical turbulence to aerosol concentration, atmospheric boundary layer dynamics, and surface-reaching solar radiation, and discuss the possible implications for optical propagation.

Comprehensive investigation of the atmospheric Modulation Transfer Function (MTF) for satellite imaging payloads: considering turbulence and aerosol effects over Tehran

“…Some research has focused on optical turbulence in the surface layer using the Monin-Obukhov similarity theory (MOST), such as the work by Ricklin [70] in 2004 which yielded good results for specific times, locations, and conditions. Also, many recent studies have investigated the surface layer C n 2 for laser propagation using different methods such as neural networks and other machine learning algorithms in various locations and situations [71][72][73]. Optical turbulence near the ground shows dependence on additional parameters compared to the free atmosphere, such as relative humidity, vegetation, and urban structures [72].…”

“…Also, many recent studies have investigated the surface layer C n 2 for laser propagation using different methods such as neural networks and other machine learning algorithms in various locations and situations [71][72][73]. Optical turbulence near the ground shows dependence on additional parameters compared to the free atmosphere, such as relative humidity, vegetation, and urban structures [72].…”

Full-duplex transmission of multi-Gb/s subcarrier multiplexing and 5G NR signals in 39 GHz band over fiber and space

“…Therefore, the wavelength dependence of AT effect is negligible. Please note in this analysis we do not include fog influence [23] or the role of atmospheric aerosols on the FSO [24].…”

Land‐Atmosphere Interactions at a Semi‐Arid Region in the Deccan Plateau

“…A climate observatory was established in the second campus of the Indian Institute of Science located at Challakere (14.4° N, 76.6° E, ≈600 m amsl), where round the clock measurements of an array of meteorological variables are carried out (Satheesh et al., 2013). The site is about 200 km northwest from the metropolitan city of Bengaluru and is characterized by a vast and near‐flat terrain (Anand et al., 2020). It is located within the Deccan Plateau and falls in the dry zone on the leeward sides of the Western and Eastern Ghats during the ISM and Northeast monsoon, respectively.…”