https://w3id.org/np/RA8rtviiIgfWXmWYBSrDQGOBizUp8iYmyGqneHLfkJk1k
has assertion: assertion
has provenance: provenance
has publication info: pubinfo
type: Nanopublication
created: 2026-07-08T16:06:41.186Z
creator: Emily Regalado
license: https://creativecommons.org/licenses/by/4.0/
introduces: Observing and simulating the polarization neutral point dependence on atmospheric turbidity
was created at: nanodash.knowledgepixels.com

Observing and simulating the polarization neutral point dependence on atmospheric turbidity
creator: https://orcid.org/0000-0001-8988-8744
creator: https://orcid.org/0009-0005-5419-4829
creator: https://orcid.org/0009-0007-6692-3376
publisher: 045k5vt03
subject: SRAO_0000186
type: article
type: FAIRDigitalObject
comment: Atmospheric aerosols influence the polarization signature of the sky by scattering or absorbing skylight. Neutral points are features in the sky’s polarization where single and multiple scattering processes incoherently add, yielding a degree of polarization equal to zero. The zenith angle of these features is highly sensitive to atmospheric turbidity. DeLeon and Kupinski (2025) demonstrated a method for tracking the Babinet neutral point, located above the Sun, using the Ultraviolet Linear Stokes Imaging Polarimeter (ULTRASIP). This study furthers that work by analyzing the Babinet neutral point zenith changes across multiple days under varying atmospheric conditions, quantified by data from an Aerosol Robotic Network (AERONET) ground station. The AERONET data is used with the Generalized Retrieval of Atmosphere and Surface Properties (GRASP) open-source radiative transfer model to obtain simulated Babinet neutral point zenith angle changes. Comparisons of ULTRASIP field observations and AERONET-based GRASP simulations of the Babinet neutral point diurnal trajectories are presented to assess sensitivity to atmospheric turbidity. Both observations and simulations reproduce the expected diurnal trend of the Babinet neutral point moving farther from the Sun at lower solar zenith angles, although simulations systematically overestimate the zenith separation. Linear fits to the diurnal trajectories show moderate correlations between observed and simulated slopes (ρ = 0.522) and intercepts (ρ = 0.439), which increase when high aerosol loading days are excluded. Variations in slope and intercept correspond to changes in aerosol optical depth, single scattering albedo, and particle size distribution. These results demonstrate that Babinet neutral point tracking offers a quantifiable, sensitive approach for monitoring atmospheric turbidity and capturing day-to-day aerosol variability.
funder: 021nxhr62
end date: 17 Sept 2025
start date: 2024

sig
has algorithm: RSA
signed by: Emily Regalado