Abstract

Accurate fog prediction in densely urbanized cities poses a challenge due to the complex influence of urban morphology on meteorological conditions in the urban roughness sublayer. This study implemented a coupled WRF-Urban Asymmetric Convective Model (WRF-UACM) for Delhi, India, integrating explicit urban physics with Sentinel-updated USGS land-use and urban morphological parameters derived from the UT-GLOBUS dataset. When evaluated against the baseline Asymmetric Convective Model (WRF-BACM) using Winter Fog Experiment (WiFEX) data, WRF-UACM significantly improved urban meteorological variables such as diurnal variations in 10-m wind speed, 2-m air temperature (T2), and 2-m relative humidity (RH2) during a fog event. UACM also demonstrates improved accuracy in simulating temperature and significantly reducing biases for wind speed and daytime RH2 under clear sky conditions. UACM reproduced the nighttime urban heat island effect within the city, showing realistic diurnal heating and cooling patterns that are important for accurate fog onset and duration. UACM effectively predicts the onset, evolution, and dissipation of fog, aligning well with observed data and satellite imagery. Compared to WRF-BACM, WRF-UACM reduces the cold bias soon after sunset, thus improving the fog onset error by ∼3 hr. This study highlights the UACM's potential to improve fog prediction and its application in operational settings. with further investigation into different fog types, the UACM can provide crucial insights for preventive measures and reducing disruptions in urban areas.

Department(s)

Biological Sciences

Publication Status

Full Access

Comments

India Meteorological Department, Grant None

Keywords and Phrases

boundary layer meteorology; fog; urban canopy parameterization; urban heat island; urban morphological parameters; WRF model

International Standard Serial Number (ISSN)

2169-8996; 2169-897X

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2025 American Geophysical Union; Wiley, All rights reserved.

Publication Date

28 Oct 2024

Included in

Biology Commons

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