The characterization of turbulent heat and moisture transport during a gust-front event over the Indian peninsula

Autor: Subharthi Chowdhuri, Kiran Todekar, Thara V. Prabha
Rok vydání: 2021
Předmět:
Zdroj: Environmental Fluid Mechanics. 21:907-924
ISSN: 1573-1510
1567-7419
Popis: The ramifications of gust-front on atmospheric surface layer (ASL) turbulence is a vexing issue, with nearly no information available over the Indian region where such events are not uncommon. Over the Indian peninsula, Chowdhuri et al. (Environ. Fluid Mech. 21(1):263–281, 2021) have shown that, the cold pool associated with the gust-front creates two distinct regimes in ASL turbulence, where the temperature fluctuations display contrasting behavior. To evaluate the corresponding impacts on the moisture fluctuations and turbulent heat and moisture transport, we extend our analysis by using the same field-experimental dataset of Chowdhuri et al. (2021). We discover that, the topology of the turbulent structures which govern the temperature and moisture fluctuations clearly exhibit a regime-wise distinction. In the first regime, the structures in temperature and moisture fluctuations are significantly inclined in the vertical, while demonstrating a self-similarity in their time scales by being related through a power-law distribution. However, in the second regime, the vertical inclination disappears for the temperature structures with hardly any change observed for the moisture. Moreover, the power-law exponents of the turbulent temperature time scales remain sensitive to the regimes, although no such effect is visible in the power-law character of the moisture time scales. Additionally, the dissimilarity in the heat and moisture transport is investigated through a novel polar-quadrant based approach that separates the phases and amplitudes of the flux-transporting motions.
Databáze: OpenAIRE
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