The structure parameter of temperature induced by surface heterogeneity in the convective boundary layer: Idealised WRF large eddy simulations
Abstract
Blending height signifies the height and the extent to which the convective boundary layer (CBL) is influenced by surface heterogeneity. Understanding how a heterogeneous surface affects the CBL helps to interpret remote-sensing measurements derived from the spatial-averaged quantities, which normally assume homogeneity. The structure parameter of temperature is one of the most important parameters related to the measurement of surface heat fluxes. We investigate this parameter using the Weather Research and Forecasting (WRF) model in large eddy simulation (LES) mode. A patchy heterogeneous pattern of both urban and park areas is configured at the surface. A homogeneous surface case is also simulated as a reference case for comparison. The impact of length scale of surface heterogeneity has been examined. There is clear evidence of the influence of surface heterogeneity on the structure parameter of temperature at lower levels. The blending height for the structure parameter of temperature varies with the length scale of the heterogeneous input. We propose this as a minimum height, above which measurements intended for spatial averaging are better to take place, in order to reduce the influence of surface heterogeneity.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A13N3139Z
- Keywords:
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- 3307 Boundary layer processes;
- ATMOSPHERIC PROCESSES;
- 3322 Land/atmosphere interactions;
- ATMOSPHERIC PROCESSES;
- 3379 Turbulence;
- ATMOSPHERIC PROCESSES;
- 0426 Biosphere/atmosphere interactions;
- BIOGEOSCIENCES