Index Geophysics

Similarity analysis of turbulent transport and dissipation for momentum, temperature, moisture, and CO2 during BLLAST

The budget equation components for turbulent kinetic energy (TKE) and the variances of virtual potential temperature, specific humidity, and specific CO₂ content have been estimated using the Inertial Dissipation and Eddy Covariance methods. A discussion with four examples is provided about the normalization used for comparing different tracer spectra, divided by the respective characteristic scale squared. A total of 124 high frequency sample segments of a 30-min period from 20 days of the Boundary Layer Afternoon and Sunset Turbulence field campaign were used in order to provide parameterizations for the dimensionless dissipation and residual (i.e. total transport) components as a function of the Atmospheric Surface Layer (ASL) stability parameter, &zeta;. The results show a similar linear relation for all tracers variance dissipation components, &Phi;^<i>D</i>_&chi; &cong; 0.4 + 0.2 &zeta;, during the convective ASL, i.e. &minus;1 < &zeta; < &minus;0.1. Although parameterizations were also proposed for the dimensionless dissipation rate of TKE and tracer variances during stable ASL, we conclude that in this regime, other mechanisms in addition to &zeta; may be significantly important. In the stable and near-neutral ASL stability regimes, the transport component for different tracers may not be considered the same. In these conditions, the dissipation component of TKE and tracer variances can have the same magnitude as the other terms in their respective budget equation.

Hackerott, João A.

Paskyabi, Mostafa Bakhday

Kral, Stephan T.

Reuder, Joachim

Oliveira, Amauri P.

Marques Filho, Edson P.

Mesquita, Michel d. S.

Camargo, Ricardo

2018-08-11

Text

application/pdf

10.5194/acp-2015-1061

https://acp.copernicus.org/preprints/acp-2015-1061/

eISSN: 1680-7324

eng