The neutrally stable atmospheric surface layer is used as a physical model of a very high Reynolds number, canonical turbulent boundary layer. Challenges and limitations with this model are addressed in detail, including the inherent thermal stratification, surface roughness and non-stationarity of the atmosphere. Concurrent hot-wire and sonic anemometry data acquired in Utah's western desert p...

The probability density functions (pdf’s) for the longitudinal and vertical velocities, temperature, their derivatives, and momentum and sensible heat fluxes were measured in the atmospheric surface layer for a wide range of atmospheric stability conditions. The measured pdf’s for both the velocity and the temperature fluctuations are near-Gaussian and consistent with corresponding laboratory m...

This study proposes a new methodology to estimate the Atmospheric Boundary Layer Height (ABLH), discriminating between Convective and Stable heights, based on machine learning algorithm known as Gradient Boosting Regression Tree. The proposed here uses first estimation of ABLH derived applying gradient method ceilometer signal several meteorological variables obtain values comparable those from...

The influence of the local terrestrial environment on nocturnal atmospheric CO2 measurements at a 329-m television transmitter tower (and a component of a CO2 monitoring network) was estimated with a tracer release experiment and a subsequent simulation of the releases. This was done to characterize the vertical transport of emissions from the surface to the uppermost tower level and how it is ...

in this paper meteorological conditions of some acute air pollution periods for the city of tehran have been considered. the data used were obtained from the air quality control company (aqcc) of municipality and from synoptic station of the institute of geophysics. initially some statistical methods were used to find the episodes for acute air pollution episodes, and then their meteorological ...

a proposed method for protecting carbon steel and hence reducing iron release in an aqueous solution saturated with h2s is presented in this paper. the method is based on forming a stable and resistant sulfide layer (pyrite, fes2, or pyrrhotite, fe(1-x)s, phase or a mixture of both) on the carbon steel surface. the study on the formation of the sulfide layer was carried out considering the effe...

Verification of two months, April and May 1997, of 48-h mesoscale model simulations of the atmospheric state around Greenland are presented. The simulations are performed with a modified version of The Pennsylvania State University–National Center for Atmospheric Research fifth-generation Mesoscale Model (MM5), referred to as the Polar MM5. Global atmospheric analyses as well as automatic weath...

Introduction Conclusions References Tables Figures Back Close Abstract Introduction Conclusions References Tables Figures Back Close Abstract The Martilli's urban parameterization scheme is improved and implemented in a mesoscale model in order to take into account the typical effects of a real city on the air temperature near the ground and on the surface exchange fluxes. The mesoscale model i...