Surface layer turbulence processes in low wind speeds over land

An Analysis Of Sonic Anemometer Observations In Low Wind Speed Conditions

“…Deaves and Lines (1998), on the basis of data from 1981 to 1990 from a selection of United Kingdom inland sites, showed that the annual average frequency of LWS conditions, defined as u < 2:05 m s À1 (4 knots), ranged from 9.2% to 29.7%. Agarwal et al (1995) reported that calm conditions occur quite frequently in the tropics. Also in northern European countries such conditions can be considered as typical (Kukkonen et al, 2001).…”

Aerodynamic drag coefficient over equatorial coastal industrialized and urban areas

“…This is logical since sampling was done within the URS. It was also discovered that Taylor's frozen theory hypothesis (Agarwal et al, 1995) applies at both sites since turbulence intensities measured were o0.5 during all observations. Bin Yusup et al (2008) also noted that most of turbulence in this area was dominated by mechanical factors such as surface roughness with slight convective motions caused by the underlying surface, and influence of the channeled land and sea breezes.…”

“…Even though, ASL data for these models in developing countries such as Malaysia and other equatorial areas are few and far between, with the majority of data were collected from countries in the European continent and in the Americas (Bin Yusup et al, 2008;Patil, 2006). Some studies have been conducted in Asia where the most relevant work are from India (Agarwal et al, 1995;Krishnan and Kunhikrishnan, 2002;Patil, 2006;Ramana et al, 2004;Rao et al, 1996). Furthermore, interests in the effects of changing surface condition on the various atmospheric layers have risen in the past decade because of the increasing reliance on air pollution and weather forecasting models that depend on obtaining accurate parameterization of the various properties of the atmospheric layers.…”

Simulation of Atmospheric Boundary Layer Characteristics during Indian Summer Monsoon using Observations from Monsoon Trough Boundary Layer Experiment at Jodhpur, India

“…The boundary layer processes under different atmospheric stability conditions were studied through modelling or observations made from several field experiments like MONsoon EXperiment (MONEX)-1979 and routine meteorological data RAMAN, 1985, 1988;MANJU KUMARI, 1985;VERNEKAR et al, 1991;GAMO et al, 1994) and IIT Diffusion experiment (AGGARWAL et al, 1995;YADAV et al, 1996). The boundary layer turbulence was studied using the measurements obtained from the meteorological tower (RAMAN et al, 1990;AGGARWAL et al, 1995;YADAV et al, 1996) and through monostatic sodars (SINGAL et al, 1982;. A high resolution primitive equation onedimensional model has been used to study the ABL over the monsoon trough region by POTTY et al (1997) and it found that Turbulent Kinetic Energy (TKE) increases from the eastern side of the monsoon trough to the western sector.…”