35 research outputs found
Towards Open and Equitable Access to Research and Knowledge for Development
Leslie Chan and colleagues discuss the value of open access not just for access
to health information, but also for transforming structural inequity in current
academic reward systems and for valuing scholarship from the South
The Impact of Different Terrain Configurations on the Formation and Dynamics of Katabatic Flows: Idealised Case Studies
Simulations of Horizontal Roll Vortex Development Above Lines of Extreme Surface Heating
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Observations of sweepâejection dynamics for heat and momentum fluxes during wildland fires in forested and grassland environments
The vertical turbulent transfer of heat and momentum in the lower atmospheric boundary layer is accom-plished through intermittent sweep, ejection, outward interaction, and inward interaction events associated with turbulent updrafts and downdrafts. These events, collectively referred to as sweepâejection dynamics, have been studied extensively in forested and nonforested environments and reported in the literature. However, little is known about the sweepâejection dynamics that occur in response to turbulence regimes induced by wildland fires in forested and nonforested environments. This study attempts to fill some of that knowledge gap through analyses of turbulence data previously collected during three wildland (prescribed) fires that occurred in grassland and forested environments in Texas and New Jersey. Tower-based high-frequency (10 or 20 Hz) three-dimensional wind-velocity and temperature measurements are used to examine fre-quencies of occurrence of sweep, ejection, outward interaction, and inward interaction events and their actual contributions to the mean vertical turbulent fluxes of heat and momentum before, during, and after the passage of fire fronts. The observational results suggest that wildland fires in these environments can substantially change the sweepâejection dynamics for turbulent heat and momentum fluxes that typically occur when no fires are present, especially the relative contributions of sweeps versus ejections in determining overall heat and momentum fluxes