We report measurements of the Nusselt number, Nu, in turbulent thermal convection in a cylindrical container of aspect ratio 4. The highest Rayleigh number achieved was Ra=2× 10. Except for the last half a decade or so of Ra, experimental conditions obey the Boussinesq approximation accurately. For these conditions, the data show that the logNu–logRa slope saturates at a value close to 1/3, as ...

Aim In this study, we evaluated the ®re-forest mosaic of a mixed conifer forest landscape by testing the hypothesis that pre-®re suppression ®re regime parameters vary with species composition (tree species), and environment (i.e. slope aspect, slope position, elevation). Location Our study was conducted in the 1587 ha Cub Creek Research Natural Area (CCRNA), Lassen National Forest, CA, USA. Me...

Topographic asymmetry, that is, differences in the morphology of landscapes as a function of slope aspect, can be used to infer ecohydrogeomorphic feedback relationships. In this study, we document the dependence of topographic gradients and drainage densities on slope aspect and time/age in four Quaternary cinder cone fields in Arizona, Oregon, and California. Cinder cones are particularly use...

Plant ecologists have recognized the importance of solar radiation for decades but have difficulty measuring it on plots. Proxies recorded on the ground or geographical information system (GIS) indices processed with a digital elevation model (DEM) have generally been used. Here we compare the efficiency of different methods of estimating spatially distributed topographic solar radiation, from ...

Simplified models relating pitch and roll angle measurements of a roving vehicle to terrain slope and vehicle attitude were developed. The simplified models are based on previously published models by Rowe and Spencer [1] and Yang et al. [2]. These simplified models are easier to implement using microcontroller technology reducing the number of trigonometric function calculations, improving pro...

habitat associations of wild sheep, alborz red sheep (ovis orientalis gemelini x ovis orientalis arkali ), in khojir and sorkheh hesar national parks were studied over three seasons (spring, autumn and winter) in 2000. the position of observed maternal groups (including ewe with lamb) and male groups (including rams, barren ewes and juveniles) were determined on topographical maps during the fi...