ALBERT

Description: ABSTRACT With high-resolution topography and imagery in fluvial environments, the potential to quantify physical fish habitat at the reach-scale has never been better. Increased availability of hydraulic, temperature and food availability data and models have given rise to a host of species and life stage specific ecohydraulic fish habitat models ranging from simple, empirical habitat suitability curve driven models, to fuzzy inference systems to fully mechanistic bioenergetic models. However, few examples exist where such information has been upscaled appropriately to evaluate entire fish populations. We present a framework for applying such ecohydraulic models from over 905 sites in 12 sub-watersheds of the Columbia River Basin (USA), to assess status and trends in anadromous salmon populations. We automated the simulation of computational engines to drive the hydraulics, and subsequent ecohydraulic models using cloud computing for over 2075 visits from 2011 to 2015 at 905 sites. We also characterize each site's geomorphic reach type, habitat condition, geomorphic unit assemblage, primary production potential and thermal regime. We then independently produce drainage network-scale models to estimate these same parameters from coarser, remotely sensed data available across entire populations within the Columbia River Basin. These variables give us a basis for imputation of reach-scale capacity estimates across drainage networks. Combining capacity estimates with survival estimates from mark-recapture monitoring allows a more robust quantification of capacity for freshwater life stages (i.e. adult spawning, juvenile rearing) of the anadromous lifecycle. We use these data to drive life cycle models of populations, which not only include the freshwater life stages but also the marine and migration life stages through the hydropower system. More fundamentally, we can begin to look at more realistic, spatially explicit, tributary habitat restoration scenarios to examine whether the enormous financial investment on such restoration actions can help recover these populations or prevent their extinction.

Description: Lenticular wave clouds are used as a natural laboratory to estimate the linear and mass growth rates of ice particles at temperatures from −20° to −32°C and to characterize the apparent rate of ice nucleation at water saturation at a nearly constant temperature. Data are acquired from 139 liquid cloud penetrations flown approximately along or against the wind direction. A mean linear ice growth rate of about 1.4 μm s−1, relatively independent of particle size (in the range 100–400 μm) and temperature is deduced. Using the particle size distributions measured along the wind direction, the rate of increase in the ice water content (IWC) is calculated from the measured particle size distributions using theory and from those distributions by assuming different ice particle densities; the IWC is too small to be measured. Very low ice effective densities,