Assessing Local Snow Variability Using a Network of Ultrasonic Snow Depth Sensors

During the 2009-2010 winter season, 21 inexpensive ultrasonic snow depth (USD) sensors were constructed and installed, in addition to two standard Judd USD sensors, at Treeline and Lower Deer Point sites located within the snow dominated Dry Creek Experimental Watershed, near Boise, Idaho. Six USD sensors, including a single Judd Communications USD sensor, were installed at the Treeline site along a northeast to southwest transect of the small 0.02 km2 catchment. Seventeen USD sensors, including a single Judd Communications USD sensor, were installed at Lower Deer Point in a randomized stratified pattern with respect to aspect and vegetation to reflect the nature of the ridge knob site. The purpose of this study was to investigate the local variability of SWE in the form of new fallen snow and assess how well data obtained from standard precipitation gauges represent local conditions. Spatial distributions of new snow depth were converted to estimated new SWE, based off of the relationship between USD measurements of new fallen snow depth and new fallen snow density estimates collected from storm boards placed in a stratified pattern with respect to USD site locations at Treeline and Lower Deer Point. In all, on a storm by storm basis, Lower Deer Point and Treeline precipitation gauges were found to underestimate water accumulation by approximately 16% to 30% and 18% to 26%, respectively. These findings are consistent with what is typically observed from uncorrected weighing-type precipitation gauge measurements. Additionally, variability associated with new fallen SWE estimates was found to increase with increasing snow accumulation totals, which was consistent with previous field studies

Survey on basic knowledge about exposure and potential environmental and health risks for selected nanomaterials

På basis af en litteraturundersøgelse gives en generel beskrivelse samt en miljø- og sundhedsprofil af 7 nanomaterialer. De undersøgte nanomaterialer er udvalgt på grund af forventet stor anvendelse eller særlige miljø- og sundhedsegenskaber. Fullerener, jern, sølv, nanoler samt titan-, cerium- og silicium dioksid har indgået i undersøgelsen. Det påpeges, at der er lille sandsynlighed for, at nuværende anvendelser af nano-jern og nanoler kan give uforudsete, nanorelaterede miljø- eller sundhedsproblemer. For de øvrige nanomaterialer, er der områder, hvor der kan være grund til opmærksomhed og til af skaffe mere viden, selvom der ikke er identificeret konkret risiko i forbindelse med nuværende anvendelser af nogen af de 7 undersøgte nanomaterialer.Based on a literature review this report provides a general description as well as an environmental and health profile of 7 nanomaterials. The examined nanomaterials are selected because of expected high use or specific environmental and health properties. Fullerenes, iron, silver, nanoclay and titanium-, cerium-, and silicondioxides were studied in the project. Based on current uses, it is concluded that current applications of nano-iron and nanoclay can not cause unexpected “nano-associated” health or environmental problems. Although no specific risk associated with current uses of any of the 7 other nanomaterials were identified, there are areas where there may be reason for attention and thus need for more knowledge