The relation of spring pollen release to weather in Fairbanks, AK

Thesis (M.S.) University of Alaska Fairbanks, 2012Twenty-three years of pollen data for Fairbanks have been analyzed and related to meteorological data (temperature, wind, relative humidity and precipitation). The purpose of this research is to develop quantitative statistical relationships between weather parameters and the timing and magnitude of pollen release for four taxa native to the Fairbanks area (birch, alder spruce and grass). During the spring and early summer in Fairbanks, dry, sunny and breezy days are common. These conditions are ideal for establishing an unstable boundary layer and its accompanying convective circulation, which can loft large quantities of pollen into the atmosphere. The timing of pollen release varies from season to season by as many as 24 days. Growing degree days based upon daily maximum temperatures and daily minimum relative humidity are the parameters which best define the timing of the onset of significant pollen release. The day-to-day concentration of pollen and the seasonal totals of pollen released can vary by more than an order of magnitude. Weather plays an important part in this because the release of pollen is a result of a drying process accompanied by turbulent circulation, which disperses the pollen

Variable illumination and invariant features for detecting and classifying varnish defects

This work presents a method to detect and classify varnish defects on wood surfaces. Since these defects are only partially visible under certain illumination directions, one image doesn\u27t provide enough information for a recognition task. A classification requires inspecting the surface under different illumination directions, which results in image series. The information is distributed along this series and can be extracted by merging the knowledge about the defect shape and light direction