Rainfall observations using dual-polarization radar coupled with a drop motion and evaporation model

Abstract from short.pdf file."December 2013.""A Thesis presented to the Faculty of the Graduate School at the University of Missouri--Columbia In Partial Fulfillment of the Requirements for the Degree Master of Science."Thesis supervisor: Dr. Neil Fox.Measuring spatial coverage of rainfall is important for several disciplines; unfortunately, rainfall data via rain gauges is very limited in spatial coverage. The best remote sensing tool available for rainfall estimation is radar, but this has many limitations, especially for locations far from the radar. Central Missouri is one such location and was the focus of this study. For this study a computer program was created to determine the effectiveness of radar rainfall estimation techniques in Central Missouri. Two groups of techniques were evaluated. The first group was conventional formulas. These were simple formulas based on combinations of three available radar parameters: reflectivity, differential reflectivity, and specific phase differential. The second group was designed specifically for this project. This group consisted of the "trace techniques", where individual raindrops were traced back to the location where they interacted with the radar beam. In this process the program used high resolution model data to calculate horizontal drift and raindrop evaporation. The results from this study indicated a modest improvement in radar rainfall estimation performance from the introduction of raindrop evaporation; this improvement was on the order of 10%. The conclusion was made that the effects of raindrop evaporation were significant enough to warrant the inclusion of high resolution model data in the radar rainfall estimation process. Less conclusive were the effects of horizontal drift on radar rainfall estimation.Includes bibliographical references (pages 208-211)

The effects of weather classification on regression-based downscaling of daily temperature extrema in the United States

The focus of this dissertation was on the role played by weather classification in regression-based downscaling of daily temperature extrema. Three closely related studies were conducted, each using a different criterion for weather classification. The primary objective of all these studies was to evaluate changes in downscaling model performance as meteorological properties of the training periods were varied. This objective was of interest due to potential improvements in downscaling performance when accounting for non-static relationships between predictors and predictands. The first study used the time of day of the temperature extremum as the weather classification, while the third study used the direction of the wind as the weather classification. The second study used temperature as the weather classification, with a focus on possible consequences for downscaling in warmer conditions that were not present in the training conditions. Results from all three studies indicated that downscaling performance had the potential to be affected by the weather conditions seen in the training periods.Includes bibliographical references

Atrazine Influence on Northern Pike Sperm Motility and Viability in Minnesota

Concern has been noted by fish hatchery biologists with the Department of Natural Resources that southern Minnesota northern pike Esox lucius populations have exhibited reduced hatching rates, a trend not occurring with northern Minnesota pike populations. The chemical atrazine is a frequently used herbicide in Minnesota and has been found to cause gonadal dysgenesis and reproductive development issues in amphibians and fish. Sperm, length, and age data were collected from northern pike in four Minnesota lakes. Water samples were obtained from two of the lakes to test for atrazine. Test results indicated atrazine concentrations0.10 and r2 \u3c 0.06 for all regressions). Sperm motility reductions in northern pike could be related to declining populations and warrants further research

REGULATION OF CARBON SEQUESTRATION AND WATER USE IN A OZARK FOREST: PROPOSING A NEW STRATEGICALLY LOCATED AMERIFLUX TOWER SITE IN MISSOURI

by June 14, 2004, the MOFLUX site was fully instrumented and data streams started to flow. A primary accomplished deliverable for the project period was the data streams of CO{sub 2} and water vapor fluxes and numerous meteorological variables (from which prepared datasets have been submitted to the AmeriFlux data archive for 2004-2006, Additionally, measurements of leaf biochemistry and physiology, biomass inventory, tree allometry, successional trends other variables were obtained

REGULATION OF CARBON SEQUESTRATION AND WATER USE IN A OZARK FOREST: PROPOSING A NEW STRATEGICALLY LOCATED AMERIFLUX TOWER SITE IN MISSOURI

by June 14, 2004, the MOFLUX site was fully instrumented and data streams started to flow. A primary accomplished deliverable for the project period was the data streams of CO{sub 2} and water vapor fluxes and numerous meteorological variables (from which prepared datasets have been submitted to the AmeriFlux data archive for 2004-2006, Additionally, measurements of leaf biochemistry and physiology, biomass inventory, tree allometry, successional trends other variables were obtained

Immunotoxicity of poly (lactic-co-glycolic acid) nanoparticles: influence of surface properties on dendritic cell activation

International audienc

Immunogenicity of long-lasting recombinant factor VIII products

International audienceReplacement therapy for patients with hemophilia A using plasma-derived or recombinant factor VIII (FVIII) is complicated by the short half-life of the FVIII products and by the occurrence of neutralizing antibodies in a substantial number of patients. In the recent years, enormous efforts have been invested to develop new generations of coagulation factors with extended half-lives. Presumably, the use of long-lasting FVIII products should reduce the frequency of administration to the patients and drastically improve their quality of life. The question of their immunogenicity remains however unanswered as yet. The present review proposes a summary of the different strategies developed to enhance the half-life of FVIII, including fusion of FVIII to the Fc fragment of the human IgG1 or to human serum albumin, or attachment of polyethylene glycol. Based on the available literature, we hypothesize on the potential benefits or risks associated with each of the latter strategies in terms of immunogenicity of the newly derived hemostatic drugs

The fundamental equation of eddy covariance and its application in flux measurements

A fundamental equation of eddy covariance (FQEC) is derived that allows the net ecosystem exchange (NEE) N̅s of a specified atmospheric constituent s to be measured with the constraint of conservation of any other atmospheric constituent (e.g. N2, argon, or dry air). It is shown that if the condition │N̅s│ ˃˃ │X̅s│ │N̅co2│is true, the conservation of mass can be applied with the assumption of no net ecosystem source or sink of dry air and the FQEC is reduced to the following equation and its approximation for horizontally homogeneous mass fluxes: N̅s = c̅dw’X’s│h + ∫h0 c̅d(z) ∂Xs/∂t dz + ∫h0 [X̅s (z)- X̅s (h)] ∂̅c̅d̅/∂t dz = c̅d̅(h) {w̅’X̅’s│h + ∫h0 ∂Xs/∂t dz}. Here w is vertical velocity, c molar density, t time, h eddy flux measurement height, z vertical distance and Xs= cs/cd molar mixing ratio relative to dry air. Subscripts s, d and CO2 are for the specified constituent, dry air and carbon dioxide, respectively. Primes and overbars refer to turbulent fluctuations and time averages, respectively. This equation and its approximation are derived for non-steady state conditions that build on the steady-state theory of Webb, Pearman and Leuning (WPL; Webb et al., 1980. Quart. J. R. Meteorol. Soc. 106, 85–100), theory that is widely used to calculate the eddy fluxes of CO2 and other trace gases. The original WPL constraint of no vertical flux of dry air across the EC measurement plane, which is valid only for steady-state conditions, is replaced with the requirement of no net ecosystem source or sink of dry air for non-steady state conditions. This replacement does not affect the ‘eddy flux’ term c̅d̅w̅’X̅’s s but requires the change in storage to be calculated as the ‘effective change in storage’ as follows: ∫h0 ∂̅c̅s̅/ ∂̅t̅ dz – X̅s(h) ∫h0 ∂̅c̅d̅/∂t dz = ∫h0 c̅d̅ (z) - ∂Xs/∂t dz + ∫h0 [X̅s (z)- X̅s (h)] ∂̅c̅d̅/∂t dz= c̅d (h) ∫h0 ∂Xs/∂t dz. Without doing so, significant diurnal and seasonal biases may occur. We demonstrate that the effective change in storage can be estimated accurately with a properly designed profile of mixing ratio measurements made at multiple heights. However further simplification by using a single measurement at the EC instrumentation height is shown to produce substantial biases. It is emphasized that an adequately designed profile system for measuring the effective change in storage in proper units is as important as the eddy flux term for determining NEE

A new paradigm of quantifying ecosystem stress through chemical signatures

Stress-induced emissions of biogenic volatile organic compounds (VOCs) from terrestrial eco- systems may be one of the dominant sources of VOC emissions worldwide. Understanding the ecosystem stress response could reveal how ecosystems will respond and adapt to climate change and, in turn, quan- tify changes in the atmospheric burden of VOC oxidants and secondary organic aerosols. Here, we argue, based on preliminary evidence from several opportunistic measurement sources, that chemical signatures of stress can be identified and quantified at the ecosystem scale. We also outline future endeavors that we see as next steps toward uncovering quantitative signatures of stress, including new advances in both VOC data collection and analysis of "big data.