Performance Evaluation of a New Dual-Polarization Microphysical Algorithm Based on Long-Term X-Band Radar and Disdrometer Observations

Abstract Accurate estimation of precipitation at high spatial and temporal resolution of weather radars is an open problem in hydrometeorological applications. The use of dual polarization gives the advantage of multiparameter measurements using orthogonal polarization states. These measurements carry significant information, useful for estimating rain-path signal attenuation, drop size distribution (DSD), and rainfall rate. This study evaluates a new self-consistent with optimal parameterization attenuation correction and rain microphysics estimation algorithm (named SCOP-ME). Long-term X-band dual-polarization measurements and disdrometer DSD parameter data, acquired in Athens, Greece, have been used to quantitatively and qualitatively compare SCOP-ME retrievals of median volume diameter D0 and intercept parameter NW with two existing rain microphysical estimation algorithms and the SCOP-ME retrievals of rain rate with three available radar rainfall estimation algorithms. Error statistics for rain rate estimation, in terms of relative mean and root-mean-square error and efficiency, show that the SCOP-ME has low relative error if compared to the other three methods, which systematically underestimate rainfall. The SCOP-ME rain microphysics algorithm also shows a lower relative error statistic when compared to the other two microphysical algorithms. However, measurement noise or other signal degradation effects can significantly affect the estimation of the DSD intercept parameter from the three different algorithms used in this study. Rainfall rate estimates with SCOP-ME mostly depend on the median volume diameter, which is estimated much more efficiently than the intercept parameter. Comparisons based on the long-term dataset are relatively insensitive to path-integrated attenuation variability and rainfall rates, providing relatively accurate retrievals of the DSD parameters when compared to the other two algorithms

Developing a Science Gateway for Physical Activity Lifelong Modelling & Simulation

There are major health concerns that relate to the lack of physical activity in a general population. In the UK, a major study has been carried out that brought together health assessment audits across a range of health conditions influenced by physical activity (cardiovascular diseases, musculoskeletal conditions, mental health, etc.) This was used to create PALMS (Physical Activity Lifelong Modelling & Simulation). PALMS is a microsimulation that predicts the lifelong physical activity behaviour of a population taking into account individual characteristics and their effect on physical activity over time. The model produces individual and aggregated quantitative outputs for quality of life and health conditions related costs. Thus, PALMS can be used to assess the impact of physical activity on the aforementioned health conditions across the population

An innovative radiation hardened CAM architecture

An innovative Content Addressable Memory (CAM) cell with radiation hardened (RH) architecture is presented. The RH-CAM is designed using a commercial 28 nm CMOS technology. The circuit has been simulated in worst-case conditions, and the effects due to single particles have been analyzed by injecting a current pulse into a circuit node. The proposed architecture is suitable for real-time pattern recognition tasks in harsh environments, such as front-end electronics in the ATLAS experiment at the Large Hadron Collider (LHC) and in space applications

Distribution of dissolved inorganic carbon and related parameters in the Thermaikos Gulf (Eastern Mediterranean)

Data on the distribution of dissolved inorganic carbon (measured as TCO2) and related parameters in the Thermaikos Gulf were obtained during May 1997. High TCO2 concentrations were recorded close to the bottom, especially in the northern part of the gulf, as a result of organic matter remineralisation. The positive relatively good correlation between TCO2 and both apparent oxygen utilisation (AOU) and phosphate at the last sampling depth confi rmed the regenerative origin of a large proportion of TCO2. The comparatively conservative behaviour of alkalinity, together with the relatively low value of the homogenous buffer factor β (β = ∂lnfCO2/∂lnTCO2) revealed that calcifi cation or carbonate dissolution takes place on a very small scale, simultaneously with the organic carbon production. The correlations between fCO2 and chlorophyll α, as well as AOU and the surface temperature, revealed that the carbon dioxide fi xation through the biological activity is the principal factor that modulates the variability of fCO2. A rough first estimate of the magnitude of the air-sea CO2 exchange and the potential role of the Thermaikos Gulf in the transfer of atmospheric CO2 was also obtained. The results showed that during May 1997, the Thermaikos Gulf acted as a weak sink for atmospheric CO2 at a rate of -0.60 - -1.43 mmol m-2 d-1, depending on which formula for the gas transfer velocity was used, and in accordance to recent reports regarding other temperate continental shelves. Extensive study of the dissolved inorganic carbon and related parameters, and continuous shipboard measurements of fCO2 a and fCO2 w during all seasons are necessary to safely quantify the role of the Thermaikos Gulf in the context of the coastal margins CO2 dynamics

Stabilization of a Failed Highway Slope: A Multi-Phased Approach

A county road department in Southeastern Michigan was faced with the problem of stabilizing a slope along the Clinton River supporting a heavily trafficked roadway. The roadway and supporting slope had performed satisfactorily for over 50 years. However, a reinforced concrete seawall that had partially supported the slope deteriorated over time, contributing to progressive failure of the slope and resulting damage to the roadway. The site is situated within the glacial lake plain district of Southeastern Michigan. The site geology consists of approximately 7 feet of over-consolidated clays underlain by approximately 17 feet of normally consolidated glacial-lacustrine clays. Below the normally consolidated clay, highly over-consolidated sandy clay till and dense fine to medium sands are present. The sands contain a confined aquifer with a hydrostatic head on the order of 20 feet. The 14-foot high, 35 degree slope has experienced progressive, creep type movement since approximately the year 2000 resulting in settlement and cracking of the roadway shoulder and pavement. Maintenance procedures to maintain serviceability of the roadway created increased surcharge loads that appear to have precipitated further creep movement. Our analyses indicated the unreinforced slope possessed a factor of safety of approximately one or less with respect to global and direct sliding failure mechanisms under both drained and undrained conditions. A number of alternatives were considered to obtain the desired factory of safety values. Upon analysis, these alternatives were not considered satisfactory due to failure to meet the project objectives, typically cost and/or failure to obtain the desired factor of safety against slope failure. A multi-phased approach was selected that was aimed at both reducing the destabilization forces as well as increasing the resisting forces by replacing the upper portion of the slope with geogrid-reinforced lightweight, angular blast furnace slag, and intercepting the slope failure surface with passive piles extending into the highly over-consolidated sandy clay till and/or dense sands. This approach allowed the project objective to be met with the work being accomplished on schedule and within budget. A cost savings of approximately $400,000 was realized with respect to other stabilization alternatives