Revised Perturbation Statistics for the Global Scale Atmospheric Model

Magnitudes and scales of atmospheric perturbations about the monthly mean for the thermodynamic variables and wind components are presented by month at various latitudes. These perturbation statistics are a revision of the random perturbation data required for the global scale atmospheric model program and are from meteorological rocket network statistical summaries in the 22 to 65 km height range and NASA grenade and pitot tube data summaries in the region up to 90 km. The observed perturbations in the thermodynamic variables were adjusted to make them consistent with constraints required by the perfect gas law and the hydrostatic equation. Vertical scales were evaluated by Buell's depth of pressure system equation and from vertical structure function analysis. Tables of magnitudes and vertical scales are presented for each month at latitude 10, 30, 50, 70, and 90 degrees

How Interethnic Marriages Affect the Educational Attainment of Children: Evidence from a Natural Experiment

The allocation of Moluccan immigrants across towns and villages at arrival in the Netherlands and the subsequent formation of interethnic marriages resemble a natural experiment. The exogenous variation in marriage formation allows us to estimate the causal effect of interethnic marriages on the educational attainment of children from such marriages. We find that children from Moluccan fathers and native mothers have a higher educational attainment than children from ethnic homogeneous Moluccan couples or children from a Moluccan mother and a native father.interethnic marriages, educational attainment

Phase Description of Stochastic Oscillations

We introduce an invariant phase description of stochastic oscillations by generalizing the concept of standard isophases. The average isophases are constructed as sections in the state space, having a constant mean first return time. The approach allows to obtain a global phase variable of noisy oscillations, even in the cases where the phase is ill-defined in the deterministic limit. A simple numerical method for finding the isophases is illustrated for noise-induced switching between two coexisting limit cycles, and for noise-induced oscillation in an excitable system. We also discuss how to determine the isophases for experimentally observed irregular oscillations, providing a basis for a refined phase description of observed oscillatory dynamics.Comment: 4 page

The Effect of HIV/AIDS Driven Labor Organization on Agrobiodiversity: an Empirical Study in Ethiopia

Improved micronutrient intake contributes to delaying the progression of HIV into AIDS and to reducing HIV infection rates. Higher agrobiodiversity in the homegarden contributes to improving the nutritional status of farm households. Farm households with HIV/AIDS affected members observe a decrease in labor supply and productivity causing them to reallocate labor. The reallocation of labor may result in change in agrobiodiversity. Sharecropping is often used to alleviate labor shortage in agricultural production. The purpose of this paper is to analyze the implications of HIV/AIDS on agrobiodiversity through sharecropping arrangements. The study is based on a survey among 205 farm households in the Jimma zone of South Western Ethiopia. Results show that HIV/AIDS driven increase in sharecropping has a positive effect on perennial and overall agrobiodiversity in the homegarden. This offers additional intervention options to mitigate the impacts of HIV/AIDS among farm households.agrobiodiversity, Ethiopia, HIV/AIDS, labor organization, sharecropping, Farm Management, Labor and Human Capital,

Additions to Mars Global Reference Atmospheric Model (MARS-GRAM)

Three major additions or modifications were made to the Mars Global Reference Atmospheric Model (Mars-GRAM): (1) in addition to the interactive version, a new batch version is available, which uses NAMELIST input, and is completely modular, so that the main driver program can easily be replaced by any calling program, such as a trajectory simulation program; (2) both the interactive and batch versions now have an option for treating local-scale dust storm effects, rather than just the global-scale dust storms in the original Mars-GRAM; and (3) the Zurek wave perturbation model was added, to simulate the effects of tidal perturbations, in addition to the random (mountain wave) perturbation model of the original Mars-GRAM. A minor modification was also made which allows heights to go 'below' local terrain height and return 'realistic' pressure, density, and temperature, and not the surface values, as returned by the original Mars-GRAM. This feature will allow simulations of Mars rover paths which might go into local 'valley' areas which lie below the average height of the present, rather coarse-resolution, terrain height data used by Mars-GRAM. Sample input and output of both the interactive and batch versions of Mars-GRAM are presented

Research study on neutral thermodynamic atmospheric model

The Global Reference Atmospheric Model is used along with the revised perturbation statistics to evaluate and computer graph various atmospheric statistics along a space shuttle reference mission and abort trajectory. The trajectory plots are height vs. ground range, with height from ground level to 155 km and ground range along the reentry trajectory. Cross sectional plots, height vs. latitude or longitude, are also generated for 80 deg longitude, with heights from 30 km to 90 km and latitude from -90 deg to +90 deg, and for 45 deg latitude, with heights from 30 km to 90 km and longitudes from 180 deg E to 180 deg W. The variables plotted are monthly average pressure, density, temperature, wind components, and wind speed and standard deviations and 99th inter-percentile range for each of these variables