Sensitivity of a climatologically-driven sea ice model to the ocean heat flux

Ocean heat flux sensitivity was studied on a numerical model of sea ice covering the Weddell Sea region of the southern ocean. The model is driven by mean monthly climatological atmospheric variables. For each model run, the ocean heat flux is uniform in both space and time. Ocean heat fluxes below 20 W m to the minus 2 power do not provide sufficient energy to allow the ice to melt to its summertime thicknesses and concentrations by the end of the 14 month simulation, whereas ocean heat fluxes of 30 W m to the minus 2 power and above result in too much ice melt, producing the almost total disappearance of ice in the Weddell Sea by the end of the 14 months. These results are dependent on the atmospheric forcing fields

2007 U.S CORN PRODUCTION RISKS: WHAT DOES HISTORY TEACH US?

Financial Economics, Production Economics, Risk and Uncertainty,

Understanding USDA Corn and Soybean Production Forecasts: Methods, Performance and Market Impacts over 1970 - 2005

The purpose of this report is to improve understanding of USDA crop forecasting methods, performance and market impact. A review of USDA’s forecasting procedures and methodology confirmed the objectivity and consistency of the forecasting process over time. Month-to-month changes in corn and soybean production forecasts from 1970 through 2005 indicated little difference in magnitude and direction of monthly changes over time. USDA production forecast errors were largest in August and smaller in subsequent forecasts. There appeared to be no trend in the size or direction of forecast errors over time. On average, USDA corn production forecasts were more accurate than private market forecasts over 1970-2005, with the exception of August forecasts since the mid-1980s. The forecasting comparisons for soybeans were somewhat sensitive to the measure of forecast accuracy considered. One measure showed that private market forecasts were more accurate than USDA forecasts for August regardless of the time period considered. Another measure showed just the opposite. As the growing season progresses the difference in the results across the two measures of forecast accuracy diminished, with USDA forecast errors in soybeans about equal to or smaller than private market errors. USDA corn production forecasts had the largest impact on corn futures prices in August and recent price reactions have been somewhat larger than historical reactions. Similar to corn, USDA soybean production forecasts had the largest impact on soybean futures prices in August with recent price reactions appearing somewhat larger than in the past. Overall, the analysis suggests that over the long-run the USDA performs reasonably well in generating crop production forecasts for corn and soybeans.Agricultural Finance,

Understanding USDA Corn and Soybean Production Forecasts: An Overview of Methods, Performance and Market Impacts

Agricultural Finance,

Advanced composite airframe program: Today's technology

The Advanced Composite Airframe Program (ACAP) was undertaken to demonstrate the advantages of the application of advanced composite materials and structural design concepts to the airframe structure on helicopters designed to stringent military requirements. The primary goals of the program were the reduction of airframe production costs and airframe weight by 17 and 22 percent respectively. The ACAP effort consisted of a preliminary design phase, detail design, and design support testing, full-scale fabrication, laboratory testing, and a ground/flight test demonstration. Since the completion of the flight test demonstration programs follow-on efforts were initiated to more fully evaluate a variety of military characteristics of the composite airframe structures developed under the original ACAP advanced development contracts. An overview of the ACAP program is provided and some of the design features, design support testing, manufacturing approaches, and the results of the flight test evaluation, as well as, an overview of Militarization Test and Evaluation efforts are described

Market Instability in a New Era of Corn, Soybean, and Wheat Prices

grain, price, increase, trend, Demand and Price Analysis, Marketing, Q11, Q13,

The Tunisian Fertilizer Distribution System - Structural and Policy Considerations

Crop Production/Industries,