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In order to obtain viscosities of biodiesel fuels at a temperature range from 0 to 100°C in the steps of 10°C, DV-II+ Pro rotary viscosimeter from Brookfield Engineering Co., USA, was used and tests were performed at 20°C ambient temperature. The viscosity measurements were made on a viscosimeter at a 100 rpm constant speed with PC control. The data with the Wingather VII software from Brookfield Engineering Co., USA, were recorded in the computer at 5 second intervals. It is observed that biodiesels are similar to diesel fuels in view of the viscosity properties when the diesel fuel concentration in which biodiesel and the temperature is increased. [ABSTRACT FROM AUTHOR]

In order to test the sensitivity of regional climate to regional-scale atmosphere-land cover feedbacks, we have employed a regional climate model asynchronously coupled to an equilibrium vegetation model, focusing on the western United States as a case study. CO2-induced atmosphere-land cover feedbacks resulted in statistically significant seasonal temperature changes of up to 3.5°C, with land cover change accounting for up to 60% of the total seasonal response to elevated atmospheric CO2 levels. In many areas, such as the Great Basin, albedo acted as the primary control on changes in surface temperature. Along the central coast of California, soil moisture effects magnified the temperature response in JJA and SON, with negative surface soil moisture anomalies accompanied by negative evaporation anomalies, decreasing latent heat flux and further increasing surface temperature. Additionally, negative temperature anomalies were calculated at high elevation in California and Oregon in DJF, MAM and SON, indicating that future warming of these sensitive areas could be mitigated by changes in vegetation distribution and an associated muting of winter snow-temperature feedbacks. Precipitation anomalies were almost universally not statistically significant, and very little change in mean seasonal atmospheric circulation occurred in response to atmosphere-land cover feedbacks. Further, the mean regional temperature sensitivity to regional-scale land cover feedbacks did not exceed the large-scale sensitivity calculated elsewhere, indicating that spatial heterogeneity does not introduce non-linearities in the response of regional climate to CO2-induced atmosphere-land cover feedbacks. [ABSTRACT FROM AUTHOR]

The article reports on the strange observations of the El Reno, Oklahoma, Mesonet (ELRE) site. Inversions of 10 degrees Celsius or greater between 1.5 and 9 meters above the ground are measured at the Menoset site. Inversions at ELRE occur due to rapid cooling near the surface shortly after sunset when conditions are calm, clear, and dry. The air temperature at ELRE can be significantly cooler than other surrounding Mesonet sites. The standard siting requirements established by the World Meteorological Organization.

This article comments on temperature trend results, referred to as MAPP, that estimate surface temperature trends over the U.S. due to aircraft-induced contrails and cirrus, to be in good agreement with corresponding observations over the period 1973 to 1994. MAPP reach this conclusion based on a simple model calibrated using general circulation model results. Depending on the assumed cirrus optical depth, MAPP estimate an annual-mean surface warming trend over the U.S. However, the author believes that MAPP significantly overestimate the climate impact of aircraft-induced clouds.