This collection of data was used in the preparation of a study on abandoned cropland in the United States. Abandoned cropland (ACL) is often cited as a land resource upon which to produce energy crops while reducing the negative impacts of broad scale energy crop production; for example, carbon emissions from land-cover change and competition with food production. In contrast to marginal land which refers to a set of biophysical and economic criteria usually imposed...

During Snowball Earth episodes of the Neoproterozoic and Paleoproterozoic, limited amounts of tropical open ocean (Jormungand), or tropical ocean with thin ice cover, would help to explain (1) vigorous glacial activity in low latitudes, (2) survival of photosynthetic life, and (3) deglacial recovery without excessive buildup of atmospheric CO2. Some previous models have suggested that tropical open ocean or thin-ice cover is possible; however its viability in the presence of kilometer-thick sea glaciers flowing from...

uture liquid fuel demand from renewable sources may, in part, be met by converting the seasonally wet portions of the landscape currently managed for soil and water conservation to perennial energy crops. However, this shift may increase nitrous oxide (N2O) emissions, thus limiting the carbon (C) benefits of energy crops. Particularly high emissions may occur during the transition period when the soil is disturbed, plants are establishing, and nitrate and water accumulation may favor emissions....

Co-seismic luminescence, commonly referred to as Earthquake lights (EQLs), is an atmospheric luminous phenomenon occurring before and during strong earthquakes. We utilize the assumption that strong currents are produced inside the Earth during earthquakes and model the current and field distribution inside and above the Earth to find the conditions where electrical discharges can appear. The simulation results quantify the effects of source currents for various configurations of current dipoles inside the Earth. The results...