[1] Natural emissions of nonmethane volatile organic compounds (NMVOCs) play a crucial role in the oxidation capacity of the lower atmosphere and changes in concentrations of major greenhouse gases (GHGs), particularly methane and tropospheric ozone. In this study, we integrate a global biogenic model within a terrestrial ecosystem model to investigate the vegetation and soil emissions of key i...

Climate on Earth strongly depends on the radiative balance of its atmosphere, and thus, on the abundance of the radiatively active greenhouse gases. Largely due to human activities since the Industrial Revolution, the atmospheric burden of many greenhouse gases has increased dramatically. Direct measurements during the last decades and analysis of ancient air trapped in ice from polar regions a...

As part of its strategic plan, the National Aeronautics and Space Administration (NASA) formulated the goal of “utilizing the knowledge of the Sun, Earth and other planetary bodies to develop predictive environmental, climate, and natural resource models to help ensure sustainable development, and improve the quality of life on Earth” (NASA 1998). We know now that, over geologic periods, the ea...

The magnetites and sulfides located in the rims of carbonate globules in the Martian meteorite ALH84001 have been claimed as evidence of past life on Mars. Here, we consider the possibility that the rims were formed by dissolution and reprecipitation of the primary carbonate by the action of water. To estimate the rate of these solution-precipitation reactions a kinetic model of magnesite-sider...

Knowledge of the refractivity index in the lower atmosphere is very important in the design, transmission and performance analysis of line-of-sight (LOS) terrestrial links. In oceanic environments, radio wave propagation is affected by the high variability with space and time of the meteorological parameters. Radiosonde data have been used in the analysis of the effect of climatic conditions in...

A ~ 62 My periodicity in fossil biodiversity has been observed in independent studies of paleontology databases over ~0.5Gy. The period and phase of this biodiversity cycle coincides with the oscillation of our solar system normal to the galactic disk with an amplitude ~70 parsecs and a period ~64 My. Our Galaxy is falling toward the Virgo cluster, forming a galactic shock at the north end of o...

In recent years, methane (CH4) has received increasing scientific attention because it is the most abundant non-CO2 atmospheric greenhouse gas (GHG) and controls numerous chemical reactions in the troposphere and stratosphere. However, there is much that is unknown about CH4 sources and sinks and their evolution over time. Here we show that near-surface cavities in the uppermost vadose zone are...

the orderly arrangement of air densities and pressures demanded by gravity. The latter, on the other hand, as perpetually and continuously sets portions of the air in motion, in order to establish and maintain a state of equilibrium, which, however, is never attained. We must clearly recognize that the ceaseless complex changes in and motions of our atmosphere represent in fact the only state o...

A review of conceptual models that scientists use to characterize the nitrogen (N) cycle and to conduct N mass balance studies at global, regional and local scales is presented. Large uncertainties in processes and process rates make it difficult to conduct precise N mass balances and the dominant conceptual model has changed in recent decades. An earlier conceptual model recognized explicitly ...

Although the planets Mercury, Venus, Earth, and Mars have masses within a single order of magnitude range, they possess atmospheres with extremely different properties (Table 1). These bodies may have initially possessed primordial atmospheres of solar composition whose dominant light gases (hydrogen and helium) were lost to space and replaced by outgassed water, carbon dioxide, and nitrogen (a...