Global Assessment of the SMAP Level-4 Surface and Root-Zone Soil Moisture Product Using Assimilation Diagnostics.

The Soil Moisture Active Passive (SMAP) mission Level-4 Soil Moisture (L4_SM) product provides 3-hourly, 9-km resolution, global estimates of surface (0-5 cm) and root-zone (0-100 cm) soil moisture and related land surface variables from 31 March 2015 to present with ~2.5day latency. The ensemble-based L4_SM algorithm assimilates SMAP brightness temperature (Tb) observations into the Catchment land surface model.

Molecular dynamic simulation of dicarboxylic acid coated aqueous aerosol: structure and processing of water vapor.

Organic monolayers at the surfaces of aqueous aerosols play an important role in determining the mass, heat transfer rate and surface reactivity of atmospheric aerosols. They can potentially contribute to the formation of cloud condensation nuclei (CCN) and are involved in a series of chemical reactions occurring in atmosphere. Recent studies even suggest that organic-coated interfaces could have played some role in prebiotic biochemistry and the origin of life.

Sticking coefficient and processing of water vapor on organic-coated nanoaerosols.

Organic-based aerosols may play an unexpectedly important role in the atmospheric processing of water vapor. In this paper, we report results of a molecular dynamics (MD) study on the sticking coefficient of water vapor on a coated particle (water droplet coated with fatty acid of radius approximately 4 nm). The sticking coefficient was found to be almost a constant (11-16%) for incident speeds around the most probable speed as opposed to 100% for water vapor incident on a pure water droplet.

"Effective" negative surface tension: a property of coated nanoaerosols relevant to the atmosphere.

Atmospheric aerosols play a very important role in atmospheric processes and have a major influence on the global climate. In this paper, we report results of a molecular dynamics study on the unique properties of organic-coated water droplets. In particular, we find that, for particles preferring an inverted micelle structure, the lower chain-chain interaction, with increasing radial distance from the water-organic interface, results in a negative internal radial pressure profile for the organic layer.