Micrometeorological measurements of sizesegregated particle number fluxes above Dutch heathlands and forests have repeatedly shown simultaneous apparent emission of particles with a diameter (Dp)<0.18μm and deposition of larger particles when measured with optical particle counters. In order to assess whether this observation may be explained by the equilibrium reaction of ammonia (NH3), nitric...

Surface concentrations and vertical fluxes of particulate organic carbon (POC) were assessed in the Amundsen Gulf (southeastern Beaufort Sea, Arctic Ocean) over the years 2004 to 2006 by using ocean color remote-sensing imagery and sequential sediment traps moored over the ca. 400m isobath. Environmental conditions (sea ice, wind) and oceanographic variables (temperature, salinity, fluorescence...

A mass balance inverse modelling procedure is applied with a time-dependent methane concentration boundary condition and a chemical transport model to relate observed changes in the surface distribution of methane mixing ratios during the 1990s to changes in its surface sources. The model reproduces essential features of the global methane cycle, such as the latitudinal distribution and seasona...

For many gasses and aerosols, dry deposition is an important sink of atmospheric mass. Dry deposition fluxes are also important sources of pollutants to terrestrial and aquatic ecosystems. The surface fluxes of some gases, such as ammonia, mercury, and certain volatile organic compounds, can be upward into the air as well as downward to the surface and therefore should be modeled as bi-directio...

A dual-source model treating the energy balance of the than measured. An empirical model was developed to reduce this bias, but it is not known how generally applicasoil/substrate and vegetation that was developed to use radiometric surface temperature observations is revised to ble it will be. Model sensitivity to typical uncertainties in remotely sensed leaf area index (LAI) and near-surface ...

11 Airborne measurements within the urban mixing layer (360 m) over Greater London are used to quantify CO2 12 emissions at the meso-scale. Daytime CO2 fluxes, calculated by the Integrative Mass Boundary Layer (IMBL) 13 method, ranged from 46 to 104 μmol CO2 m -2 s -1 for four days in October 2011. The day-to-day variability of 14 IMBL fluxes is at the same order of magnitude as for surface edd...

We found significant differences in mercury fluxes measured with a dynamic surface mercury flux chamber made of Teflon versus one made of polycarbonate. While both materials responded reasonably well when virgin materials were used, the polycarbonate chamber was found to exhibit significant chamber blanks under light after it was exposed to surface mercury fluxes of >100 ng/m2/h. Most significa...

[1] The physical and biological processes controlling surface mixed layer pCO2 and O2 were evaluated using in situ sensors mounted on a Lagrangian drifter deployed in the Atlantic sector of the Southern Ocean (∼50°S, ∼37°W) during the austral fall of 2008. The drifter was deployed three times during different phases of the study. The surface ocean pCO2 was always less than atmospheric pCO2 (−50...

Climate models predict precipitation changes for much of the humid tropics, yet few studies have investigated the potential consequences of drought on soil carbon (C) cycling in this important biome. In wet tropical forests, drought could stimulate soil respiration via overall reductions in soil anoxia, but previous research suggests that litter decomposition is positively correlated with high ...