[1] A multiple‐box model was developed to determine how meteorological, anthropogenic, and biological processes combine to produce diel cycles of carbon dioxide (CO2) mole fraction during each of the four calendar‐based seasons within Salt Lake Valley, Utah, USA. The model was forced by observed winds, sounding‐derived mixing depths, an anthropogenic CO2 emissions inventory, and net biological ...

Direct quantification of fossil fuel CO2 (CO2ff) in atmospheric samples can be used to examine several carbon cycle and air quality questions. We collected in situ CO2, CO, and CH4 measurements and flask samples in the boundary layer and free troposphere over Sacramento, California, USA, during two aircraft flights over and downwind of this urban area during spring of 2009. The flask samples we...

Observations of atmospheric CO2 mole fraction and the 13C / 12C ratio (expressed as δ13C) in urban airsheds provide constraints on the roles of anthropogenic and natural sources and sinks in local and regional carbon cycles. In this study, we report observations of these quantities in Nanjing at hourly intervals from March 2013 to August 2015, using a laser-based optical instrument. Nanjing is ...

The United States currently meets 80% of its energy needs by burning fossil fuels to form CO2. The combustion-based production of CO2 has evolved into a major environmental challenge that extends beyond national borders and the issue has become as politically charged as it is technologically demanding. Whereas CO2 levels in the atmosphere had remained stable over the 10,000 years preceeding the...

Coal combustion by-products such as fly ash (FA), brine and CO2 from coal fired power plants have the potential to impact negatively on the environment. Reaction of CO2 with FA/ brine slurry can potentially provide a viable route for CO2 sequestration through formation of mineral carbonates. Fractionated FA has varying amounts of CaO which not only increases the brine pH but can also be convert...

[1] This study evaluates the potential impact of clouds on ecosystem CO2 and CO2 isotope fluxes (‘‘isofluxes’’) in two contrasting ecosystems (a broadleaf deciduous forest and a C4 grassland) in a region for which cloud cover, meteorological, and isotope data are available for driving the isotope-enabled land surface model (ISOLSM). Our model results indicate a large impact of clouds on ecosyst...

more, different ecosystems are limited or controlled by a variety of factors, so that understanding why certain Soil is a potential C sink and could offset rising atmospheric CO2. ecosystems respond and others do not will become imThe capacity of soils to store and sequester C will depend on the rate of C inputs from plant productivity relative to C exports controlled portant for understanding ...

Net primary productivity (NPP) is enhanced under future atmospheric [CO2] in temperate forests representing a broad range of productivity. Yet questions remain in regard to how elevated [CO2]-induced NPP enhancement may be affected by climatic variations and limiting nutrient resources, as well as how this additional production is distributed among carbon (C) pools of different longevities. Usi...

11 New Zealand’s largest industrial sector is pastoral agriculture, giving rise to a large fraction of 12 the country’s emissions of methane (CH4) and nitrous oxide (N2O). We designed a system to 13 continuously measure CH4 and N2O fluxes at the field scale on two adjacent pastures that 14 differed with respect to management. At the core of this system was a closed-cell Fourier15 transform infr...