We measured the flux of CO2 across the air–water interface using the floating chamber method in three European estuaries with contrasting physical characteristics (Randers Fjord, Scheldt, and Thames). We computed the gas transfer velocity of CO2 (k) from the CO2 flux and concomitant measurements of the air–water gradient of the partial pressure of CO2 (pCO2). There was a significant linear rela...

Results from a 28-year simulation (1979– 2006) over the Greenland ice sheet (GrIS) reveal an increase of solid precipitation (+0.4±2.5 km3 yr−2) and runoff (+7.9±3.3 km3 yr−2) of surface meltwater. The net effect of these competing factors is a significant Surface Mass Balance (SMB) loss of −7.2±5.1 km3 yr−2. The contribution of changes in the net water vapour flux (+0.02±0.09 km3 yr−2) and rai...

Developing oilseeds synthesize large quantities of triacylglycerol from sucrose and hexose. To understand the fluxes involved in this conversion, a quantitative metabolic flux model was developed and tested for the reaction network of glycolysis and the oxidative pentose phosphate pathway (OPPP). Developing Brassica napus embryos were cultured with [U-13C6]glucose, [1-13C]glucose, [6-13C]glucos...

We measured the flux of CO2 across the air–water interface using the floating chamber method in three European estuaries with contrasting physical characteristics (Randers Fjord, Scheldt, and Thames). We computed the gas transfer velocity of CO2 (k) from the CO2 flux and concomitant measurements of the air–water gradient of the partial pressure of CO2 (pCO2). There was a significant linear rela...

The energy balance equation of an atmospheric column indicates that two approaches are possible to compute regional net surface flux. first approach is use the sum flux components F net,c and second top-of-atmosphere (TOA) irradiance horizontal transport by atmosphere net,t . When averaged over global ocean, are, respectively, 16 2 Wm –2 , both larger than ocean heating rate derived from temper...

Simulations of above-canopy water vapor and CO2 fluxes were calculated by the USGF linked model of canopy gas exchange and subsurface processes for the 1996-1997 winter wheat season at the AmeriFlux Wheat Site, Oklahoma. Soil surface CO2 flux plus canopy gas exchange and transpiration plus soil evaporation modeled the CO2 and water vapor fluxes, respectively. Parameter values for net photosynth...

Measuring and modeling carbon (C) stock changes in terrestrial ecosystems are pivotal in addressing global C-cycling model uncertainties. Difficulties in detecting small short-term changes in relatively large C stocks require the development of robust sensitive flux measurement techniques. Net ecosystem exchange (NEE) ground-level chambers are increasingly used to assess C dynamics in low veget...

13C- and31P-NMR were used in methylene blue-treated human erythrocytes to determine the dependence on intracellular Mg2+ concentration ([Mg2+]i) of the pentose phosphate pathway (PPP), the glycolytic pathway, and adenine nucleotide synthesis. The PPP flux had an [Mg2+]iat half-maximal velocity ([Mg2+]i,0.5) of 0.02 mM, well below the physiological range (0.2-0.7 mM). Flux through the PPP was re...

The urinary bladder of Amphiuma exhibits stable transport properties and an electrical potential difference in vitro. The lumen is significantly negative to the serosa and under short-circuited conditions flux rations for Na and Cl of 5.92 +/- 0.42 and 1.81 +/- 0.20, respectively, were observed. The close agreement between the short-circuit current and net Na flux suggests that most, if not all...

Because of the scarcity of observational data, existing estimates of the heat and water budgets of the Persian Gulf are rather uncertain. This uncertainty leaves open the fundamental question ofwhether this water body is a net heat source or a net heat sink to the atmosphere. Previous regional modeling studies either used specified surface fluxes to simulate the hydrodynamics of the Gulf or pre...