Efficient determination of vehicle emission factors by fuel use category using on-road measurements: downward trends on Los Angeles freight corridor I-710 Atmospheric Chemistry and Physics DOI 10.5194/acp-13-347-2013 11 January 2013 We developed an alternative method that links real-time on-road pollutant measurements from a mobile platform with real-time traffic data, and allows efficient calculation of both the average and the spread of vehicle emission factors for light-duty gasoline-powered vehicles and heavy-duty diesel-powered vehicles. Read more
Time scale of the largest imaginable magnetic storm Nonlinear Processes in Geophysics DOI 10.5194/npg-20-19-2013 8 January 2013 The depression of the horizontal magnetic field at Earth’s equator for the largest imaginable magnetic storm has been estimated (Vasyliūnas, 2011a) as −Dst ~ 2500 nT. The obvious related question, analysed in this paper, is how long it would take the solar wind to supply the energy content of this largest storm. Read more
Tide-surge interaction in the English Channel Natural Hazards and Earth System Sciences DOI 10.5194/nhess-12-3709-2012 19 December 2012 The English Channel is characterised by strong tidal currents and a wide tidal range, such that their influence on surges is expected to be non-negligible. In order to better assess storm surges in this zone, tide-surge interactions are investigated. Read more
Management, regulation and environmental impacts of nitrogen fertilization in northwestern Europe under the Nitrates Directive; a benchmark study Biogeosciences DOI 10.5194/bg-9-5143-2012 14 December 2012 Implementation of the Nitrates Directive (NiD) and its environmental impacts were compared for member states in the northwest of the European Union (Ireland, United Kingdom, Denmark, the Netherlands, Belgium, Northern France and Germany). The main sources of data were national reports for the third reporting period for the NiD (2004–2007) and results of the MITERRA-EUROPE model. Read more
Stratospheric winds, transport barriers and the 2011 Arctic ozone hole Nonlinear Processes in Geophysics DOI 10.5194/npg-19-687-2012 12 December 2012 We consider the issue of what constitutes suitable environmental conditions for the formation and maintenance of a polar ozone hole. Our discussion focuses on the importance of the stratospheric wind field and, in particular, the importance of a high latitude zonal jet, which serves as a meridional transport barrier both prior to ozone hole formation and during the ozone hole maintenance phase. Read more
The stability of grounding lines on retrograde slopes The Cryosphere DOI 10.5194/tc-6-1497-2012 12 December 2012 The stability of marine ice sheets grounded on beds that slope upwards in the overall direction of flow is investigated numerically in two horizontal dimensions. We give examples of stable grounding lines on such retrograde slopes illustrating that marine ice sheets are not unconditionally unstable in two horizontal dimensions. Read more
Internal respiration of Amazon tree stems greatly exceeds external CO2 efflux Biogeosciences DOI 10.5194/bg-9-4979-2012 6 December 2012 Here, we studied gas exchange from stems of tropical forest trees using a new approach to better understand respiration in an ecosystem that plays a key role in the global carbon cycle. Read more
The link between great earthquakes and the subduction of oceanic fracture zones Solid Earth DOI 10.5194/se-3-447-2012 5 December 2012 We construct a model for the geometry of subduction coupling zones and combine it with global geophysical data sets to demonstrate that the occurrence of great (magnitude ≥ 8) subduction earthquakes is strongly biased towards regions associated with intersections of oceanic fracture zones and subduction zones. Read more
No statistically significant effect of a short-term decrease in the nucleation rate on atmospheric aerosols Atmospheric Chemistry and Physics DOI 10.5194/acp-12-11573-2012 4 December 2012 We use a global aerosol microphysics model to determine whether a 10 day reduction of 15% in the nucleation rate could generate a statistically significant response in aerosol concentrations and optical properties. Read more
Ocean acidification limits temperature-induced poleward expansion of coral habitats around Japan Biogeosciences DOI 10.5194/bg-9-4955-2012 4 December 2012 Using results from four coupled global carbon cycle-climate models combined with in situ observations, we estimate the effects of future global warming and ocean acidification on potential habitats for tropical/subtropical and temperate coral communities in the seas around Japan. Read more