Modelling representation errors of atmospheric CO2 concentrations at a regional scale
Tolk, L.F. ; Meesters, A.G.C.A. ; Dolman, A.J. ; Peters, W. - \ 2008
Atmospheric Chemistry and Physics 8 (2008)1. - ISSN 1680-7316 - p. 6587 - 6596.
broeikasgassen - kooldioxide - klimaatverandering - modellen - emissiereductie - greenhouse gases - carbon dioxide - climatic change - models - emission reduction - mass conservation - transport models - system rams - inversion - fluxes - assimilation - variability - continent - forest
Inverse modelling of carbon sources and sinks requires an accurate quality estimate of the modelling framework to obtain a realistic estimate of the inferred fluxes and their uncertainties. So-called "representation errors" result from our inability to correctly represent point observations with simulated average values of model grid cells. They may add substantial uncertainty to the interpretation of atmospheric CO2 mixing ratio data. We simulated detailed variations in the CO2 mixing ratios with a high resolution (2 km) mesoscale model (RAMS) to estimate the representation errors introduced at larger model grid sizes of 10¿100 km. We found that meteorology is the main driver of representation errors in our study causing spatial and temporal variations in the error estimate. Within the nocturnal boundary layer, the representation errors are relatively large and mainly caused by unresolved topography at lower model resolutions. During the day, convective structures, mesoscale circulations, and surface CO2 flux variability were found to be the main sources of representation errors. Interpreting observations near a mesoscale circulation as representative for air with the correct footprint relative to the front can reduce the representation error substantially. The remaining representation error is 0.5¿1.5 ppm at 20¿100 km resolution.
|Soil tillage in the tropics and subtropics
Krause, R. ; Lorenz, F. ; Hoogmoed, W.B. - \ 1984
Eschborn : Deutsche Gesellschaft fuer Technische Zusammenarbeit - ISBN 9783880852006 - 320
klimaat - cultivators - uitrusting - erosie - gebergten - zeeklimaat - zaaibedbereiding - bodem - subtropen - grondbewerking - gereedschappen - tropen - types - continent - moesson - machines - climate - equipment - erosion - mountains - oceanic climate - seedbed preparation - soil - subtropics - tillage - tools - tropics - monsoon
Submarine fans and associated deposits in the Lower Tertiary of Guipuzcoa (Northern Spain)
Vliet, A. van - \ 1982
Landbouwhogeschool Wageningen. Promotor(en): J.D. de Jong, co-promotor(en): C.W. Drooger; P.J.C. Nagtegaal. - S.l. : S.n. - 45
reliëf - stroming - geomorfologie - geologische sedimentatie - golven - continent - tertiair - iberisch schiereiland - relief - flow - geomorphology - geological sedimentation - waves - continent - tertiary - iberian peninsula
The Lower Tertiary outcrop along the coast of Guipuzcoa, northern Spain, consists exclusively of deep-marine sediments, deposited in a narrow elongated (ESE-WNW) basin. The early Tertiary sedimentary history of this basin can be described in terms of three main phases:- a phase of predominantly (hemi-)pelagic deposition (almost the entire Paleocene);
- a phase of deposition from axially flowing carbonate-rich turbidity currents (latest Paleocene to earliest Eocene);
- a phase of lateral input of predominantly terrigenous clastics via submarine fans (largest part of the early Eocene).During the latter two phases (hemi-)pelagic sedimentation became proportionally less important -due to increasing rates of turbidite sedimentation. Late Maastrichtian to early Paleocene diapirism of Upper Triassic evaporites had created swells and depressions In the basin floor and controlled the deposition of turbidites well into the early Eocene. Various facies associations can be distinguished In the Lower Eocene turbidite successions. In the 'middle fan association' thick-bedded proximal turbidites are concentrated in overall non-channelised packages, tens of metres thick, which internally show channelling. In the 'outer fan association' thick-bedded proximal turbidites have planar geometries but are still concentrated in packages. A vertical section through these packages commonly displays a crude coarsening - and thickening - upward trend of beds. In the 'fan fringe association' thick-bedded proximal turbidites no longer occur concentrated in groups but disseminated in a matrix of thin-bedded distal turbidites. The 'basin plain association' is characterised by monotonous successions of thin-bedded turbidites. (Hemi-)Pelagic interbeds may be present in all of these facies associations. Vertical and later 1 arrangements of different facies associations can be interpreted to terms of episodes of progradation and abandonment of submarine fan systems. Long-distance lateral facies relationships could only be established with the aid of biostratigraphic control, for which use was made of calcareous nannoplankton from the interbedded hemipelagic marls. In the Lower Eocene the turbidites derived from the northern basin margin are carbonate-cemented quartz-arenites. Those derived from the southern basin margin have a lithic-arenitic composition. The stratigraphic superposition of submarine fans fed from opposite basin margins directly indicates that the deep-marine basin must have been rather narrow, probably only a few tens of kilometres wide.
|Pleistozaen - geologische Ergebnisse der Bodenkartierung in den Niederlanden
Edelman, C.H. ; Maarleveld, G.C. - \ 1958
Hannover : [s.n.] (Geologisches Jahrbuch Bd. 73)
geologische sedimentatie - kaarten - nederland - bodemkarteringen - continent - geological sedimentation - maps - netherlands - soil surveys
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