Arnaud Mortier
Institut de Mathématiques de Toulouse
15 Papers
57 Citations
Arnaud Mortier is an academic researcher from Institut de Mathématiques de Toulouse. The author has contributed to research in topics: Knot (unit) & Cohomology. The author has an hindex of 5, co-authored 14 publications. Previous affiliations of Arnaud Mortier include Osaka City University & Institut de Mathématiques de Jussieu.
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Papers
The MACC-II 2007–2008 reanalysis: atmospheric dust evaluation and characterization over northern Africa and the Middle East [Discussion paper]
Emilio Cuevas Agulló,C. Camino,Angela Benedetti,Sara Basart,Enric Terradellas,José María Baldasano,J.-J. Morcrette,Béatrice Marticorena,Philippe Goloub,Arnaud Mortier,Alberto Berjón,C. Pérez,Manuel Gil-Ojeda,Michael Schulz +13 more
- 01 Jan 2014
Abstract: Abstract. In the present work, atmospheric mineral dust from a MACC-II short reanalysis run for 2 years (2007–2008) has been evaluated over northern Africa and the Middle East using satellite aerosol products (from MISR, MODIS and OMI satellite sensors), ground-based AERONET data, in situ PM10 concentrations from AMMA, and extinction vertical profiles from two ground-based lidars and CALIOP satellite-based lidar. The MACC-II aerosol optical depth (AOD) spatial and temporal (seasonal and interannual) variability shows good agreement with those provided by satellite sensors. The capability of the model to reproduce the AOD, Angstrom exponent (AE) and dust optical depth (DOD) from daily to seasonal time-scale is quantified over 26 AERONET stations located in eight geographically distinct regions by using statistical parameters. Overall DOD seasonal variation is fairly well simulated by MACC-II in all regions, although the correlation is significantly higher in dust transport regions than in dust source regions. The ability of MACC-II in reproducing dust vertical profiles has been assessed by comparing seasonal averaged extinction vertical profiles simulated by MACC-II under dust conditions with corresponding extinction profiles obtained with lidar instruments at M'Bour and Santa Cruz de Tenerife, and with CALIOP. We find a good agreement in dust layers structures and averaged extinction vertical profiles between MACC-II, the lidars and CALIOP above the marine boundary layer from 1 to 6 km. Surface dust daily mean concentrations from MACC-II reanalysis has been evaluated with daily averaged PM10 at three monitoring stations of the Sahelian Dust Transect. MACC-II correctly reproduces daily to interannual surface dust concentration variability, although it underestimates daily and monthly means all year long, especially in winter and early spring (dry season). MACC-II reproduces well the dust variability recorded along the station transect which reflects the variability in dust emission by different Saharan sources, but fails in reproducing the sporadic and very strong dust events associated to mesoscale convective systems during the wet season.
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Polyak type equations for virtual arrow diagram invariants in the annulus
TL;DR: In this paper, the authors describe the space of arrow diagram formulas for virtual knot diagrams in the annulus ℝ × 𝕊1 as the kernel of a linear map, inspired from a conjecture due to Polyak.
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Gauss diagrams of real and virtual knots in the solid torus
TL;DR: A new kind of Gauss diagrams is defined to describe knots in the solid torus with projections in the annulus that provide an efficient tool for showing that a knot diagram can be fully recovered from its decorated Gauss diagram.
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Virtual knot theory on a group
TL;DR: In this paper, the authors associate a Gauss diagram theory with a group endowed with a Z/2-valued morphism, and show that for a particular choice of the group these diagrams encode faithfully virtual knots on a given arbitrary surface.
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Combinatorial cohomology of the space of long knots
TL;DR: In this paper, the authors define a combinatorial graded cochain complex such that the elements of an explicit submodule in the cohomology define algebraic intersections with some geometrically simple strata in the space of knots.