64 research outputs found
Fractional two-branes, toric orbifolds and the quantum McKay correspondence
We systematically study and obtain the large-volume analogues of fractional
two-branes on resolutions of orbifolds C^3/Z_n. We study a generalisation of
the McKay correspondence proposed in hep-th/0504164 called the quantum McKay
correspondence by constructing duals to the fractional two-branes. Details are
explicitly worked out for two examples -- the crepant resolutions of C^3/Z_3
and C^3/Z_5.Comment: 34 pages, 2 figures, LaTeX (JHEP3 style); (v2) typos corrected; (v3)
sec 3 reorganise
Application of the CALIOP layer product to evaluate the vertical distribution of aerosols estimated by global models: AeroCom phase I results
The CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) Layer data are used to evaluate
the vertical distribution of aerosols in 12 global models from AeroCom (Aerosol Comparisons
between Observations and Models) simulations prepared for the 4th IPCC assessment report.
Annual and seasonal extinction profiles are analysed over 13 sub-continental regions
representative of industrial, dust, and biomass burning pollution, from CALIOP (2007-2009)
observations and AeroCom (2000) simulations. An extinction mean height diagnostic (Zα) is also
calculated over the 0-10 km altitude range to quantitatively assess the models performance. The
mean extinction profiles derived from CALIOP layer products provide a robust climatology of the
aerosol vertical distribution over large regions and for the seasonal time scale. The mean
extinction decreases from the surface to about 6 km and shows consistent regional specificities
and low inter-annual variability. While most models are significantly correlated with the
observation in terms of Zα, some do better than others and 2 of the 12 models perform particularly
well in all seasons. In most regions, notably over the maritime regions, downwind of the
continents, most models show higher Zα than observed by CALIOP, whereas over the African and
Chinese dust source regions, Zα is underestimated during northern hemisphere spring and summer.
The positive model bias in Zα is in mainly due to an overestimate of the extinction above 6 km.
Potential factors related to models and observations that contribute to the differences are
discussed.JRC.H.2-Air and Climat
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