Results of the meteorological model WRF-ARW over Catalonia, using different parameterizations of convection and cloud microphysics

The meteorological model WRF-ARW (Weather Research and Forecasting - Advanced ResearchWRF) is a new generation model that has a worldwide growing community of users. In theframework of a project that studies the feasibility of implementing it operationally at the Mete-orological Service of Catalonia, a verification of the forecasts produced by the model in severalcases of precipitation observed over Catalonia has been carried out. Indeed, given the impor-tance of precipitation forecasts in this area, one of the main objectives was to study the sensitivityof the model in different configurations of its parameterizations of convection and cloud micro-physics. In this paper, we present the results of this verification for two domains, a 36-km gridsize and one of 12 km grid size, unidirectionally nested to the previous one. In the externaldomain, the evaluation was based on the analysis of the main statistical parameters (ME andRMSE) for temperature, relative humidity, geopotential and wind, and it has been determinedthat the combination using the Kain-Fritsch convective scheme with the WSM5 microphysicalscheme has provided the best results. Then, with this configuration set for the external domain,some forecasts at the nested domain have been done, by combining different convection andcloud microphysics schemes, leading to the conclusion that the most accurate configuration isthe one combining the convective parameterization of Kain-Fritsch and the Thompson micro-physics scheme

Sensitivity of the WRF forecasts to the cumulus convection and cloud microphysics parameterizations

Màster Oficial en Meteorologia, curs 2006-2007En aquest estudi s'avalua la sensibilitat dels pronòstics del model de mesoescala WRF (Weather Research and Forecasting) a diferents combinacions de parametritzacions de la convecció (concretament Kain-Fritsch, Betts-Miller-Janjic i Grell-Devenyi) i de la microfísica de núvols (WSM5 i Thompson), amb l'objectiu de determinar quina configuració proporciona els millors resultats per a la implementació operativa del model. Per portar a terme l'avaluació, s'han seleccionat una sèrie d'episodis amb precipitació sobre Catalunya, i s'ha realitzat una verificació contrastada dels camps analitzat i pronosticat de la temperatura, altura geopotencial, humitat relativa i vent. Les simulacions s'han efectuat sobre un domini de 36 km de pas de malla, centrat a la Península Ibèrica. Els resultats mostren que els pronòstics són més sensibles a l'esquema convectiu que al microfísic, i que la configuració amb la parametrització de la convecció de Kain-Fritsch i la microfísica WSM5 proporciona els resultats més satisfactoris.This work evaluates the sensitivity of the forecasts by the WRF (Weather Research and Forecasting) mesoscale model to various combinations of its convective parameterizations (Kain-Fritsch, Betts-Miller-Janjic and Grell-Devenyi) and two microphysical schemes (WSM5 and Thompson), in order to determine the configuration that better fullfills the requirements for an operational implementation of the model. Several events with precipitation over Catalonia (NE Spain) have been selected to carry out a contrasted verification of the forecasted and analyzed fields of temperature, geopotential height, relative humidity and wind. The simulations have been run over a 36-km grid, centered at the Iberian Peninsula. The results show that forecasts are more sensitive to convective than microphysical schemes and that the configuration with the Kain-Fritsch convection scheme and the WSM5 microphysics parameterization produces the best results.Servei Meteorològic de Cataluny

Elimination profile of triamcinolone hexacetonide and its metabolites in human urine and plasma after a single intra-articular administration

Triamcinolone hexacetonide (THA) is a synthetic glucocorticoid (GC) used by intra-articular (IA) administration. GCs are prohibited in sports competitions by systemic routes, and they are allowed by other routes considered of local action (IA administration, among others). The aim of the present work was to study the metabolic profile of THA in urine and plasma following IA administration. Eight patients (4 males and 4 females) with knee osteoarthritis received an IA dose of THA (40 mg) in the knee joint. Spot urine and plasma samples were collected before injection and at different time periods up to day 23 and 10 post-administration, respectively. The samples were analysed by liquid chromatography-tandem mass spectrometry. Neither THA nor specific THA metabolites were detected in urine. Triamcinolone acetonide (TA) and 6β-hydroxy-triamcinolone acetonide were the main urinary metabolites. Maximum concentrations wereobtained between 24 and 48 h after administration. Using the reporting level of 30 ng/mL to distinguish allowed from forbidden administrations of GCs, a large number of false adverse analytical findings would be reported up to day 4. On the other hand, TA was detected in all plasma samples collected up to day 10 after administration. THA was also detected in plasma but at lower concentrations. The detection of plasma THA would be an unequivocal proof to demonstrate IA use of THA. A reversible decrease was observed in plasma concentrations of cortisol in some of the patients, indicating a systemic effect of the drug