Search results for "Orography"
showing 10 items of 26 documents
A pragmatic approach for downscaling precipitation in alpine-scale complex terrain
2006
A statistical method is presented to downscale precipitation from a mesoscale atmospheric model simulation. The algorithm consists of two steps. First, local subscale variability is estimated based on a high resolution observed climatology. Second, there is a bias correction, which constrains the downscaled model climatology to be equal to the observed climatology on the coarse grid. Combining both steps results in a local scaling factor for each day of the climatological year. The method is applied to the upper Danube catchment which encompasses part of the European Alps and which is characterized by highly complex orography. The subgrid-scale variability described by the first part of the…
Dynamics and Predictability of a Heavy Dry-Season Precipitation Event over West Africa—Sensitivity Experiments with a Global Model
2009
Abstract In January 2002 the Cape Verde region in tropical West Africa was hit by an exceptionally heavy precipitation event. Rain rates of up to 116 mm (48 h)−1 caused harmful impacts on the local population. The rainfall was triggered by a series of two upper-level disturbances penetrating from the extratropics to the West African coast. This study investigates the dynamics and predictability of this event on the basis of simulations with the global model Global Model Europe (GME) of the German Weather Service [i.e., Deutscher Wetterdienst (DWD)] initialized by the European Centre for Medium-Range Weather Forecasts (ECMWF) analysis data. Free forecasts satisfactorily reproduce the upper-l…
Initiation of deep convection at marginal instability in an ensemble of mesoscale models: a case-study from COPS
2011
The present study investigates the initiation of precipitating deep convection in an ensemble of convection-resolving mesoscale models. Results of eight different model runs from five non-hydrostatic models are compared for a case of the Convective and Orographically-induced Precipitation Study (COPS). An isolated convective cell initiated east of the Black Forest crest in southwest Germany, although convective available potential energy was only moderate and convective inhibition was high. Measurements revealed that, due to the absence of synoptic forcing, convection was initiated by local processes related to the orography. In particular, the lifting by low-level convergence in the planet…
A simple method to directly retrieve reference evapotranspiration from geostationary satellite images
2013
Abstract Application of FAO-56 methodology for the assessment of reference evapotranspiration, ET 0 , is challenging in areas of the world with sparse meteorological network stations. For this reason alternative procedures using remotely observed data have been proposed in the literature. In this work, a simplified version of the Makkink approach [J. Inst. Wat. Eng. 11: 277–288, 1957] was tested in a typical Mediterranean environment (Sicily, Italy). The implemented Makkink approach (MAK) uses remotely estimated solar radiation derived from Meteosat Second Generation (MSG) satellite data and in situ observations of air temperature to assess ET 0 at daily time scale. Alternatively, taking ad…
New insights into the daily and symbolic use of plants during initial occupations of Formentera (Balearic Islands, Spain)
2021
The island of Formentera, with its small extension and flat orography, was settled relatively late in Mediterranean prehistory between the third and second millennium BC. The sites presented in thi...
Isotopic composition of the precipitations in the central Mediterranean: Origin marks and orographic precipitation effects
2006
The isotopic composition of the rainfall in northwestern Sicily (Italy, central Mediterranean) was investigated in the period February 2002 to March 2003. A rain gauge network was installed and sampled monthly. The monthly values of the D and 18O ratios showed a wide range that reflected seasonal climatic variations. Mean weighted values were used to define an isotopic model of precipitation. Temporal variations in deuterium excess were also investigated. Using mean volume weighted values, the Local Meteoric Water Line (LMWL) can be represented by the equation: δD = 4.7δ18O - 8.2 (r2 = 0.96). Deuterium excess (d = δD - 8δ18O) was found to be strongly related to orography. The coastline samp…
Impact of Initial Soil Temperature Derived from Remote Sensing and Numerical Weather Prediction Datasets on the Simulation of Extreme Heat Events
2016
Extreme heat weather events have received increasing attention and has become of special importance as they can remarkably affect sectors as diverse as public health, energy consumption, water resources, natural biodiversity and agricultural production. In this regard, summer temperatures have become a parameter of essential interest under a framework of a hypothetical increase in the number of intense-heat conditions. Thus, their forecast is a crucial aspect bearing in mind a mitigation of the effects and impacts that these intense-heat situations could produce. The current work tries to reach a better understanding of these sorts of situations that are really common over the Western Medit…
Palermo vs Panormus
2019
Quando nel settimo secolo a.C. i coloni fenici arrivarono dal mare nel Golfo di Palermo (anticipato, a grande distanza, dalla peculiare forma del Monte Pellegrino), certamente capirono come la valle che si apriva davanti a loro (la cosiddetto Conca d'oro) - ricca di vegetazione, attraversata da corsi d’acqua e protetta dal micidiale vento di Nord / Ovest, il Maestrale - fosse il posto giusto per fondare una nuova città. Le generazioni seguenti continuarono a costruire la città sul promontorio, mantenendo e consolidando l'orientamento Est / Ovest e affidando all'asse principale (il Cassaro) il ruolo, non secondario e fortemente simbolico, di collegare le montagne e il mare attraverso la citt…
The Mode of Calcification in Atherosclerotic Lesions
1977
Calcific deposits in atherosclerotic plaques are usually considered to be an end stage of advanced atheroma formation. Postmortem studies of coronary arteries showed that pronounced atherosclerotic calcifications are strongly associated with stenosis of the involved segments and ischemic myocardial lesions (Eggen et al. 1965; McCarthy and Palmer 1974). A close correlation has also been found between calcific lesions detected by fluoroscopy or cinefluorography and clinical coronary artery disease (Oliver et al. 1964; Wartburton et al. 1968). Therefore, arterial calcification detected during life may be of important prognostic significance. Moreover, larger calcific plaques may influence the …
Role of videofluorography with water siphon test in otolaryngologic presentations of GERD
2004
In recent years digital videofluorography (VFG) with water siphon test (WST) has been proposed just for diagnosing hiatal hernia and/or gastroesophageal reflux. PATIENTS AND METHODS: Fifteen patients undergone Laparoscopic Nissen (LN) for complicated GERD associated to hiatal hernia, were referred for VFG and WST in order to evaluate the functional results of surgery. At one-month videofluorographic control thirteen patients had just a minimal prolonged esophageal transit time but only six of these had an early postoperative dysphagia, whereas at six months control the prolonged esophageal transit time was present in three patients two of which complained a very light dysphagia. One patient…