Search results for "Forecast"
showing 10 items of 417 documents
Recurrent daily rainfall patterns over South Africa and associated dynamics during the core of the austral summer
2010
This paper investigates the influence of some modes of climate variability on the spatio-temporal rainfall variability over South Africa during the core of the rainy season, December to February (DJF). All analyses are based directly on the rainfall field instead of atmospheric processes and dynamics. An original agglomerative hierarchical clustering approach is used to classify daily rainfall patterns recorded at 5352 stations from DJF 1971 to DJF 1999. Five clusters are retained for analysis. Amongst them, one cluster looks most like the rainfall and circulation mean picture. Another one, representing 37% of the days, describes strong negative rainfall anomalies over South Africa resultin…
Prediction of Dry-Season Precipitation in Tropical West Africa and Its Relation to Forcing from the Extratropics
2009
Abstract Precipitation during the boreal winter dry season in tropical West Africa is rare but occasionally results in significant impacts on the local population. The dynamics and predictability of this phenomenon have been studied very little. Here, a statistical evaluation of the climatology, dynamics, and predictions of dry-season wet events is presented for the region 7.5°–15°N, 10°W–10°E. The analysis is based upon Global Precipitation Climatology Project (GPCP) merged satellite–gauge pentad rainfall estimates and 5-day 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) precipitation forecasts, and covers the 23 dry seasons (November–February) during…
Wind Speed Forecasting by Box-Jenkins Models
2008
The possibility of modelling observed wind speed time series and forecasting their future values is presented in this paper. Seasonal autoregressive integrated moving average (SARIMA) models are applied to time series formed by four years hourly average wind speed measurements in thirty sites of Sicily. Our approach is considerably different from the original one (the Box-Jenkins approach) since it is completely automatic. We use a peculiar feature of wind speed on a land area, its daily period, to identify a class of SARIMA models within which to find the best fitting model by information criteria (here we employ AICC). Here we report the results, concerning the fit and forecast accuracy, …
Applying Numerical Weather Prediction Models to the Production of New European Wind Atlas : Sensitivity studies of the wind climate to the planetary …
2018
Reliable and precise information about the wind speed climate is crucial for the development of wind energy. Meteorological processes in the mesoscale (2 – 200 km) can be represented using Numerical Weather Prediction (NWP) models such as the Weather Research and Forecast model (WRF), but before their application for creating wind energy atlases, their results and sensitivity to modelling parameters should be investigated. Here the WRF model wind speed results for the year 2015 for the Baltic Sea region are investigated, and the effect of the planetary boundary layer parametrization scheme is analyzed.
Verification of Numerical Weather Prediction Model Results for Energy Applications in Latvia
2014
Abstract Wind power forecasting greatly relies on wind speed forecasts. Numerical Weather Prediction (NWP) models are a reliable source of meteorological forecasts and they can also be used in wind resource assessment. In this work we carry out the verification of wind speed results from the NWP model Weather Research and Forecast (WRF), grid resolution - 3 km. Results from 172 model runs in May and November 2013 are compared with meteorological observations in 24 stations in Latvia. The model usually predicts wind speed values that are larger than the observed and the diurnal cycle has a large impact on verification results. Verification results obtained by interpolating model results betw…
Application of LSTM architectures for next frame forecasting in Sentinel-1 images time series
2020
L'analyse prédictive permet d'estimer les tendances des évènements futurs. De nos jours, les algorithmes Deep Learning permettent de faire de bonnes prédictions. Cependant, pour chaque type de problème donné, il est nécessaire de choisir l'architecture optimale. Dans cet article, les modèles Stack-LSTM, CNN-LSTM et ConvLSTM sont appliqués à une série temporelle d'images radar sentinel-1, le but étant de prédire la prochaine occurrence dans une séquence. Les résultats expérimentaux évalués à l'aide des indicateurs de performance tels que le RMSE et le MAE, le temps de traitement et l'index de similarité SSIM, montrent que chacune des trois architectures peut produire de bons résultats en fon…
Prévision et spatialisation des concentrations en ozone troposphérique en Bourgogne
2006
This PhD done in the Centre de Recherche de Climatologie, UMR 5210 CNRS of University of Burgundy has been supported by the Conseil Régional de Bourgogne, and the AASQA of Burgundy (Atmosf'Air). The ozone, a poison gas, is the core of this research because it is considered as one of the major worrying atmospheric pollutants in this region. We have conducted a study focused on hourly concentrations of measured ozone over several years for 12 stations. Their spatial and temporal variability are related to some features outside of the region (ground-level ozone, synoptic-scale conditions) and inside of the region (physical properties, land cover, meteorological features and precursor potential…
Étude climatique de la mousson vietnamienne et applications à la prévision saisonnière
2008
This thesis aims at documenting the physical and dynamic processes associated with the monsoon circulation of Vietnamese regional and synoptic scales, to explore the predictability of its key components and develop statistical and dynamical methods for forecasting the monsoon onset and seasonal. It is divided into two parts. The first part is, in fact, a climate study based on analysis of diagnostic data: - first, the monthly rainfall and temperature data station over the period 1960-2000 are used to analyze the cycle and the variability of these fields on the seven traditional climatic regions of Vietnam using the observed precipitation in various stations. Classifications and correlations…
THE EVOLUTION OF ADVERTISING MARKET WHERE IS ADVERTISING NOW, AND WHERE IS IT GOING?
2010
Advertising is more complicated than it used to be. In the innocent days of the 70’s and 80’s you could easily reach large audiences, both locally and nationally, through traditional advertising. Those days are long gone and an examination of the advertising playing field looks like a big pile of incomprehensible choice. In Romania, advertising has mushroomed over the past 10 years. With the emergence of large international companies and the budgets allocated to them in advertising, advertisers have appeared, only present in major cities of Romania. After 2000, there were several media institutions with very large budget and big plans for the advertising market in Romania. Are some media gr…
Forecasting Passenger Traffic for a Regional Airport
2019
Abstract The purpose of the present research is estimating the potential traffic for SIA (Sibiu International Airport, SBZ) for the year 2017. Predicting as accurate as possible the passenger traffic for a certain airport is an aspect of major importance for both the airport management and the airline companies. The theoretical quality of the forecasting models for air traffic of passengers is fundamental for obtaining the most accurate predictions. In this regard, a two-step process was used in developing the traffic forecasting model: (1) Identifying the proper regression model for traffic estimation based on the number of aircraft departures, and (2) Forecasting the number of aircraft de…