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Wyszukujesz frazę "numerical weather prediction" wg kryterium: Temat


Wyświetlanie 1-3 z 3
Tytuł:
Experiments with three-dimensional radar reflectivity data assimilation into the COAMPS model
Autorzy:
Jakubiak, B.
Szturc, J.
Ośródka, K.
Jurczyk, A.
Powiązania:
https://bibliotekanauki.pl/articles/108601.pdf
Data publikacji:
2014
Wydawca:
Instytut Meteorologii i Gospodarki Wodnej - Państwowy Instytut Badawczy
Tematy:
weather radar
numerical weather prediction
radar reflectivity
quality control
assimilation
Opis:
High temporal and spatial resolution of radar measurements enables to continuously observe dynamically evolving meteorological phenomena. Three-dimensional (3D) weather radar reflectivity data assimilated into the numerical weather prediction model has the potential to improve initial description of the atmospheric model state. The paper is concentrated on the development of radar reflectivity assimilation technique into COAMPS mesoscale model using an Ensemble Kalman Filter (EnKF) type assimilation schemes available in Data Assimilation Research Testbed (DART) programming environment. Before weather radar data enter into the assimilation system, the measurement errors are eliminated through quality control procedures. At first artifacts associated with non-meteorological errors are removed using the algorithms based on analysis of reflectivity field pattern. Then procedures for correction of the reflectivity data are employed, especially due to radar beam blockage and attenuation in rain. Each of the correction algorithms is connected with generation of the data quality characteristic expressed quantitatively by so called quality index (QI). In order to avoid transformation of data uncertainty into assimilation scheme only the radar gates successfully verified by means of the quality algorithms were employed in the assimilation. The proposed methodology has been applied to simulate selected intense precipitation events in Poland in May and August 2010.
Źródło:
Meteorology Hydrology and Water Management. Research and Operational Applications; 2014, 2, 1; 43-54
2299-3835
2353-5652
Pojawia się w:
Meteorology Hydrology and Water Management. Research and Operational Applications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A comparison of ASCAT wind measurements and the HIRLAM model over the Baltic Sea
Autorzy:
Sluzenikina, J.
Mannik, A.
Powiązania:
https://bibliotekanauki.pl/articles/48369.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
backscattering
Baltic Sea
HIRLAM model
numerical weather prediction
ocean surface
sea surface
stormy season
wind direction
wind field
wind scatterometer
wind speed
Opis:
This paper presents a comparison of the wind data measured by the ASCAT polar-orbiting satellite scatterometer and winds forecast by the numerical weather prediction model HIRLAM in the Baltic Sea region during the stormy season in 2009. Two different resolution models were used in the comparison. Mutual quality and uncertainty characteristics of the measurements and predictions are determined. The results of the study show that the ASCAT wind data are well correlated with the HIRLAM predicted winds, which raises the credibility of both data sources in operational and hindcasting applications over the Baltic Sea. A case of phase error in a HIRLAM forecast of cyclonic activity over the Baltic Sea is discussed.
Źródło:
Oceanologia; 2011, 53, (1-TI)
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A consultative approach to charter party agreements based on virtual on time arrival
Autorzy:
Davies, H.
Bevan, S.
Powiązania:
https://bibliotekanauki.pl/articles/116955.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
economic aspects
charter party
charter party agreement
virtual nn time arrival
numerical weather prediction
Beaufort Force (BF)
Douglas Sea and Swell (DSS) scale
route optimization
Opis:
Charter Party agreements underpin the relationship between ship owners and charterers. The agreement guarantees the performance of a vessel in terms of speed and fuel consumption. On this basis the charterers plan the arrival of their cargo and their profit margin. However, ship performance is degraded by age, periods between maintenance and many vessels fail to perform as expected. Moreover the performance is only warranted during the specific conditions stated in the charter party which are not always clear. These usually refer to Beaufort Force (BF) and the Douglas Sea and Swell (DSS) scale which is archaic in the age of Numerical Weather Prediction. Given these conditions, the stage is set for conflict and there are often disputes over the weather conditions experienced. Moreover ships’ often do not arrive on time because the charterer has assumed that the ship will make good its warranted speed and not taken account of the forecast weather conditions. The authors propose a new way of approaching charter agreements with the emphasis on consultation rather than confrontation facilitated by a new web based software platform.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2017, 11, 2; 303-308
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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