Results 41 to 50 of about 6,317 (256)

Polar‐low track prediction using machine‐learning methods

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Machine‐learning models are developed to produce reliable and efficient forecasts of polar‐low (PL) trajectories 12 hours ahead. A temporal model (RLSTM) benefiting from the rolling‐forecast strategy, improves overall prediction accuracy and is suitable for quick experimentation, while a spatiotemporal model (PL‐UNet), incorporating both historical and
Ziying Yang, Rune Grand Graversen, Filippo Maria Bianchi, Jiping Liu, Ruibo Lei   +4 more
wiley   +1 more source

Contribution of global geopotential models to gravimetric geoid determination [PDF]

, 2018
Gravimetrik jeoit belirlemede global yerpotansiyel modellerinden, sayısal yükseklik modellerinden ve yersel gravite gözlemlerinden yararlanılır. Yeryuvarının tümüne homojen olarak yayılmış gravite gözlemlerinin değerlendirilmesiyle global yerpotansiyel ...
Demir, Selda
core  

Gravity field modelling and gravimetry

Geodesy and Cartography, 2015
The summary of research activities concerning gravity field modelling and gravimetric works performed in Poland in the period of 2011-2014 is presented.
Krynski Jan
doaj   +1 more source

How consistently do ensemble prediction systems represent the growth of atmospheric uncertainty?

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Spread‐based diagnostics calculated for 12 ensemble prediction systems are compared to understand the consistency with which they represent atmospheric uncertainty growth. Good correlation between all these systems is found in the extratropics for a lead time range from 48 hr to between 96 hr and 192 hr.
Douglas Wood, Suzanne Gray, John Methven, Mark Rodwell   +3 more
wiley   +1 more source

Accuracy assessment of GOCE-based geopotential models and their use for modelling the gravimetric quasigeoid - A case study for Poland

Geodesy and Cartography, 2014
Misja GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) przyczyniła się do znacznego poprawienia znajomości pola siły ciężkości Ziemi. W artykule przedstawiono wyniki oszacowania dokładności anomalii wysokości, wyznaczonych z globalnych ...
Godah Walyeldeen, Szelachowska Malgorzata, Krynski Jan   +2 more
doaj   +1 more source

Stratospheric and tropospheric seasonality and its implications for observation requirements in numerical weather prediction

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Daily time series of zonal‐mean zonal wind (m·s−1) at 10 hPa and 60° N from 1950 to 2021 from the ERA5 reanalysis. This shows huge variability in some seasons and very little in others. We provide evidence that high‐level observations, radiosonde and satellite, are more important during the extended winter season with its very large variability ...
Bruce Ingleby, Inna Polichtchouk
wiley   +1 more source

Analysis and Selection of the Best Global Geopotential Model for Lebanon

Emerging Science Innovation
Accurate transformation of Global Positioning System (GPS) derived ellipsoidal heights to orthometric heights necessitates the selection of an optimal Global Geopotential Model (GGM). This study aims to identify the most accurate freely available high-resolution GGM for Lebanon.
null Mohamed Issa, null Mohammad Abboud
openaire   +1 more source

An opportunity index to anticipate when subseasonal predictions are useful

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Simultaneously active subseasonal windows of forecast opportunity can be combined into a single opportunity index, which can be used operationally to anticipate enhanced or reduced subseasonal prediction skill. For predictions of temperature anomalies in Switzerland during summer—a region and season with particularly low predictability—skill can nearly
Dominik Büeler, Maria Pyrina, Adel Imamovic, Christoph Spirig, Daniela I. V. Domeisen   +4 more
wiley   +1 more source

Almost Everything You Always Wanted to Know About Representing Gravity in Global Models but Were Afraid to Ask

Journal of Advances in Modeling Earth Systems
For over 60 years, an approximation involving spherical geopotentials has underlain the representation of gravity in global numerical models of Earth's atmosphere and oceans. This article explores how departures from sphericity can be allowed by assuming
Andrew Staniforth, Andy White
doaj   +1 more source

An analysis of methods for gravity determination and their utilization for the calculation of geopotential numbers in the Slovak national levelling network

Contributions to Geophysics and Geodesy, 2016
The vertical reference system in the Slovak Republic is realized by the National Levelling Network (NLN). The normal heights according to Molodensky have been introduced as reference heights in the NLN in 1957.
Miroslava MAJKRÁKOVÁ, Juraj PAPČO, Pavol ZAHOREC, Branislav DROŠČÁK, Ján MIKUŠKA, Ivan MARUŠIAK   +5 more
doaj   +1 more source