Results 31 to 40 of about 615 (153)

Ensemble reliability and the signal‐to‐noise paradox in ECMWF subseasonal forecasts

Quarterly Journal of the Royal Meteorological Society, EarlyView.
We derive a general expression for the ratio of predictable components (RPC) in terms of correlation, spread–error ratio, and total variance ratio. Physical constraints on the admissible solutions (i.e., real‐valued and non‐negative variances) provide a mechanism to identify statistically paradoxical sample combinations of reliability and correlation ...
Christopher D. Roberts, Frederic Vitart
wiley   +1 more source

Scaling turbulence drives the general circulation

Quarterly Journal of the Royal Meteorological Society, EarlyView.
The NOAA Gulfstream SP4, which deployed the GPS dropsondes over the NE Pacific Ocean as part of the Winter Storms Project during the January–March periods of 2004, 2005 and 2006. Abstract Statistical multifractal analysis of airborne and dropsonde observations is used to show that persistence of velocity after molecular collisions breaks the continuous
Adrian F. Tuck
wiley   +1 more source

The role of stratosphere-troposphere coupling in the occurrence of extreme winter cold spells over northern Europe

Journal of Advances in Modeling Earth Systems, 2012
Extreme cold spells over Northern Europe during winter are examined in order to address the question to what degree and in which ways stratospheric dynamics may influence the state of the troposphere.
Lorenzo Tomassini, Mark P. Baldwin, Felix Bunzel, Marco Giorgetta   +3 more
doaj  

Impact of Weak‐Constraint Four‐Dimensional Variational data assimilation on the prediction of a sudden stratospheric warming event in 2024

Quarterly Journal of the Royal Meteorological Society, EarlyView.
The Weak‐Constraint Four‐Dimensional Variational (WC‐4DVAR) system markedly improved the analysis and forecasting of the 2024 sudden stratospheric warming (SSW) event. It reduced biases and enhanced 7–9 day predictions of temperature across the SSW life cycle, with the most pronounced gains for winds also during the critical onset period.
Shaoying Li, Weimin Zhang, Shuo Ma, Bainian Liu, Yanlai Zhao, Xiaoqun Cao   +5 more
wiley   +1 more source

Dry intrusions and warm‐core development in Medicanes: Insights from a multi‐case analysis and the peculiar evolution of Ianos

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Mediterranean tropical‐like cyclones show a clear seasonality, with September cyclones exhibiting the deepest convection and Ianos representing the most extreme case. While one or more dry intrusions are typically detected during the cyclone life cycle, Ianos instead features two much weaker descending airflows.
Daniele Nigro, Lorenzo Giovannini, Simona Bordoni, Stavros Dafis, Mario Marcello Miglietta   +4 more
wiley   +1 more source

North American cooling signature of strong stratospheric wave events depends on the QBO phase

Environmental Research: Climate
Extreme stratospheric wave activity has been linked to surface cold extremes over North America, but little is known whether the Quasi-biennial Oscillation (QBO) plays a role in this linkage. Here, by comparing strong stratospheric wave events during the
Xiuyuan Ding, Gang Chen, Gudrun Magnusdottir   +2 more
doaj   +1 more source

Stratospheric initial conditions provide seasonal predictability of the North Atlantic and Arctic Oscillations

Environmental Research Letters, 2019
The North Atlantic Oscillation (NAO), the regional manifestation of the Arctic Oscillation (AO), dominates winter climate variability in Europe and North America.
Yu Nie, Adam A Scaife, Hong-Li Ren, Ruth E Comer, Martin B Andrews, Philip Davis, Nicola Martin   +6 more
doaj   +1 more source

Asymmetry in the effect of North Atlantic sea surface temperature on the eddy‐driven jet

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Projections of climate over Europe and the Atlantic are uncertain due to the uncertainty surrounding future changes in North Atlantic sea surface temperatures (SSTs). Here, we demonstrate that warming in the North Atlantic Ocean is linked to a transition to a negative phase of the North Atlantic Oscillation, as well as to an equatorward displacement of
Paul‐Arthur Monerie, Jon Robson, Christopher O'Reilly, Rowan Sutton   +3 more
wiley   +1 more source

Characteristics of upper‐level updrafts and downdrafts in the anvils of tropical deep convective clouds

Quarterly Journal of the Royal Meteorological Society, EarlyView.
This study investigates the thermodynamic and microphysical characteristics of updrafts and downdrafts of tropical deep convective anvil clouds using in situ measurements. We found that parts of the downdrafts are in ice supersaturation in these clouds.
Sreehari Kizhuveettil, Jordi Vila‐Guerau de Arellano, Martina Krämer, Armin Afchine, Luiz A. T. Machado, Martin Zöger, Wiebke Frey   +6 more
wiley   +1 more source

Further development of adaptive parameter tuning in the numerical weather prediction models of Deutscher Wetterdienst

Quarterly Journal of the Royal Meteorological Society, EarlyView.
The introduction of adaptive parameter tuning in the numerical weather prediction models of DWD in 2022 substantially improved the forecast quality of near‐surface variables like 2‐m temperature and 2‐m humidity. Since 2023, refinements and extensions, primarily affecting the surface evaporation and its diurnal cycle, have led to further advances ...
Günther Zängl
wiley   +1 more source