A5020466912- Climate variability and models
- Meteorological Phenomena and Simulations
- Ecosystem dynamics and resilience
- Atmospheric and Environmental Gas Dynamics
- Complex Systems and Time Series Analysis
- Hydrology and Drought Analysis
- Topological and Geometric Data Analysis
- Energy Load and Power Forecasting
- Oceanographic and Atmospheric Processes
- Seismology and Earthquake Studies
- Landslides and related hazards
- Ionosphere and magnetosphere dynamics
- Cryospheric studies and observations
- Precipitation Measurement and Analysis
- Global Financial Crisis and Policies
- Aquatic and Environmental Studies
- Atmospheric Ozone and Climate
- Anomaly Detection Techniques and Applications
- Metabolomics and Mass Spectrometry Studies
- Tree-ring climate responses
- Reservoir Engineering and Simulation Methods
- Climate Change, Adaptation, Migration
- Geology and Paleoclimatology Research
- Earthquake Detection and Analysis
- Marine and coastal ecosystems
Karlsruhe Institute of Technology
2022-2025
ETH Zurich
2024
University of Bergen
2024
Uppsala University
2024
University of Oxford
2020-2023
Abstract Euro‐Atlantic regimes are typically identified using either the latitude of North Atlantic jet or clustering algorithms in phase space 500‐hPa geopotential (Z500). However, while robust trimodality is visibly apparent indices, Z500 clusters require highly sensitive significance tests to distinguish them from autocorrelated noise. This leads considerable decadal variability regime patterns, confounding many potential applications. A clear‐cut choice optimal number also hard justify....
Few classes of weather events have more acute or dramatic impacts on Europe than extreme rainfall. In a warmer world, both thermodynamical and dynamical factors will interact to alter European rainfall; its average characteristics, at seasonal-mean synoptic timescales. Understanding these changes is societally vital yet complex, as we are faced by the challenge that CMIP6 class models not able resolve rainfall directly. Meanwhile, kilometre scale simulations either limited in geographical...
This paper explores the use of Topological Data Analysis (TDA) to investigate patterns in zonal-mean zonal winds Arctic, which make up polar vortex, order better explain vortex dynamics. We demonstrate how TDA reveals significant topological features this data, and they may relate these collapse stratospheric during winter northern hemisphere. Using a time series representation we build point cloud using principles Takens' Embedding theorem apply persistent homology uncover nontrivial...
It has long been suggested that the mid-latitude atmospheric circulation possesses what come to be known as `weather regimes', loosely categorised regions of phase space with above-average density and/or extended persistence. Their existence and behaviour extensively studied in meteorology climate science, due their potential for drastically simplifying complex chaotic dynamics. Several well-known, simple non-linear dynamical systems have used toy-models atmosphere order understand exemplify...
Abstract A number of studies have investigated the large‐scale drivers and upstream precursors extreme weather events, making it clear that earliest warning signs events can be remote from impacted region in both time space. Integrating leveraging our understanding dynamical provides a new perspective on ensemble forecasting for focused building storylines possible event evolution. This then acts as tool raising awareness conditions conducive to high‐impact providing early their development....
Abstract. Stochastic forcing can, sometimes, stabilise atmospheric regime dynamics, increasing their persistence. This counter-intuitive effect has been observed in geophysical models of varying complexity, and here we investigate the mechanisms underlying stochastic dynamics a conceptual model. We use six-mode truncation barotropic β-plane model, featuring transitions between analogues zonal blocked flow conditions, identify similar to those seen previously work on low-dimensional random...
Abstract The accurate prediction of intense precipitation events is one the main objectives operational weather services. This task even more relevant nowadays, with rapid progression global warming which intensifies these events. Numerical models have improved continuously over time, providing uncertainty estimation dynamical ensembles. However, direct forecasting still challenging. Greater availability machine‐learning tools paves way to a hybrid approach, optimal combination physical...
We quantify the value of sub-seasonal forecasts for a real-world prediction problem: forecasting French month-ahead energy demand. Using surface temperature as predictor, we construct trading strategy and assess financial using meteorological forecasts, based on actual demand price data. show that with lead times greater than 2 weeks can have this application, both their own in conjunction shorter range especially during boreal winter. consider cost/loss framework example, while it captures...
Abstract. Even the most advanced climate models struggle to reproduce observed wintertime circulation of atmosphere over North Atlantic and western Europe. During winter, large-scale motions this particularly challenging region are dominated by eddy-driven highly non-linear flows, whose low-frequency variability is often studied from perspective regimes – a small number qualitatively distinct atmospheric states. Poor representation associated with persistent blocking events, or variations in...
Abstract The response of the Euro‐Atlantic wintertime circulation to climate change is deeply uncertain. Atlantic jet caught in a “tug‐of‐war” between rapid warming trends both tropics and Arctic leading debate over changing “waviness” jet, which subject strong non‐linearity internal variability. From complementary perspective weather regimes, there considerable uncertainty how atmospheric blocking will alter under change. By applying hybrid approach geopotential‐jet regimes 6th phase...
The occurrence of cold spells over different regions North America has been linked to windy extremes western Europe. These events – termed pan-Atlantic are mediated by an anomalous state the Atlantic storm track. While it is known that European windstorms modulated track, relative contribution American wind not easy quantify.In this study, two clustered with respect evolution large-scale circulation Atlantic. then ascertained using analogs, so states track can be compared for days and...
Abstract. The ever-increasing complexity and data volumes of numerical weather prediction demand innovations in the analysis synthesis operational forecast data. Here we show how dynamical thinking can offer directly applicable information, taking as a case study extreme northern Italy flooding May 2023. We compare this event with long-lasting historical rainfall events order to determine (a) why it was so extreme, (b) well predicted, (c) may improve our predictions such extremes. Lagrangian...
Abstract Weather regimes are recurrent and quasi‐stationary large‐scale atmospheric circulation patterns, typically linking to surface weather. Two commonly used sets of weather wintertime North American Euro‐Atlantic regimes. Notwithstanding recent evidence pointing a connection between winter in America Europe, there is little knowledge on the possible relation Here, we find that specific pairs show close visual statistical correspondence. Moreover, joint analysis two can provide...
© 2023 The Author(s). Published by the American Meteorological Society. This is an Author Accepted Manuscript distributed under terms of Creative Commons Attribution 4.0 International (CC BY 4.0) License . *Corresponding author e-mail: Steven Woolnough, s.j.woolnough@reading.ac.uk
Abstract. Even the most advanced climate models struggle to reproduce observed wintertime circulation of atmosphere over North Atlantic and Western Europe. During winter, this particularly challenging region is dominated by eddy-driven highly non-linear flows, which are often studied from perspective regimes – a small number qualitatively distinct atmospheric states. Poor representation associated with persistent blocking events, or variations in jet latitude, degrade ability correctly...
Abstract. In this paper we investigate the curious ability of stochastic forcing to increase persistence regimes, in a low-order, stochastically forced system. recent years, evidence from both simple models and climate simulations have suggested that can act as stabilising force regime persistence, but mechanisms driving potential reinforcement are unclear. Using six-mode truncation barotropic β-plane model, featuring transitions between analogues zonal blocked flow conditions, show moderate...
The accurate prediction of intense precipitation events is one the main objectives operational weather services. This task even more relevant nowadays, with rapid progression global warming which intensifies these events. Numerical models have improved continuously over time, providing uncertainty estimation dynamical ensembles. However, direct forecasting still challenging. Greater availability machine learning tools paves way to a hybrid approach, optimal combination physical models, event...
Abstract. The ever-increasing complexity and data volumes of numerical weather prediction demands innovations in the analysis synthesis operational forecast data. Here we show how dynamical thinking can offer directly applicable information, taking as a case study extreme north Italian flooding May 2023. We compare this event with historical rainfall events – order to determine a) why it was so extreme, b) well predicted, c) may improve our predictions such extremes. Lagrangian shows, line...
Weather regimes are recurrent and quasi-stationary atmospheric circulation patterns, typically linking to surface weather extremes. Despite their widespread use, little is known on whether or how defined in different regions relate each other reflect long-distance teleconnection patterns. Here, we shed light this knowledge gap, focussing North American Euro-Atlantic regimes. The selection of these two motivated by recent evidence pointing a systematic connection between winter America...
Weather regimes are recurrent and quasi-stationary large-scale atmospheric circulation patterns, typically linking to surface weather. They have been defined over multiple regions used in a range of practical applications, including forecasting, the study trends climate model evaluation. Despite their widespread use, extent which reflect physical modes atmosphere is seldom investigated. Similarly, statistical connections between weather different geographical largely left unstudied. Here, we...