Flood-Inducing Atmospheric and Antecedent Conditions: Variation and Change Across the UK and Europe

The aim of this project is to identify extreme flood-inducing atmospheric patterns (and antecedent conditions) and understand how they vary both spatially (across different hydroclimates in the UK and Europe) and temporally (over past and future decades). The work will also identify the worse-case scenario of these driver for inducing different types of flood events and how this relationship varies spatially and temporally.

Floods have severe socioeconomic and environmental impacts across the UK and Europe. They also can result in loss of life. During 2021, flooding across Belgium and Germany killed an estimated 200 people. In 2022, Storm Eunice in the UK was labelled the most severe storm in decades, resulting in severe flooding across the country which disrupted transport links and damaged infrastructure (Fekete & Sandholz, 2021; Met Office, 2022). The IPCC has also warned that with further increase in temperatures, the damage that future flood events could have may be devastating and irreversible. Research into
understanding flood variability and flood inducers if therefore vital for mitigation measures as climate change is set to intensify the hydrological cycle and result in more extreme events (IPCC, 2022; Pattinson & Lane, 2011; Wilby & Quinn, 2013). Flood frequency and intensity is projected to increase into the future as the climate changes, across the UK and Europe. The variability and distribution temporally and spatially of this, however, is not clearly understood and will differ depending on regional antecedent conditions and hydroclimates. Furthermore, floods will vary depending on seasonal and decadal variability. Historical paleoclimate studies suggest that flood-rich periods occurred during cold weather, whilst other contemporary studies suggest that floods will increase as global temperature increase, due to elevated atmospheric water content. Although as temperatures increase, precipitation is set to increase as the atmosphere can hold more water, whether this translates into flood
events is less clear (Bronnimann et al, 2022; Met Office, 2022; Stucki et al, 2012). It is therefore important to understand the historical and current relationship between atmospheric and antecedent conditions for inducing flood events, so that future projections based on increasing temperatures and atmospheric water content can be made more accurate. There is also a lack of evidence to suggest that the changes in flood regimes over the last two centuries are linked to anthropogenic climate change, and future projections are not fully clear and accurate (Bronnimann et al, 2022).

Changes in flood frequency and intensity are dependent on a multitude of different inducers, such as atmospheric and antecedent conditions (Nied et al, 2014). In my project I will study the relationship between different types of flood events and these inducers across varying hydroclimates in the UK and Europe will be studied in this project. The variability of this relationship on different temporal scales such as the sub -seasonal and decadal will be studied. This DTP project will look at classifying atmospheric patterns (AOPP subdepartment) and use antecedent and hydrological data (SoGE department) to study how these drivers induced different flood type events over time and space across the UK and Europe (Supervisors from Oxford and University of Freiburg). To date, the relative importance of
atmospheric and antecedent conditions inducing flood events and how this may change with climate change is unclear. It is also important to understand how these variables could potentially change into the future. The relationship between the variable temperature, precipitation and flood events will also be considered at the individual meteorological variable scale to contribute to this research gap. This project is interdisciplinary and will require the understanding of the atmosphere and hydrosphere (hence the request for visiting status at AOPP).