Summary 🌀🌧
During my career in academia I wrote lead-author papers in renowned journals covering a number of extreme weather phenomena in the midlatitudes and tropics. Plain-language summaries of these papers are provided below; if you’re interested in discussing the results of any of these studies in more detail, please do get in touch.
Lead-author papers
Examining the dynamics of a Borneo vortex using a balance approximation tool – Hardy et al. (2023)
We examined a type of storm called a Borneo vortex case using computer simulations and satellite observations. The vortex is identified with high humidity through the atmosphere and has heaviest rainfall on its northern flank. Simulations represent circulation and rainfall accumulation well. The low-level Borneo vortex is coupled with a higher-level wave, which moves westwards along a layer with a sharp vertical gradient in moisture. Vortex growth occurs through mechanisms usually considered outside the tropics.
We studied a powerful typhoon called Nepartak that rapidly intensified in the western North Pacific in 2016, using computer simulations to understand how the storm’s inner core changed and why the storm intensified so quickly. We found that the inner core of the storm sometimes changed shape, alternating between a ring shape and a single, solid structure. When the storm was in the ring shape phase, its swirling winds got stronger, but in the solid structure phase, the winds stayed about the same. Overall, this study shows that to understand how storms like Nepartak grow and change, scientists need to consider not just the storm itself, but also the smaller, random motions within the storm.
In late September 2012, heavy rainfall caused major flooding in northern England and north Wales due to a slow-moving midlatitude cyclone. This cyclone intensified over the United Kingdom, influenced by a swirling mass of air called a potential vorticity (PV) anomaly. Computer simulations revealed that weakening the PV anomaly decreased rainfall, indicating its strength was linked to the flooding severity. Unexpectedly, strengthening or moving the anomaly away from the cyclone also reduced rainfall, suggesting the flood conditions were nearly as severe as possible given the initial PV anomaly’s position and strength.
In late September 2012, heavy rainfall caused major river flooding in northern England and north Wales, with some areas receiving nearly 200 mm of rain. This flooding was triggered by a slow-moving weather system called a midlatitude cyclone, which formed after a swirling mass of air called a potential vorticity (PV) streamer interacted with a tropical storm near the Azores. As the PV streamer moved poleward, it drew moist air from the tropics, leading to intense thunderstorms that released heat and fractured the PV streamer, causing it to break away from the main mass of air. Computer simulations showed that this intense heating within the thunderstorms drastically altered the development of the cyclone, highlighting the importance of understanding these cloud-related processes for predicting extreme weather events.