Eswyn Chen

Profile

I am a 2nd-year PhD student at the Institute for Climate and Atmospheric Science (ICAS) working on the improvement of climate predictions for Europe in a Met Office CASE-funded project. My PhD project is motivated by a persisting enigma in climate prediction known as the ‘signal-to-noise paradox’—a counterintuitive and troubling phenomenon in which climate models underestimate the fraction of predictable signal in the real world. It has been proposed that mesoscale air-sea interactions on sharp sea surface temperature (SST) fronts are important drivers of North Atlantic climate variability. As such, the ‘missing physics’ that contributes to the ‘signal-to-noise paradox’ could potentially be one of these frontal processes that current models are yet to be able to resolve. To address this issue, I work with the Met Office Hadley Centre, the US National Center for Atmospheric Research (NCAR), and Imperial College London to investigate the interactions between small-scale transient eddies and the larger-scale mean flow over the North Atlantic using high- to ultrahigh-resolution climate models.

As a first step, I am studying the representation of North Atlantic extratropical cyclones and the midlatitude storm track in climate models of different horizontal resolutions to see if previously unseen frontal processes could indeed be resolved in higher-resolution models. If models with inbuilt abilities to resolve weather-scale dynamics could reproduce signals in the same strength as seen in observation, it would indicate that the contributing processes to the ‘signal-to-noise paradox’ occur on these fine scales and that one could begin to identify what they might be. Work will continue on the predictability of basin-scale climate variability from eddy-mean flow feedbacks, and to pin down an explanation and a solution to model underconfidence.

Prior to my PhD, during the latter part of my undergraduate degree at the University of Cambridge, I studied the statistical relationship between Arctic SST and the evolution of the North Atlantic summer jet stream using a bespoke MATLAB programme to locate the jet and track its changes over the satellite era. I remain highly interested in the changes in midlatitude summer circulation patterns and how they relate to extreme weather events such as heat waves.

During my time at Cambridge, I also worked as the Physical Geography Editor and the Editor-in-Chief of Cambridge’s own in-house geographical journal magazine, Compass. My role was to source and edit submissions for the Physical Geography section of the magazine, write my own entries, and oversee the production of the magazine as well as its outreach campaigns. I hope to be able to carry on with similar work in scientific communication and editing over the course of my PhD if opportunities arise.

Research interests

• Synoptic climatology
• North Atlantic climate variability
• Midlatitude atmospheric dynamics
• High-resolution climate modelling
• Extratropical storm track
• Jet stream anomalies
• Arctic amplification
• Extreme weather
• Heat waves

Qualifications

• BA (Cantab.) Geography, University of Cambridge, 2021

Research groups and institutes

• Institute for Climate and Atmospheric Science
• Atmospheric and Cloud Dynamics
• Climate Science and Impacts