Overview

My research field is very high resolution global climate projections of extreme wind speeds, and climate modelling of sub-grid boundary-layer momentum transport, with a focus on a novel parameterization that directly prognoses sub-grid momentum fluxes. My research interests also include how air-sea interactions affect extreme wind speeds associated with midlatitude cyclones, as well as methodologies to identify the mid-latitude cyclones mesoscale features associated with the extreme winds and gusts events.

Climate Modelling of Sub-grid boundary-layer momentum transport 

Midlatitude Cyclones, Tropical Cyclones (TCs), shallow cumuli, and low-level jets (LLJs) are all significant phenomena in the climate system. However, effectively representing them in climate models has been historically challenging. One contributing factor to climate model deficiencies lies in the inadequate parameterization of subgrid momentum fluxes in the atmospheric boundary layer. In current-generation climate models, momentum parameterization suites often rely on crude methods like downgradient diffusion combined with a separate cumulus momentum transport scheme. This approach has limitations, especially in cases where a near-surface jet in the wind profile leads to upgradient momentum fluxes at the top of the jet maximum, even without deep convection.

My research focuses on implementing a novel parameterization of momentum transport that directly prognoses subgrid momentum fluxes. This approach differs from conventional methods but aligns more closely with the governing equations, making it more flexible and general. Notably, it can predict upgradient momentum fluxes, offering an advantage over existing approaches. To achieve this goal, I am examining the process of momentum transport using a comprehensive hierarchy of observations and models. By gaining a deeper understanding through these studies, I am refining and testing the prognostic equations for momentum fluxes within the GFDL atmospheric climate model AM4. 

Assessment of very high resolution global climate projections of extreme wind speeds under global-warming scenarios

Extensive research on midlatitude cyclones and their associated extreme winds and intensity has been conducted using models ranging from coarse (~100km resolution) to high-resolution (~25km) in both the Northern Hemisphere and the Southern Hemisphere. Particular emphasis has been placed on the North Atlantic region and North Western Europe. Recently, the development of global climate kilometre-scale (also known as k-scale) modeling capabilities in various meteorological and climate centers worldwide (GFDL, Met Office, ECMWF, NCAR, etc.) has opened up unprecedented opportunities to explore the benefits of convection-permitting simulations. These simulations have the potential to significantly improve the accuracy and enhance the physical representation of Earth System feedbacks, thereby reducing uncertainties and associated risks in global climate projections of midlatitude cyclones.

In my research, I investigate the changes in the structure of midlatitude cyclones' wind speed, gusts, and other associated meteorological processes, ranging from mesoscale to kilometre scale, under pseudo-global warming scenarios.