Tropical cyclone intensification

Tropical cyclones (TCs) are among nature’s most powerful phenomena, yet accurate forecasts of TC intensity change still remain a challenge. To that end, the main goal of my research is to improve physical understanding of TC intensification. I employ numerical modelling of TCs in an idealized framework using open-source NCAR Cloud Model (CM1). In particular, I investigated how various environmental factors, such as latitude and sea surface temperature, affect early period of TC intensification, including that of rapid intensification (Črnivec et al., 2016). For this purpose, I first implemented a TC-like vortex as a new initalization option into CM1 model. The subsequent numerical experiments relate to the prototype problem for TC intensification assuming an f-plane and employ the Dunion moist tropical sounding (Dunion, 2011) to characterize the background thermodynamic TC environment, which is widely used in idealized TC modelling. The Dunion sounding, however, is based on the observations in the Carribean and the question that we addressed in a follow-up study (Črnivec and Smith, 2016) is to what extent is the Dunion sounding representative to TC environments in other parts of the globe. I therefore derived mean radiosonde soundings for the Australian monsoon/cyclone season (for the Willis Island, Darwin and Weipa stations), documented their various characteristics and finally examined how do they control vortex amplification. The arguments were based on an axisymmetric perspective, invoking the classical axisymmetric spin‐up mechanism. As an upgrade, we currently investigate the relevance of non-axisymmetric features on the intensification process (Montgomery et al., 2019, in revision).

Cloud-radiation interaction

In addition, I study cloud-radiation interaction in order to improve its representation in weather and climate models. More coming soon, stay tuned!