Current Research

Tropical cyclone (TC) intensification under moderate vertical wind shear (VWS)

Moderate deep-layer (200-850 hPa) VWS is typically an inhibiting factor for TC formation and intensification. However, there are numerous examples of TCs in nature that intensify in environments characterized by moderate VWS. For example, Hurricanes Katia (2011) and Ophelia (2011) intensified from weak tropical storms to strong hurricane in the presence of VWS greater than 8 m/s. As these cases pose substantial challenges to weather forecasters, understanding why and how some TCs intensify under moderate VWS could have important implications for TC prediction.

As part of my PhD research, I am taking a multi-case perspective at this problem by employing both ensemble modeling and climatological analysis. My work using an ensemble approach was recently published as a two-part paper in the Journal of the Atmospheric Sciences (references and summary schematics in this page). I am currently developing the climatological analysis, but you can see some preliminary results in my extended abstract for the 32nd AMS Conference on Hurricanes and Tropical Meteorology.

References:
  • Rios-Berrios, R., 2016: Climatological Analysis of Tropical Cyclone Intensity Changes under Moderate Vertical Wind Shear. Preprints, 32nd Conf. on Hurricanes and Tropical Meteorology, San Juan, Puerto Rico, Amer. Meteor. Soc., 9D.4. [Link]
  • Rios-Berrios R., R. D. Torn, and C. A. Davis, 2016: An ensemble approach to investigate tropical cyclone intensification in sheared environments. Part II: Ophelia (2011). J. Atmos. Sci., in press. [Link]
  • Rios-Berrios R., R. D. Torn, and C. A. Davis, 2016: An ensemble approach to investigate tropical cyclone intensification in sheared environments. Part I: Katia (2011). J. Atmos. Sci., 73, 71-93. [Link]

     

Sensitivity of TC spinup to dry air

Another inhibiting factor for TC formation and intensification is environmental dry air. While this inhibiting characteristic has been long recognized in literature, a quantitative assessment is necessary to understand why and how dry air impacts TC development. I am currently tackling this problem on a collaborative project with professors Brian Tang and Kristen Corbosiero, and fellow classmates Joshua Alland and Jeremy Berman. We have produced a set of idealized numerical simulations with different moisture profiles, and we are analyzing those simulations with water vapor, angular momentum, and mean available enthalpy budgets.

References:
  • Tang, B., R. Rios-Berrios, J. Alland, J. Berman, and K. Corbosiero, 2016: Sensitivity of axisymmetric tropical cyclone spin-up time to dry air aloft. J. Atmos. Sci., submitted.
  • Rios-Berrios R., J. A. Alland and J. Berman, 2014: Tropical cyclone development in different moisture environments: A budget approach. Down to Earth department, Physics Today. [Link]