John Molinari

John Molinari

Tropical cyclone formation and intensity change; monsoons and large-scale tropical meteorology

The World Within Reach
John Molinari
Research Professor

College of Arts and Sciences
Department: Atmospheric and Environmental Sciences


ES 225




Because so little is known about them, tropical cyclones remain one of the most challenging phenomena to study in meteorology. This makes them especially suitable for MS and PhD research projects, because many discoveries remain to be made! These are a list of some of the topics we are addressing:

How exactly do hurricanes form? We know the large-scale requirements reasonably well, but how does nature evolve from a synoptic-scale disturbance to a mesoscale tropical depression? We know surprisingly little about this. We are using radar, satellite, aircraft reconnaissance, lightning, dropsondes, and various other data sources to address these questions. Our focus has been on the role of intense local convective cells in storm development, and such questions as how does an eyewall actually form?

The role of vertical wind shear in tropical cyclones at all stages. Several of our studies have focused on storms that “broke the rules” by intensifying when vertical wind shear was large. We are also interested in what happens to tropical cyclones when they are approached by midlatitude troughs. This is one of least understood aspects of tropical cyclone intensity prediction.

Our most recent research project involves the cirrus canopy of tropical cyclones. This represents one of the most dramatic cirrus clouds in the tropics. The cirrus top reaches into the stratosphere in the storm core, where the cloud is 4 km thick, and thins and subsides with radius. We have studied many aspects of the cirrus canopy, including outflow jets, transverse bands, and extreme turbulence.

Large-scale tropical waves and monsoons. We are interested in monsoon troughs worldwide and what role they play in tropical cyclone formation. We also study “equatorial wave modes” and the Madden-Julian Oscillation. Equatorial waves can have bizarre structure by midlatitude standards, such as maximum wind speed at the center of lows and highs in a Kelvin wave; or the simultaneous presence of nearly identical low pressure areas at the same latitude in each hemisphere, which can lead to “twin” tropical cyclones. We do synoptic studies of the evolution of these waves. Finally, we study “monsoon gyres”, which are gigantic low pressure areas in the subtropics than can spawn multiple tropical cyclones.

Past and Present Thesis Topics

Sarah Ditchek, PhD, in progress: diurnal cycles in tropical cyclones

Patrick Duran, PhD, in progress: tropopause evolution during tropical cyclone intensification

Erin Dougherty, MS: Hurricane Bonnie (1998): Maintaining Intensity during High Vertical Wind Shear and an Eyewall Replacement Cycle

Michaela Rosenmayer, MS: Turbulence in the Upper Levels of Tropical Cyclones

Leon Nguyen, PhD: The Intensification of Sheared Tropical Cyclones

Steven Fuhrman, MS: Global View of the Role of the ITCZ/Monsoon Trough in Tropical Cyclogenesis

Diana Thomas, MS: A WRF Simulation of the Asymmetric Rapid Intensification and Trough Interaction of Tropical Storm Gabrielle (2001)

Brian Crandall, MS: An Analysis of the Formation and Evolution of the 1989 Western North Pacific Gyre

Kay Shelton, PhD: Easterly Waves and Tropical Cyclogenesis in the Caribbean

Carl Schreck, PhD Role of Equatorial Waves in Tropical Cyclogenesis

Jaclyn Frank, MS Evolution of a Tropical Storm in Strong Vertical Wind Shear

Carl Schreck, MS Equatorial Rossby Waves and Twin Tropical Cyclogenesis

Kay Shelton, MS Thermodynamic structure of tropical cyclones from aircraft reconnaissance.

Kristen Corbosiero, PhD The structure and evolution of a hurricane in vertical wind shear.

Kelly Lombardo, MS Influence of equatorial Rossby waves on tropical cyclogenesis in the western Pacific.

Anantha Aiyyer, PhD Evolution of Equatorial and Tropical Disturbances in Nonuniform Environments

Daniel Lipper, MS Regions of Intense Convection in the Core of Tropical Cyclones

Michael Dickinson, PhD Influence of Large-Scale Inhomogeneities on Tropical Wave Growth and Subsequent Tropical Cyclogenesis

Kristen Corbosiero, MS The Effects of Vertical Wind Shear and Storm Motion on the Distribution of Lightning in Tropical Cyclones

Deborah Hanley, PhD Composite Study of Hurricane-Trough Interactions (co-advisor D. Keyser)

Anantha Aiyyer, MS Numerical Modeling of the Interactions of Tropical Cyclones and Upper Tropospheric Troughs

Gretchen Heller M.S. Lightning Variations in Landfalling Tropical Cyclones.

Mike Turk M.S. Tropical Cyclogenesis in the Eastern Pacific.

Jeff Freedman M.S. Meteorological Factors Associated with Positive Lightning Flashes (jointly with Prof. Idone).

Steve Skubis Ph.D. Potential Vorticity Evolution During Convective Outbreaks.

Steve Skubis M.S. Evolution of the Surface Wind Field of an Intensifying Tropical Cyclone.

Mike Dudek Ph.D. Simulation of Convective Complexes Using a Three-Dimensional Mesoscale Model.

Dave Vollaro M.S. External Influences on Hurricane Intensity.

Frank Robasky M.S. Large-scale Forcing and Secondary Eyewall Formation in Hurricane Allen.

Dan Peterson M.S. Atlantic Hurricane Intensification Climatology.

Ron Morales M.S. Interaction of a Landfalling Hurricane with a Front (jointly with Prof. Bosart).

Frank Alsheimer M.S. Genesis of Hurricane Danny (1985) in the Gulf of Mexico.


B.S.  Meteorology  (1971)  Pennsylvania State University
M.S.  Meteorology  (1975)  Florida State University
Ph.D. Meteorology  (1979)  Florida State University

Research Interests

Tropical cyclone formation and intensity change; Role of vertical wind shear at all stages of tropical cyclones; Lightning in tropical disturbances; Tropical waves; Monsoons and monsoon disturbances. We do both observational and high-resolution numerical modeling studies.


John Molinari's publications, with links to PDFs.