Jenni L. Evans

Jenni L. Evans

  • Interim Director, Institute for CyberScience
  • Professor of Meteorology
509 Walker Building
University Park, PA 16802
Email: Jenni.Evans@psu.edu
Phone: (814) 865-3240

Education:

  1. PhD -- Monash University (Applied Mathematics)
  2. B.Sc. (Honors) -- Monash University (Applied Mathematics)

Research Specialties:

Climate:

Climate change impacts in the convective tropics

Climate modulation of tropical cyclone activity

Numerical Weather Prediction:

Dynamic evolution of tropical cyclones

Utilization of ensemble simulations for predictability

Tropical Meteorology:

Extratropical transition of tropical cyclones (ET)

Tropical cyclogenesis and subtropical cyclone formation

Factors governing tropical cyclone intensity, TC boundary layer

Statistical Meteorology:

Path clustering applied to ensemble forecasts of tropical cyclone track and structure

Point clustering applied to tropical cyclone climatologies, and forecast validation

Dimension reduction

Convection Studies:

Organization of convection in West Africa

Biography:

Brief Bio

Jenni L. Evans is a Professor of Meteorology at The Pennsylvania State University. Dr. Evans’ research encompasses tropical cyclones from genesis to decay, extratropical transition [ET], or landfall. The impacts of climate change on tropical cyclones [TCs] and other organized tropical convective systems are also key components of her research.

Jenni Evans was one of a small group of scientists who developed a new understanding of extratropically transitioning tropical cyclones, systems such as Hurricane Sandy of 2012. These systems can have potentially devastating societal impacts far from their tropical genesis – even in Scandinavia and Japan. Inspired by the need to characterize the structural evolution of ET events, she collaborated on developing a framework for mapping the structural evolution of cyclonic storms, the Cyclone Phase Space (CPS). The CPS is used in operations, including at the US National Hurricane Center.

In her recent research, Dr. Evans has employed a variety of novel statistical methodologies for (1) physically-based partitioning of ensemble forecasts of tropical cyclones; and (2) developing a metric for tropical cyclogenesis activity in climate change simulations. She has explored the relationships between organized convection and TC intensity with sea surface temperature [SST] and the implications of these relationships in a warming climate. The impact of realistic TC boundary layer structures and treatment of sea spray on TC potential intensity and the impacts of convection and topography on development of African Easterly Waves [AEWs] are also current areas of investigation. The tools of her research include observational diagnostics; statistical analyses and modeling of observations, simulations and reanalyses; and dynamical modeling. Her research is richer in many ways because of her students and key colleagues.

Jenni Evans has a strong commitment to science communications. Over the last few years, she has contributed to the development of a growing science communications program across Penn State (such as SciComm month). This has led her into many new experiences, including the NSF-funded NBC Learn series on Natural Hazards.

Dr. Evans is a Fellow of the American Meteorological Society (AMS) and served on its Council from 2005 to 2008. She co-chaired the World Meteorological Organisation (WMO) 8th Intergovernmental Workshop on Tropical Cyclones (Seoul, Republic of Korea; December 2014) and has served for over a decade as the Lead Meteorologist for the Professional Team assisting the Florida Commission on Hurricane Loss Projection Methodology. Other current and former professional service include the US Weather Research Program Science Steering Committee, Science Steering Committee for the US THORPEX Pacific Asian Regional Campaign, Advisory Board for the NOAA/NSF Developmental Testbed Center, Editor of Monthly Weather Review and Associate Editor of Weather and Forecasting.

 

Research Interests

Tropical cyclones [TCs], tropical climate and climate change, extratropical transition [ET], tropical convective organization and drivers.

The tropics are the boiler room of the atmosphere and the source of weather and climate phenomena that can have profound impacts across the globe. I am particularly interested in the interactions of tropical convection, tropical cyclones and the tropical climate system – and how these interactions manifest on timescales of days to centuries. The tools of my research include observational diagnostics; statistical analyses and modeling of observations, simulations and reanalyses; and dynamical modeling. Collaborations with my students and colleagues enrich my research and make me happy.

My curiosity about the likely changes in TC frequency and intensity with climate change led me to explore the relationships between organized convection and TC intensity with sea surface temperature [SST] and the implications of these relationships in a warming climate [e.g. Ryan et al. 1992; Evans 1993; Evans et al. 1994; Lighthill et al. 1994; Watterson et al. 1995; Dutton et al. 2000; Evans and Jaskiewicz 2001; Tsakraklides and Evans 2003; Fan et al. 2010, 2012; Waters et al. 2012; Evans and Waters 2012; Kozar et al. 2012, 2013; Evans and Webster 2014].

Storms such as Hurricane Sandy of 2012 belong to the class of Extratropically Transitioning tropical cyclones [ET events]. These systems can have potentially devastating societal impacts as far from their tropical genesis as Scandinavia, Japan or New Zealand. In the late 1990s, the importance of these events began to be realized [Jones et al. 2003]. My group documented the ET climatology for the North Atlantic [Hart and Evans 2001] and developed the Cyclone Phase Space (CPS) to map the structural evolution of ET systems [Hart 2003; Evans and Hart 2003]. Subsequent studies included analyzing the pathways to ET [Arnott et al. 2004; Hart et al. 2006] and examining them using both realistic and idealized numerical simulations [Prater and Evans 2002; Kimball and Evans 2002; Evans and Prater-Mayes 2004]. We developed metrics to track the (poor!) forecast model skill at capturing structure changes during ET [Evans et al. 2006; Veren et al. 2009] and applied clustering methodologies to objectively partition ensemble forecasts of ET [Keller et al. 2011; Kuruppumullage Don et al. 2015]. The use of clustering to explore the sensitivity of ET evolution to the TC and environment conditions is an active area of my research in collaboration with Francesca Chiaromonte, Alex Kowaleski, Sarah Jones, Julia Keller and Prabhani Kuruppumullage Don.

The impacts of realistic TC boundary layer structures and treatment of sea spray on TC potential intensity [Kowaleski and Evans 2015a, b] and the impacts of convection and topography on the development of African Easterly Waves [Hamilton et al. 2015] are other active areas of investigation and subtropical cyclones continue to distract me [Guishard et al. 2007, 2009; Evans and Guishard 2009; Evans and Braun 2012; González-Alemán et al. 2015].

Teaching interests

Tropical meteorology, climate and climate change, atmospheric dynamics, fluid dynamics.

My background in applied mathematics – particularly, geophysical fluid dynamics – led to my interest in teaching dynamics classes at all levels. Interpretation and manipulation of the equations provides a sound basis from which to understand and forecast the atmosphere.

Tropical storms (from thunderheads to hurricanes) have fascinated me since Cyclone Tracy devastated Darwin on Christmas Day in 1974. This love of tropical meteorology has drawn me to study tropical cyclones "from soup to nuts" to gain an understanding of the role of the tropics in the global climate system. These topics are encompassed in my undergraduate (stronger forecasting focus) and graduate (more theoretical) classes in tropical meteorology.

Anomalies in the tropics (whether individual storms, seasonal or longer) can impact higher latitude weather, thus having implications for forecasting all around the globe. I regularly offer graduate seminar courses.

Professional Affiliations

Selected Professional Service     

Chair, Search Committee for the Inaugural Director of the Penn State Water Institute (2015 – )

Executive Committee, Penn State Research IT Governance (2015 – )

Co-chair, PSIEE/EESI Science Communications Workshops (2014 – )

Awards and Fellows Nominations Committee, American Meteorological Society (2013 – )

Subject Matter Expert, ESCAP/WMO Typhoon Committee (2012 – )

Hurricane Risk Modeling Review Team, South Carolina Department of Insurance (2012 – 2013)

Science Advisory Board, NOAA/NCAR Developmental Testbed Center (DTC) (2011 – )

Nominations Committee for President and Councilors, American Meteorological Society (AMS) (2011 – 2014)

Reviewer, US National Academy of Sciences ReportWeather Services for the Nation: Second to None” (2011)

Co-Chair, 8th International Workshop on Tropical Cyclones (IWTC-VIII), World Meteorological Organisation (WMO), Republic of Korea (2010 – 2014)

Co-Chair, Agencia Estatal de Meteorología National Workshop on Subtropical Cyclones and Extratropical Transitions, Madrid, Spain (2008)

Executive Committee, Board on Oceans and Atmosphere, Association of Public and Land-grant Universities (APLU) (2007 – 2009)

US Science Steering Committee, The Observing System Research and Predictability Experiment (THORPEX) (2006 – 2009)

US Science Steering Committee, THORPEX/ T‑PARC (Pacific Asian Regional Campaign) (2006 – 2008)

National Science Board Panel “Towards a national agenda for hurricane science and engineering” (2006)

Councilor (elected), American Meteorological Society (AMS) (2005 – 2008)

Editor, Monthly Weather Review (2005 – 2007)

Professional Team Lead Meteorologist, Florida Commission on Hurricane Loss Projection Methodology (Florida State Board of Administration) (2003 – )

Science Team, United States Army Tropical Test Facility Relocation Initiative (1998 – 2000)