Earth Sciences Division Staff: Travis A. O'Brien

Biographical Summary

Travis O'Brien is a postdoctoral fellow working with Professor Bill Collins.  His research centers on understanding the physical processes that determine the climates of various regions, and how such processes and regional climates may change in the future.  He is presently focused on the characterization, development, and application of climate models for studies of coastal climatology.

Research Interests

Climate models are our one of our primary tools for investigating climatological processes and for developing detailed theories about how the climate system works.  Climate modeling can be viewed as a cycle that has three main stages: model development, model characterization, and model application.  As observation- and model-based studies improve our understanding of the natural world, it is often necessary to improve climate models in order to investigate new questions; model development is the stage in which we build new information into our climate models.  It is important to understand the properties of these models in order to understand ways in which model phenomena may reflect natural phenomena; model the characterization, which includes model validation, is the stage in which we develop a thorough understanding of the model itself and of how well the model represents nature.  Climate model application is the stage in which we use a climate model to gain new understanding about how the natural climate system works.  Travis is involved in all three stages of climate model-based research.

Model Characterization

Travis is currently investigating how and why resolved cloud systems in the Community Atmosphere Model change with model resolution (O'Brien et al.; 2013, J. Climate). He is also developing a satellite-based climatology of coastal fog for the purposes of climate model evaluation and for climate process studies. He has published studies on the impact of intrinsic model variability on the interpretation of sensitivity studies in a regional climate model (O'Brien et al.; 2010, Clim. Dyn.) and on the validation of a regional climate model with an updated boundary layer parameterization (O'Brien et al.; 2012, Geophys. Mod. Dev.). 

Model Development

The bulk of Travis' dissertation work involved coupling a new turbulence (boundary layer) parameterization into a regional climate model; he coupled the University of Washington turbulence parameterization into the International Centre for Theoretical Physics's regional climate model, RegCM4.1.    The new turbulence parameterization improves the representation of the physical processes that occur at the tops of stratiform clouds, and it allows RegCM4.1 to develop stratocumulus clouds and coastal fog.  This effort is described in O'Brien et al. (2012, Geophys. Mod. Dev.), Giorgi et al. (2012; Clim. Res.), and  O'Brien et al. (2012, Clim. Dyn.).

Travis currently serves as a volunteer developer on the RegCM development team, and he helps to maintain and develop the University of Washington code in RegCM.

Coastal Fog and California Climate: Model Application

Travis is using RegCM, Community Earth System Model, and various observational datasets to understand how and why California coastal fog has declined over the past century and how fog may change in the future.  So far this research has provided strong evidence that local sea surface temperatures are one of the strongest drivers of year-to-year variability in fog, and that systematic changes in near-coastal circulation (particularly a strengthening of subsidence related to a strengthening of the coastal jet) have driven the decline in fog.  Current efforts involve using a coupled ocean-atmosphere modeling system to understand how changes in near-coastal upwelling may additionally change coastal fog.

Education

• 2008-2011: University of California, Santa Cruz
  Ph. D. Earth Science. Dissertation: The Recent Past and Possible Future Decline of California Coastal Fog
  Advisors: Professor Lisa C. Sloan and Professor Patrick Y. Chuang
• 2006-2008: University of California, Santa Cruz
  M. S. Earth Science. Thesis: How Did Airborne Dust Affect North American Climate During the 1930's Dust Bowl?
  Advisor: Professor Lisa C. Sloan
• 2001-2005: University of California, Santa Cruz
  B. S. Physics. Thesis: Anisotropic Local Distortion of La_1.2Sr_1.8Mn₂O₇ Through the Ferromagnetic Transition Temperature
  Advisor: Professor Frank Bridges

Professional Experience

• 2011-present: Geological Postdoctoral Fellow, Lawrence BerkeleyNational Lab. Advisor: Professor William D. Collins
• 2010: Associate in Atmospheric Sciences, UC Davis
• 2009-2011: Ph.D Candidate, UC Santa Cruz
• 2006-2009: Graduate Student Researcher, UC Santa Cruz
• 2006: Research Consultant, Los Alamos National Laboratory
• 2004-2005: Research Assistant, UC Santa Cruz
• 2004: Student Intern, Stanford Linear Accelerator

Selected Synergistic Activities

• Weekly seminar coorganizer, 2012, LBNL Climate Department
• Session co-convener, AGU Fall Meeting, 2012. A025: Coastal Fog: Atmosphere, Biosphere,Ocean, and Land Interactions
• Session co-convener, AGU Fall Meeting, 2012. A066: Scale Dependence, Scale Invariance, andScale Aware Parameterization
• Participant and Lab Instructor, ICTP RegCM Workshop and Tutorial, 2010 and 2012
• Session co-convener, AGU Fall Meeting, 2010. GC15: Coastal Climates in a Changing World
• Session co-convener, AGU Fall Meeting, 2009. IN11D: Management and Dissemination ofEarth and Space Science Models
• Associate (volunteer) developer, ICTP RegCM
• Participant, 2007 and 2008 Climate Leadership Summit, Santa Cruz, CA

Teaching Experience

• Teaching Assistant, Earth Sciences, 110B, Earth as a Chemical System, UCSC Winter 2011
• Associate in Atmospheric Sciences, Atmospheric Sciences 120, Atmospheric Thermodynamics and Cloud Physics, UCD Fall 2010
• Teaching Assistant, Earth Sciences 80C, Introduction to Weather and Climate, UCSC Fall 2009
• Teaching Assistant Earth Sciences 110B, Earth as a Chemical System, UCSC Winter 2009
• Teaching Assistant Earth Sciences 10, California Geology, UCSC Fall 2007
• Teaching Assistant Earth Sciences 80D, Earth Sciences in the Cinema, UCSC Spring 2007

Current and Past Support

• 06/12 NASA-ROSES PMM 2012, Unfunded
  Investigation into the use of TRMM andGPM data to constrain and develop scale-aware model parameterizations to improve model simulations of extreme precipitation
• 05/11 NSF AGS Postdoctoral Fellowship, Unfunded
  AGS-PRF: Developing and Applying a Model of Coastal Fog During the Last Glacial Maximum
• 09/08 09/10 UCSC STEPS Institute, $1,000
  A New Model for the Future of Fog on California's Coast
• 04/07 - 04/08 UCSC STEPS Institute, $1,500
  A Neural Network Model of Agricultural Response to Local Climate
• 03/07 UCSC CDELSI Institute, $300
  Travel grant to present at AGU Joint Meeting, 2007