Lucas Harris’s Homepage – Geophysical Fluid Dynamics Laboratory

Lucas Harris

Physical Scientist

Deputy Division Leader, Weather and Climate Dynamics Division

NOAA/Geophysical Fluid Dynamics Laboratory

My research is focused on the development of the algorithms and software within the GFDL Finite-Volume Cubed-Sphere Dynamical Core, FV3, and its applications in the comprehensive weather and climate models fvGFS, HiRAM, and the next-generation AM4.

My personal expertise is on grid refinement techniques. The two methods for doing this in FV3 are grid nesting and grid stretching. These techniques allow FV3-powered models to be run at a very high resolution over a limited area convection-resolving forecasting, seasonal prediction, and regional climate modeling. Here is an introduction to variable-resolution techniques. Currently our group is using grid nesting and grid stretching to develop global models suitable for storm-scale severe thunderstorm and hurricane forecasting, and for subseasonal prediction of intense hurricanes.

Recent presentations:

I have given a semi-technical introduction for non-specialists, entitled “FV3: The Present and Future of Weather and Climate Modeling”, most recently for the 2017 NOAA Science Days. The slides can be seen here, and the recording of the public media briefing is also available (my segment starts at about 20:40).
A brief technical introduction to FV3 was given for DCMIP 2016.
A longer technical presentation of the solver and of grid refinement in FV3 have been given, most recently in June 2018.
In May 2017, GFDL was represented for the first time at the Hazardous Weather Testbed’s Spring Forecasting Experiment. Five-day forecasts from our global-to-3-km nested fvGFS were submitted to HWT for evaluation, which is forthcoming. A presentation summarizing our own analysis of the results was given as an NGGPS virtual seminar. Results from the 2018 experiment are being processed.

Other projects and documents

I have written a simple but efficient and highly flexible feature tracker, primarily for tropical and extratropical cyclones. Email me if you would like further information.

I have a few nice GrADS scripts, along with examples, that I use for some of my work that others may find helpful.

Ray Pierrehumbert’s classic essay on mountain gravity-wave drag parameterization is difficult to find online. A copy is available at ECMWF. (Many other excellent ECMWF conference proceedings, including many classic contributions by GFDL scientists, are available as well.) A conference proceeding describing the use of the Pierrehumbert and Wyman scheme in the Miyakoda GFDL model, also hard to find, is available here.

My colleague Xi Chen and I have submitted a comment on an article about grid staggering.

Publications

Harris, Lucas M., Matthew Morin, Shannon Rees, Linjiong Zhou, and William Stern: Explicit nested-grid prediction of convective-scale motions in a skillful global model. Submitted to J. Geophys. Res. Manuscript Supplemental information
Harris, Lucas M., Shian-Jiann Lin, and C-Y Tu, June 2016: High resolution climate simulations using GFDL HiRAM with a stretched global grid. Journal of Climate, 29(11), DOI:10.1175/JCLI-D-15-0389.1
Scott, R K., Lucas M Harris, and L M Polvani, January 2016: A test case for the inviscid shallow water equations on the sphere. Quarterly Journal of the Royal Meteorological Society, 142(694), DOI:10.1002/qj.2667
Zhang, Wei, Gabriel A Vecchi, Hiroyuki Murakami, Thomas L Delworth, Andrew T Wittenberg, Anthony Rosati, Seth D Underwood, Whit G Anderson, Lucas M Harris, Richard G Gudgel, Shian-Jiann Lin, G Villarini, and Jan-Huey Chen, February 2016: Improved Simulation of Tropical Cyclone Responses to ENSO in the Western North Pacific in the High-Resolution GFDL HiFLOR Coupled Climate Model. Journal of Climate, 29(4), DOI:10.1175/JCLI-D-15-0475.1
Fan, Song-Miao, Lucas M Harris, and Larry W Horowitz, November 2015: Atmospheric energy transport to the Arctic 1979-2012. Tellus A, 67, DOI:10.3402/tellusa.v67.25482
Murakami, Hiroyuki, Gabriel A Vecchi, Seth D Underwood, Thomas L Delworth, Andrew T Wittenberg, Whit G Anderson, Jan-Huey Chen, Richard G Gudgel, Lucas M Harris, Shian-Jiann Lin, and Fanrong Zeng, December 2015: Simulation and Prediction of Category 4 and 5 Hurricanes in the High-Resolution GFDL HiFLOR Coupled Climate Model. Journal of Climate, 28(23), DOI:10.1175/JCLI-D-15-0216.1
Xiang, Baoqiang, Shian-Jiann Lin, Ming Zhao, Gabriel A Vecchi, T Li, X Jiang, Lucas M Harris, and Jan-Huey Chen, February 2015: Beyond weather time scale prediction for Hurricane Sandy and Super Typhoon Haiyan in a global climate model. Monthly Weather Review, 143(2), DOI:10.1175/MWR-D-14-00227.1
Harris, L.M. and S.-J. Lin, July 2014: Global-to-regional nested-grid climate simulations in the GFDL High Resolution Atmosphere Model. Journal of Climate, 27(13), DOI:10.1175/JCLI-D-13-00596.1.
Harris, L.M. and S-J. Lin, 2012: A two-way nested global-regional dynamical core on the cubed-sphere grid. Mon. Wea. Rev.: 141(1), doi:10.1175/MWR-D-11-00201.1.
Harris, L.M, P.H. Lauritzen, and R. Mittal, 2010: A flux-form version of the conservative semi-Lagrangian multi-tracer transport scheme (CSLAM) on the cubed sphere grid. Journal of Computational Physics, 230(4), DOI:10.1016/j.jcp.2010.11.001.
Harris, L.M. and D.R. Durran, 2010: An idealized comparison of one-way and two-way grid nesting. Mon. Wea. Rev., 138, 2174–2187, DOI:10.1175/2010MWR3080.1
Harris, L.M. and V. R. Kotamarthi, 2005: The Characteristics of the Chicago Lake Breeze and Its Effects on Trace
Particle Transport: Results from an Episodic Event Simulation. J. Appl. Meteor., 44, 1637–1654, DOI:10.1175/JAM2301.1