Session 6 Downscaling Models (Parcel Scale)—Atmosphere, Land, and Ocean

Tuesday, 14 January 2020: 1:30 PM-2:30 PM
158 (Boston Convention and Exhibition Center)
Host: 18th Symposium on the Coastal Environment
Cochairs:
Alan Blumberg, Stevens Institute of Technology, Davidson Laboratory, Hoboken, NJ and Art Miller, NOAA, NOS CO-OPS, Silver Spring, MD

How best to adequately represent small-scale atmosphere motion in the range of scales of the order of 100 meters and less based on Numerical Model output, remains a topic of debate. Several methods need to be investigated with a goal to identify an optimal approach to reproduce realistic near-surface flow fields between the range of 50 meter to 100 meters resolution scale via dynamic downscaling or statistical methods.

Why we need a Downscaling? One of the major hurricane threats is damaging winds. Sustained winds and gusts of hurricanes have proved to be catastrophic for many homes. Most of the damage caused by hurricane winds occurs within the first few hours during a hurricane’s landfall. Hurricane Michael (2018), Harvey (2018), Irma (2017) some of the recent hurricanes cased huge damages across the coastal areas. We need downscaling discussion (not only hurricane but other application as well) to reach out knowledge at meter scale and link its application to the society. With our current and possible future computing powers, we are ready to deliver at 10-100 meters scale applications that will directly connect to the society (LINKS).  

The wind gust generated by large transient eddies are the most likely culprits for producing damage patterns of a few hundred meter in scale or even smaller (Ping Zhu 2008). The coastal hurricane wind damage is determined by various building design codes but at the same time we need to improve our understanding on fine-scale structure of damaging winds.Understanding the wind dynamics of landfalling hurricanes and predicting wind changes at or near the time of landfall are of vital importance, not only for scientific study of land- falling hurricanes, but also for hurricane preparation and assessment of hurricane damage and financial losses in the landfall regions. However, the detailed structure and change of surface winds during landfall, which is controlled by the multi-scale interactions among the storm-scale circulation, meso-vortices, turbulence-scale eddies, and the underlying surface, cannot be obtained from operational numerical simulations (Ping Zhu 2008). 

In our downscaling session, we want people from different background and addressing the challenges in the downscaling techniques for many applications such as landfall cyclone damages in the coastal areas, downscaling flash flood forecasting & reconstruction, applications of using fine scale (at meters resolution) landuse/landcover along with topography, Build Large Eddy Simulation (LES) framework for fine parcel-scale applications (Dynamic downscaling), Statistical downscaling.

The Idea of downscaling session is a good fit to the AMS 2020 Theme as this downscaling session bring greater knowledge of the situation to more positive impact on society (LINKS).

  1. Zhu, P., 2008: Simulation and parameterization of the turbulent transport in the hurricane boundary layer by large eddies. J. Geophys. Res., 113, D17104

Papers:
1:30 PM
6.1
The Wind Downscaling Modeling Framework for NOAA’s Coastal-Act Project
Anil Kumar, NOAA, College Park, MD; and A. Mehra, G. DiMego, A. Chawla, M. Zaizhong, J. Kain, A. Vanderwesthuysen, S. Moghimi, E. Myers III, and S. V. Vinogradov
1:45 PM
6.2
Improved Wind Turbine Parameterizations in LES of Large Wind Farms Using Vorticity Dynamics
Carl R. Shapiro, The Johns Hopkins Univ., Baltimore, MD; and D. F. Gayme and C. Meneveau
2:00 PM
6.3
Large Eddy Simulation of an Entire Tropical Cyclone
Junsi Ito, Atmosphere and Ocean Research Institute, The Univ. of Tokyo, Kashiwa, Chiba, Japan; and H. Niino and T. Oizumi
2:15 PM
6.4
Challenges for Mesoscale Numerical Models in the Littoral Environment
David D. Flagg, NRL, Monterey, CA; and J. D. Doyle, B. K. Haus, H. C. Graber, J. H. MacMahan, D. G. Ortiz-Suslow, L. Shen, Q. Wang, N. J. Williams, and R. Beach
- Indicates paper has been withdrawn from meeting
- Indicates an Award Winner