Researchers at the University of Miami's Alfred C. Glassell Jr. SUSTAIN Laboratory use a wave and wind simulator "to study the ferocity of a hurricane from the safety of the indoors." (Facebook/Brian McNoldy)

A new wave and wind simulator at the University of Miami hopes to study the ferocity of a hurricane from the safety of the indoors.

The SUrge-STructure-Atmosphere INteraction facility, or SUSTAIN, will help scientists at the Rosenstiel School of Marine and Atmospheric Science better understand the complex interactions between a hurricane and the ocean below it, as well as the coastlines it may affect.

Brian Haus, professor in the Department of Ocean Sciences and lead scientist of the project, observes waves and sea spray as wind speeds are increased in the tank. (Brian McNoldy/University of Miami Rosenstiel School of Marine and Atmospheric Science)

A warm ocean is critical for a hurricane’s survival. Enormous amounts of heat and moisture are transferred from the ocean to the storm, but the rates of those transfers are surprisingly not well-known with much certainty. The frictional drag of the air on the ocean surface over the full spectrum of wind speeds is also a critical relationship to accurately model these storms. Directly measuring the conditions at the air-sea interface under a major hurricane is virtually impossible in nature. But we can get a fairly good idea of what’s going on by utilizing a scale model of the ocean and very intense winds.

A turbulent sea in the periphery of Hurricane Isabel in 2003, as viewed from 200 feet above the ocean surface. Large waves and a layer of sea spray can be seen. At this time and altitude, the aircraft was not near the eyewall, which contains the most intense winds. (Will Drennan/University of Miami Rosenstiel School of Marine and Atmospheric Science)

The huge acrylic and steel tank is 6.5 feet deep, 20 feet wide and 75 feet long. It holds 38,000 gallons of seawater and can contain the fury of an intense hurricane. It’s the largest such laboratory in the world. A large fan can produce winds up to 145 mph at 20 inches above the water’s surface. Taking into account the logarithmic decay of wind speeds near the air-sea interface, that scales to a wind speed of about 215 mph at the standard wind measurement height of 10 meters (33 feet) — a very powerful Category 5 hurricane on the Saffir-Simpson scale.

In addition to the wind, a series of 12 independently controlled wave paddles allow for the generation of a realistic ocean surface with complex swell patterns.

A graph of the vertical profile of wind speed over the lowest 33 feet above the ocean surface tuned to the strongest winds the SUSTAIN facility can create. A wind speed of 145 mph at 20 inches above the surface (red dot) scales to a wind speed of 215 mph at the standard measurement height of 33 feet (green dot). A Category 5 hurricane has wind speeds of at least 155 mph, so SUSTAIN is capable of producing winds representative of any realistic hurricane. (Brian McNoldy/University of Miami Rosenstiel School of Marine and Atmospheric Science)

SUSTAIN addresses a significant gap in the existing research infrastructure available to support the development of disaster resistant and resilient coastal communities. This laboratory provides an innovative experimental test bed to enhance the development of high-resolution coupled wind-wave-surge forecast models as well as computational fluid dynamics models for hurricane impacts on coastal structures.

The Glassell Family Foundation generously provided support for the Alfred C. Glassell Jr. SUSTAIN research facility, and the University of Miami was awarded a $15 million competitive grant from the National Institute of Standards and Technology (NIST), which is funded by the American Recovery and Reinvestment Act (ARRA). In addition to the Glassell Family Foundation, generous gifts from the Marta Weeks Family and the G. Unger Vetlesen Foundation have made the completion of the building possible. Suffolk Construction built the complex.

Brian McNoldy is a senior research associate at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science.