How do waves form? New research provides insights

Researchers conducted a first-of-its-kind study to understand how waves form and increase in windy and hurricane conditions.
The study used high-resolution measurements to analyze air pressure, airflow, and water elevation, capturing up to 1,000 data points per second.
The researchers found that wind speed alone can be used to estimate wind pressure and predict wave growth, marking a significant step in understanding air-sea momentum transfer.
Traditional models of airflow over water underestimate momentum transfer by more than 30% when airflow separates on the leeward side of waves, highlighting the need for refinements to numerical wave models.
The study’s findings can help improve weather forecasting and coastal resilience by providing new insights into how winds interact with the ocean in extreme weather conditions.

A green and blue wave curls over itself as it heads toward shore.

Scientists conducted a first-of-its-kind study into how waves form and increase in windy and hurricane conditions.

The research, which reconstructs the two-dimensional profile of pressure and airflow above wavy surfaces, provides new insights into understanding ocean wave growth and its broader implications for weather forecasting and coastal resilience.

The research team simultaneously measured air pressure, airflow, and water elevation in a controlled environment, capturing up to 1,000 data points per second.

By analyzing these data, they studied how different factors—such as wave height, wave frequency, and wind force—affect the movement of air and the transfer of momentum between the air and the ocean’s surface.

The aim of the study is to understand how waves develop and how winds interact with the ocean in extreme weather conditions.

Building on these high-resolution measurements, the researchers used a wind-wave tank, which is capable of simulating Category 5 hurricane-force winds, to reconstruct the airflow patterns that drive wave growth in strong winds. By employing Constant Temperature Anemometry to capture rapid airflow changes, Particle Image Velocimetry to track the movement of air and water, and Multi-beam Imaging to map wave structures, they gained deeper insights into the dynamic interactions shaping ocean waves.

“Wind pressure acts like fuel for ocean waves—higher pressure pushes on the front of a wave, making it grow taller and move faster,” says Peisen Tan, the lead author of the study and a recent PhD graduate of the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science.

“Measuring the pressure over the open ocean is extremely challenging. Our research… allowed us to document that wind speed alone can be used to estimate this pressure and predict wave growth.”

The researchers found that the traditional models (where the airflow adheres to the water) correctly predict over 90% of momentum transfer in airflow over water until separation occurs. However, when airflow separates on the leeward side of waves (blocked from the wind), these models underestimate momentum transfer by more than 30%.

“This study marks a significant step in understanding air-sea momentum transfer,” says Brian Haus, a professor in the ocean sciences department at the Rosenstiel School and a coauthor of the study.

“Our experimental approach reconstructed the two-dimensional profile of pressure and airflow above wavy surfaces—an achievement that, to our knowledge, is a first-of-its-kind breakthrough. These insights can help refine numerical wave models by incorporating airflow separation effects.”

The study appears in the American Geophysical Union’s Journal of Geophysical Research: Oceans.

Funding for the study was provided in part by the Office of Naval Research.

Source: University of Miami

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Q. What was the main goal of the research study on how waves form?

A. The aim of the study is to understand how waves develop and how winds interact with the ocean in extreme weather conditions.

Q. How did the researchers measure air pressure, airflow, and water elevation in their study?

A. They used a combination of instruments, including Constant Temperature Anemometry, Particle Image Velocimetry, and Multi-beam Imaging, to capture rapid airflow changes and track the movement of air and water.

Q. What is the significance of wind pressure in forming ocean waves?

A. Wind pressure acts like fuel for ocean waves, pushing on the front of a wave and making it grow taller and move faster.

Q. How accurate are traditional models in predicting momentum transfer in airflow over water?

A. The researchers found that traditional models correctly predict over 90% of momentum transfer until separation occurs, but underestimate it by more than 30% when airflow separates on the leeward side of waves.

Q. What is a significant breakthrough achieved by the researchers in their study?

A. They reconstructed the two-dimensional profile of pressure and airflow above wavy surfaces, an achievement that is considered a first-of-its-kind breakthrough.

Q. How can this research help refine numerical wave models?

A. The insights gained from this study can be used to incorporate airflow separation effects into numerical wave models, leading to more accurate predictions of ocean wave growth.

Q. What was the funding source for the research study?

A. Funding for the study was provided in part by the Office of Naval Research.

Q. How did the researchers use a wind-wave tank to simulate extreme weather conditions?

A. They used a wind-wave tank capable of simulating Category 5 hurricane-force winds to reconstruct airflow patterns that drive wave growth in strong winds.

Q. What is the potential impact of this research on coastal resilience and weather forecasting?

A. The study provides new insights into understanding ocean wave growth, which can help improve weather forecasting and coastal resilience by providing more accurate predictions of extreme weather events.