ChESS Series: “A Universal Scaling Law for Gas Transfer Velocities Across Complex Interfaces”

 

Gabriel Katul, Professor of Hydrology and Micrometeorology at Duke University, presented, “A Universal Scaling Law for Gas Transfer Velocities Across Complex Interfaces,” at 4:30 p.m. Thursday, March 1, in Maeder Hall, Andlinger Center for Energy and the Environment. This was the fourth event in PEI’s Challenges in Environmental Sciences Seminar (CHESS) Series, and also a Department of Civil and Environmental Engineering Seminar.

Bulk mass exchange between an interface-emitting or -absorbing gas and a turbulent flow — represented by a gas transfer velocity — is commonly described as an empirical function of a mean velocity at some reference height. Such a representation, while of practical significance and continued use in large-scale climate models, misses the most important ingredient to the transfer process itself: turbulent eddies. The connection between energy content in eddies (a microscopic state) and gas transfer velocities (a macroscopic outcome) may be viewed as analogous to a fluctuation-dissipation relation, except for turbulent flows.

ChESS Series: “A Universal Scaling Law for Gas Transfer Velocities Across Complex Interfaces”

Publish Date

March 1, 2018

Presenter(s)

Gabriel Katul

Video Length

01:01:05

 

Gabriel Katul, Professor of Hydrology and Micrometeorology at Duke University, presented, “A Universal Scaling Law for Gas Transfer Velocities Across Complex Interfaces,” at 4:30 p.m. Thursday, March 1, in Maeder Hall, Andlinger Center for Energy and the Environment. This was the fourth event in PEI’s Challenges in Environmental Sciences Seminar (CHESS) Series, and also a Department of Civil and Environmental Engineering Seminar.

Bulk mass exchange between an interface-emitting or -absorbing gas and a turbulent flow — represented by a gas transfer velocity — is commonly described as an empirical function of a mean velocity at some reference height. Such a representation, while of practical significance and continued use in large-scale climate models, misses the most important ingredient to the transfer process itself: turbulent eddies. The connection between energy content in eddies (a microscopic state) and gas transfer velocities (a macroscopic outcome) may be viewed as analogous to a fluctuation-dissipation relation, except for turbulent flows.