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Turbulence and Gas Transfer Velocities in Sheltered Flooded Forests of the Amazon Basin
Author(s) -
MacIntyre Sally,
Fernandes Amaral Joao H.,
Barbosa Pedro M.,
Cortés Alicia,
Forsberg Bruce R.,
Melack John M.
Publication year - 2019
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl083948
Subject(s) - turbulence , turbulence kinetic energy , environmental science , atmospheric sciences , buoyancy , energy budget , convection , dissipation , wind speed , meteorology , hydrology (agriculture) , mechanics , geology , physics , thermodynamics , geotechnical engineering
Seasonally flooded forests along tropical rivers cover extensive areas, yet the processes driving air‐water exchanges of radiatively active gases are uncertain. To quantify the controls on gas transfer velocities, we combined measurements of water‐column temperature, meteorology in the forest and adjacent open water, turbulence with an acoustic Doppler velocimeter, gas concentrations, and fluxes with floating chambers. Under cooling, measured turbulence, quantified as the rate of dissipation of turbulent kinetic energy ( ε ), was similar to buoyancy flux computed from the surface energy budget, indicating convection dominated turbulence production. Under heating, turbulence was suppressed unless winds in the adjacent open water exceeded 1 m/s. Gas transfer velocities obtained from chamber measurements ranged from 1 to 5 cm/hr and were similar to or slightly less than predicted using a turbulence‐based surface renewal model computed with measured ε and ε predicted from wind and cooling.