@misc{10481/67220,
year = {2021},
month = {2},
url = {http://hdl.handle.net/10481/67220},
abstract = {An analysis based on the law of linear momentum conservation demonstrates unequivocally
that the mass fraction is the scalar whose gradient determines gas diffusion, both
molecular and turbulent. It illustrates sizeable errors in previous micrometeorological definitions
of the turbulent gas flux based on fluctuations in other scalars such as the mixing
ratio or density. In deference to conservation law, we put forth a new definition for the turbulent
gas flux. Net gas transport is then defined as the sum of this turbulent flux with systematic
transport by the mean flow. This latter, non-diffusive flux is due to the net upward
boundary-layer momentum, a Stefan flow forced by evaporation, which is the dominant
surface gas exchange. A comparison with the traditional methodology shows exact agreement
between the two methods regarding the net flux, but with the novelty of partitioning
gas transport according to distinct physical mechanisms. The non-diffusive flux is seen to
be non-negligible in general, and to dominate turbulent transport under certain conditions,
with broad implications for boundary-layer meteorology.},
organization = {Spanish Ministry of Economy project ELEMENTAL 

CGL2017-83538-C3-1-R},
organization = {Andalusian government 

P18-RT-3629},
organization = {European Commission},
publisher = {Springer},
keywords = {Conservation of linear momentum},
keywords = {Eddy covariance},
keywords = {Reynolds averaging},
keywords = {Systematic transport},
keywords = {WPL density corrections},
title = {Disentangling Turbulent Gas Diffusion from Non‑diffusive Transport in the Boundary Layer},
doi = {10.1007/s10546-021-00605-5},
author = {Kowalski, Andrew and Serrano Ortiz, Penélope and Miranda García, Gabriela and Fratini, Gerardo},
}