Main Title |
Variability of Short Term Eddy-Correlation Estimates of Mass Exchange. |
Author |
Wesely, M. L. ;
Hart, R. L. ;
|
CORP Author |
Argonne National Lab., IL.;Environmental Protection Agency, Research Triangle Park, NC. Atmospheric Sciences Research Lab. |
Year Published |
1985 |
Report Number |
EPA/600/D-85/039; |
Stock Number |
PB85-172641 |
Additional Subjects |
Detectors ;
Transport properties ;
Mass flow ;
Air pollution ;
Turbulent diffusion ;
Sulfur oxides ;
Nitrogen oxides ;
Water vapor ;
Heat ;
Momentum ;
Flux(Rate) ;
Wind velocity ;
Spectroscopic analysis ;
Air pollution detection ;
Numerical solution
|
Holdings |
Library |
Call Number |
Additional Info |
Location |
Last Modified |
Checkout Status |
NTIS |
PB85-172641 |
Some EPA libraries have a fiche copy filed under the call number shown. |
|
07/26/2022 |
|
Collation |
26p |
Abstract |
The signals from sensors used to measure atmospheric scalar fluctuations ordinarily produce characteristic spectra and cospectra with vertical wind velocity that are strongly influenced by vertical transport processes. Unwanted signal noise generated by some of the fast response chemical sensors, however, distort the spectra and cospectra and increase run-to-run variability of eddy-correlation flux estimates. Instead of data collection periods of only 30 min needed to provide a precision of approximately 10-20% in each flux estimate obtained at heights of 5-10 m during ideal daytime conditions, an ensemble derived from several such runs is necessary with certain sensors in order to achieve comparable precision. This has been the practical experiences obtained in numerous experiments above various natural surfaces, and is verified to a limited extent by both empirical and theoretical investigations. |
PUB Date Free Form |
Feb 85 |
Category Codes |
14B; 4B; 68A; 55E |
NTIS Prices |
PC A03/MF A01 |
Primary Description |
600/09 |
Document Type |
NT |
Cataloging Source |
NTIS/MT |
Control Number |
514425597 |
Origin |
NTIS |
Type |
CAT |