 |
| Titel |
Determining water sources in the boundary layer from tall tower profiles of water vapor and surface water isotope ratios after a snowstorm in Colorado |
| VerfasserIn |
D. Noone, C. Risi, A. Bailey, M. Berkelhammer, D. P. Brown, N. Buenning, S. Gregory, J. Nusbaumer, D. Schneider, J. Sykes, B. Vanderwende, J. Wong, Y. Meillier, D. Wolfe |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 13, no. 3 ; Nr. 13, no. 3 (2013-02-08), S.1607-1623 |
| Datensatznummer |
250017650
|
| Publikation (Nr.) |
 copernicus.org/acp-13-1607-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| The D/H isotope ratio is used to attribute boundary layer humidity changes to
the set of contributing fluxes for a case following a snowstorm in which a
snow pack of about 10 cm vanished. Profiles of H2O and CO2 mixing
ratio, D/H isotope ratio, and several thermodynamic properties were measured
from the surface to 300 m every 15 min during four winter days near
Boulder, Colorado. Coeval analysis of the D/H ratios and CO2
concentrations find these two variables to be complementary with the former
being sensitive to daytime surface fluxes and the latter particularly
indicative of nocturnal surface sources. Together they capture evidence for
strong vertical mixing during the day, weaker mixing by turbulent bursts and
low level jets within the nocturnal stable boundary layer during the night,
and frost formation in the morning. The profiles are generally not well
described with a gradient mixing line analysis because D/H ratios of the end
members (i.e., surface fluxes and the free troposphere) evolve throughout the
day which leads to large uncertainties in the estimate of the D/H ratio of
surface water flux. A mass balance model is constructed for the snow pack,
and constrained with observations to provide an optimal estimate of the
partitioning of the surface water flux into contributions from sublimation,
evaporation of melt water in the snow and evaporation from ponds. Results
show that while vapor measurements are important in constraining surface
fluxes, measurements of the source reservoirs (soil water, snow pack and
standing liquid) offer stronger constraint on the surface water balance.
Measurements of surface water are therefore essential in developing
observational programs that seek to use isotopic data for flux attribution. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|