Global assessment of semidiurnal internal tide aliasing in Argo profiles

TitleGlobal assessment of semidiurnal internal tide aliasing in Argo profiles
Publication TypeJournal Article
Year of Publication2019
AuthorsHennon T.D, Alford MH, Zhao Z.X
Volume49
Pagination2523-2533
Date Published2019/10
Type of ArticleArticle
ISBN Number0022-3670
Accession NumberWOS:000487072800003
Keywordsabyssal; altimetry; Energy flux; floats; heat; In situ oceanic observations; oceanic; oceanography; oxygen; Profilers; propagation; salinity; southern-ocean; waves; wind
Abstract

Though unresolved by Argo floats, internal waves still impart an aliased signal onto their profile measurements. Recent studies have yielded nearly global characterization of several constituents of the stationary internal tides. Using this new information in conjunction with thousands of floats, we quantify the influence of the stationary, mode-1 M-2 and S-2 internal tides on Argo-observed temperature. We calculate the in situ temperature anomaly observed by Argo floats (usually on the order of 0.1 degrees C) and compare it to the anomaly expected from the stationary internal tides derived from altimetry. Globally, there is a small, positive correlation between the expected and in situ signals. There is a stronger relationship in regions with more intense internal waves, as well as at depths near the nominal mode-1 maximum. However, we are unable to use this relationship to remove significant variance from the in situ observations. This is somewhat surprising, given that the magnitude of the altimetry-derived signal is often on a similar scale to the in situ signal, and points toward a greater importance of the nonstationary internal tides than previously assumed.

DOI10.1175/jpo-d-19-0121.1
Student Publication: 
No