Abstract
Surfacewind stress is a crucial driver of upper-ocean processes, impacting air-sea gas flux,wind-wave development, andmaterial transport.Conventional eddy covariance (EC)processing requires imposing a fixed averagingwindow on thewind velocity time series in order to estimate the downward flux of momentum.While this method has become the standard means of directlymeasuring the wind stress, the use of a fixed averaging interval inherently constrains one's ability to resolve transient signals that may have net effects on the air-sea interactions. Here we utilize the wavelet transform to develop a new technique for directly quantifying thewind stressmagnitude fromthewavelet coscalogram products.The time averages of these products evaluated at the scale ofmaximumamplitude are highly correlatedwith the EC estimates (R2 5 0.99; 5-min time windows), suggesting that stress is particularly sensitive to the dominant turbulent eddies. By taking advantage of the new method's high temporal resolution, transient wind forcing and its dominant scales may be explicitly computed and analyzed. This technique will allow for more general investigations into air-sea dynamics under nonstationary or spatially inhomogeneous conditions, such aswithin the nearshore region.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1849-1863 |
| Number of pages | 15 |
| Journal | Journal of Atmospheric and Oceanic Technology |
| Volume | 35 |
| Issue number | 9 |
| DOIs | |
| State | Published - Jan 1 2018 |
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Keywords
- Air-sea interaction
- Coastal meteorology
- Wavelets
- Wind waves
ASJC Scopus subject areas
- Ocean Engineering
- Atmospheric Science
Cite this
Quantifying highly variable air-sea momentum flux using wavelet analysis. / Laxague, Nathan J.M.; Haus, Brian K.; Ortiz-Suslow, David G.; Graber, Hans C.
In: Journal of Atmospheric and Oceanic Technology, Vol. 35, No. 9, 01.01.2018, p. 1849-1863.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Quantifying highly variable air-sea momentum flux using wavelet analysis
AU - Laxague, Nathan J.M.
AU - Haus, Brian K.
AU - Ortiz-Suslow, David G.
AU - Graber, Hans C.
PY - 2018/1/1
Y1 - 2018/1/1
N2 - Surfacewind stress is a crucial driver of upper-ocean processes, impacting air-sea gas flux,wind-wave development, andmaterial transport.Conventional eddy covariance (EC)processing requires imposing a fixed averagingwindow on thewind velocity time series in order to estimate the downward flux of momentum.While this method has become the standard means of directlymeasuring the wind stress, the use of a fixed averaging interval inherently constrains one's ability to resolve transient signals that may have net effects on the air-sea interactions. Here we utilize the wavelet transform to develop a new technique for directly quantifying thewind stressmagnitude fromthewavelet coscalogram products.The time averages of these products evaluated at the scale ofmaximumamplitude are highly correlatedwith the EC estimates (R2 5 0.99; 5-min time windows), suggesting that stress is particularly sensitive to the dominant turbulent eddies. By taking advantage of the new method's high temporal resolution, transient wind forcing and its dominant scales may be explicitly computed and analyzed. This technique will allow for more general investigations into air-sea dynamics under nonstationary or spatially inhomogeneous conditions, such aswithin the nearshore region.
AB - Surfacewind stress is a crucial driver of upper-ocean processes, impacting air-sea gas flux,wind-wave development, andmaterial transport.Conventional eddy covariance (EC)processing requires imposing a fixed averagingwindow on thewind velocity time series in order to estimate the downward flux of momentum.While this method has become the standard means of directlymeasuring the wind stress, the use of a fixed averaging interval inherently constrains one's ability to resolve transient signals that may have net effects on the air-sea interactions. Here we utilize the wavelet transform to develop a new technique for directly quantifying thewind stressmagnitude fromthewavelet coscalogram products.The time averages of these products evaluated at the scale ofmaximumamplitude are highly correlatedwith the EC estimates (R2 5 0.99; 5-min time windows), suggesting that stress is particularly sensitive to the dominant turbulent eddies. By taking advantage of the new method's high temporal resolution, transient wind forcing and its dominant scales may be explicitly computed and analyzed. This technique will allow for more general investigations into air-sea dynamics under nonstationary or spatially inhomogeneous conditions, such aswithin the nearshore region.
KW - Air-sea interaction
KW - Coastal meteorology
KW - Wavelets
KW - Wind waves
UR - http://www.scopus.com/inward/record.url?scp=85062151187&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85062151187&partnerID=8YFLogxK
U2 - 10.1175/JTECH-D-18-0064.1
DO - 10.1175/JTECH-D-18-0064.1
M3 - Article
AN - SCOPUS:85062151187
VL - 35
SP - 1849
EP - 1863
JO - Journal of Atmospheric and Oceanic Technology
JF - Journal of Atmospheric and Oceanic Technology
SN - 0739-0572
IS - 9
ER -