Sponsor
Office of Naval Research Grants N00014-13-1-0084 and N00014-10-1-0932 and National Science Foundation Award 1455350 helped fund this research.
Published In
Journal of Atmospheric and Oceanic Technology
Document Type
Article
Publication Date
4-2017
Subjects
Columbia River Estuary (Or. and Wash.), Tidal dynamics, Estuaries -- Remote sensing, Columbia River -- Tidal currents
Abstract
Tides and river slope are fundamental characteristics of estuaries, but they are usually undersampled due to deficiencies in the spatial coverage of water level measurements. This study aims to address this issue by investigating the use of airborne lidar measurements to study tidal statistics and river slope in the Columbia River estuary. Eight plane transects over a 12-h period yield at least eight independent measurements of water level at 2.5-km increments over a 65-km stretch of the estuary. These data are fit to a sinusoidal curve and the results are compared to seven in situ gauges. In situ– and lidar-based tide curves agree to within a root-mean-square error of 0.21 m, and the lidar-based river slope estimate of 1.8 × 10−5 agrees well with the in situ–based estimate of 1.4 × 10−5 (4 mm km−1 difference). Lidar-based amplitude and phase estimates are within 10% and 8°, respectively, of their in situ counterparts throughout most of the estuary. Error analysis suggests that increased measurement accuracy and more transects are required to reduce the errors in estimates of tidal amplitude and phase. However, the results validate the use of airborne remote sensing to measure tides and suggest this approach can be used to systematically study water levels at a spatial density not possible with in situ gauges.
Locate the Document
Definitive version is available online: https://doi.org/10.1175/JTECH-D-16-0197.1
DOI
10.1175/JTECH-D-16-0197.1
Persistent Identifier
http://archives.pdx.edu/ds/psu/21202
Citation Details
Hudson, A.S., S.A. Talke, R. Branch, C. Chickadel, G. Farquharson, and A. Jessup, 2017: Remote Measurements of Tides and River Slope Using an Airborne Lidar Instrument. J. Atmos. Oceanic Technol., 34, 897–904, https://doi.org/10.1175/JTECH-D-16-0197.1
Description
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