sustainedwindduration#
[SustWindDur] = sustainedwindduration(windvel, winddir, MaxwindvelVar, MaxwinddirVar, WindTimeInterval, window_length, dispout)
Description#
Calculate the sustained wind duration
Inputs#
- windvel
Wind velocity time series data in (m/s)
- winddir
Wind direction time series data in (Degree)
- MaxwindvelVar=2.5;
- Maximum allowed wind velocity variation around a mean to allow wind to be considered sustained in (m/s)Coastal Engineering Manual (2015) suggests 2.5 m/s
- MaxwinddirVar=15;
- Maximum allowed wind direction variation around a mean to allow wind to be considered sustained in (Degree)Coastal Engineering Manual (2015) suggests 15 degree
- WindTimeInterval=3600;
- Time interval (time step) between two consecutive wind measurements (data points) in (second)Example: for 60-min measurement interval: WindTimeInterval=3500 (s)
- window_length=7;
Number of data points in sliding window for calculating moving average values, must be odd
- dispout=’no’;
Define to display outputs or not (‘yes’: display, ‘no’: not display)
Outputs#
- SustWindDur
Sustained Wind Duration in (second)
Examples#
%Data from https://tidesandcurrents.noaa.gov for Grand Isle, LA, USA (8761724), for June 1st, 2017, reported hourly
windvel=[3;4.7;4.9;5.3;3.3;3.4;3.3;3.8;3.1;2;1.3;1.2;1.5;3.2;2.9;3;2.9;3.7;3.7;3.1;3.4;2.6;2.5;2.5]; %24 Hour wind velocity
winddir=[78;86;88;107;131;151;163;163;153;150;148;105;105;75;95;103;97;103;108;111;124;183;171;113]; %24 Hour wind direction
[SustWindDur]=sustainedwindduration(windvel,winddir,2.5,15,3600,7,'yes');
References#
U.S. Army Corps of Engineers (2015). Coastal Engineering Manual. Engineer Manual 1110-2-1100, Washington, D.C.: U.S. Army Corps of Engineers.
Yamartino, R. J. (1984). A comparison of several “single-pass” estimators of the standard deviation of wind direction. Journal of Climate and Applied Meteorology, 23(9), 1362-1366.
Change point detection: * https://en.wikipedia.org/wiki/Change_detection * https://en.wikipedia.org/wiki/Step_detection * https://www.mathworks.com/help/signal/ref/findchangepts.html * https://www.mathworks.com/help/matlab/ref/ischange.html * deepcharles/ruptures