Wind Speed (magnitude) = sqrt ( u * u + v * v ) Oceanographers describe the wind in the direction that it’s flowing towards and meteorologist describes wind in the direction that it’s flowing from. Also keep in mind that wind direction is described differently for oceanography and meteorology. See this wind direction quick reference for calculating wind direction and speed and other tips. But first, you’ll need to do some calculations. This section will show you how to do that. shapefile) and use arrows to show the wind speed and direction (wind vectors). So, what if you have raster(s) containing the u (eastward x-axis) and v (northward y-axis) components and you want to convert to a point layer (e.g. These are the parameters I used to query the data, which can be saved to a URL and shared for downloading: To use the same dataset for this tutorial, click this link: Direct Data Download.Ĭonverting raster wind vector to a point layer with u, v, speed and direction The data set I’m using is the Regional Ocean Modeling System for the main Hawaiian Islands. To download the exact data I used here, you can click the direct data download link below, or use your own data. I am using the PacIOOS ERDAP (Environmental Research Division's Data Access Program) server to download my data. These data or variables can be mapped through time (a dimension) in GIS by making a layer from the netCDF file. It stands for network Common Data Form and is a file format for storing multi-dimensional scientific data,such as temperature, salinity, wind speed and direction. Wind data in netCDF format - you can download the sample below or use your ownĬrayfish plugin for QGIS - if you want to do animation, otherwise it’s optionalįor those who are not familiar with the netCDF format. QGIS software installed - (I’m using version 3.14 on Windows OS) What you’ll need if you want to follow along with this short tutorial. I used their GeoServer services all the time for my tutorials. Check them out for some awesome oceanographic data that are open and very accessible. This is written for my friend, Jim at PacIOOS. speed/magnitude and direction) and create an animation using QGIS. Good luck.This posting is on how to map wind vector (i.e. A small caveat here, I just back of the enveloped this so the code may have problems, I did not compile or test it, this is just a starting point. You will, of course, need to provide the full path to the FFMPEG executable on line 19. exe from the command line with the path to the input and output files minus the extensions, a la:Ĭ:\>ConvertMP3ToMP4.exe C:\Videos\Aqua\BarbieGirl C:\Music\Aqua\BarbiGirl Using FFMPEG you could do something like this: using System į = false į = true į = true į = true į = true į = "//path/to/ffmpeg" į = " -i " + inputFile + " -vn -f mp3 -ab 320k output " + outputFile į()
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