{
  "cells": [
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "\n# Relative and absolute wind\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "from datetime import timedelta\nfrom opendrift.readers import reader_netCDF_CF_generic\nfrom opendrift.models.oceandrift import OceanDrift\n\no = OceanDrift(loglevel=20)  # Set loglevel to 0 for debug information\n\n# Arome\nreader_arome = reader_netCDF_CF_generic.Reader(o.test_data_folder() +\n    '16Nov2015_NorKyst_z_surface/arome_subset_16Nov2015.nc')\n#reader_arome = reader_netCDF_CF_generic.Reader('https://thredds.met.no/thredds/dodsC/mepslatest/meps_lagged_6_h_latest_2_5km_latest.nc')\n\n# Norkyst\nreader_norkyst = reader_netCDF_CF_generic.Reader(o.test_data_folder() +\n    '16Nov2015_NorKyst_z_surface/norkyst800_subset_16Nov2015.nc')\n#reader_norkyst = reader_netCDF_CF_generic.Reader('https://thredds.met.no/thredds/dodsC/sea/norkyst800m/1h/aggregate_be')\n\no.add_reader([reader_norkyst, reader_arome])"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Seeding some particles\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "lon = 4.2; lat = 60.0; # Outside Bergen\ntime = [reader_arome.start_time,\n        reader_arome.start_time + timedelta(hours=30)]"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Using windspeed relative to moving ocean (current)\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "o.set_config('drift:relative_wind',  False)\no.set_config('drift:vertical_mixing', False)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Seed oil elements at defined position and time\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "o.seed_elements(lon, lat, radius=50, number=5000, time=time)\n\no.run(steps=48*2, time_step=1800, time_step_output=3600*2)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Second run, for comparison\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "o2 = OceanDrift(loglevel=20)  # Set loglevel to 0 for debug information\no2.add_reader([reader_norkyst, reader_arome])\no2.set_config('drift:relative_wind',  True)\no2.set_config('drift:vertical_mixing', False)\no2.seed_elements(lon, lat, radius=50, number=5000, time=time)\no2.run(steps=48*2, time_step=1800, time_step_output=3600*2)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Animate and compare the two runs\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "o.animation(compare=o2, legend=['Absolute wind', 'Relative wind'])"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "<img src=\"file://gallery/animations/example_relative_0.gif\">\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "o.plot(compare=o2, legend=['Absolute wind', 'Relative wind'], fast=True)"
      ]
    }
  ],
  "metadata": {
    "kernelspec": {
      "display_name": "Python 3",
      "language": "python",
      "name": "python3"
    },
    "language_info": {
      "codemirror_mode": {
        "name": "ipython",
        "version": 3
      },
      "file_extension": ".py",
      "mimetype": "text/x-python",
      "name": "python",
      "nbconvert_exporter": "python",
      "pygments_lexer": "ipython3",
      "version": "3.11.6"
    }
  },
  "nbformat": 4,
  "nbformat_minor": 0
}