{
  "cells": [
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "\n# Leeway\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "from datetime import timedelta\nimport cmocean\nimport xarray as xr\nimport trajan as ta\nfrom opendrift import test_data_folder as tdf\nfrom opendrift.readers import reader_netCDF_CF_generic\nfrom opendrift.models.leeway import Leeway\n\no = Leeway(loglevel=0)  # Set loglevel to 0 for debug information\n\n# Atmospheric model for wind\n#reader_arome = reader_netCDF_CF_generic.Reader('https://thredds.met.no/thredds/dodsC/mepslatest/meps_lagged_6_h_latest_2_5km_latest.nc')\nreader_arome = reader_netCDF_CF_generic.Reader(tdf +\n    '16Nov2015_NorKyst_z_surface/arome_subset_16Nov2015.nc')\n\n# Ocean model for current\n#reader_norkyst = reader_netCDF_CF_generic.Reader('https://thredds.met.no/thredds/dodsC/mepslatest/meps_lagged_6_h_latest_2_5km_latest.nc')\nreader_norkyst = reader_netCDF_CF_generic.Reader(tdf +\n    '16Nov2015_NorKyst_z_surface/norkyst800_subset_16Nov2015.nc')\n\no.add_reader(reader_norkyst)\no.add_reader(reader_arome)\no.set_config('environment:fallback:x_sea_water_velocity', 0)\no.set_config('environment:fallback:y_sea_water_velocity', 0)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Seed leeway elements at defined position and time\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "object_type = 26  # 26 = Life-raft, no ballast\no.seed_elements(lon=4.5, lat=59.6, radius=100, number=1000,\n                time=reader_arome.start_time, object_type=object_type)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Running model\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "ds = o.run(duration=timedelta(hours=48), time_step=1800, time_step_output=3600)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Print and plot results\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "print(o)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Animation with current as background.\nNote that drift is also depending on wind, which is not shown.\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "o.animation(background=['x_sea_water_velocity', 'y_sea_water_velocity'],\n             skip=5,  # show every 5th vector\n             cmap=cmocean.cm.speed, vmin=0, vmax=.8, bgalpha=.7, land_color='#666666', fast=True)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "<img src=\"file://gallery/animations/example_leeway_0.gif\">\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "o.plot(fast=True)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "Plot density of stranded elements\n\n"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "collapsed": false
      },
      "outputs": [],
      "source": [
        "ds_stranded = ds.where(ds.status==1)\ngrid = ds_stranded.traj.make_grid(dx=3000)\nds_conc = ds_stranded.traj.concentration(grid).sum(dim='time')\no.plot(fast=True, background=ds_conc.number.where(ds_conc.number>0),\n       cmap=cmocean.cm.thermal, clabel='Density of stranded elements',\n       show_elements=False, linewidth=0)"
      ]
    }
  ],
  "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": "3.14.3"
    }
  },
  "nbformat": 4,
  "nbformat_minor": 0
}