Animation of the Amazon Fires 2019 using Google Earth Engine

Let’s use Google Earth Engine and satellite data to visualize the time-series of the Amazon Fires 2019. In this post, I will be using FIRMS (Fire Information for Resource Management System). FIRMS disseminates Near-Real-Time active fire from the NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) and NASA’s Visible Infrared Imaging Radiometer Suite (VIIRS) satellite. This data is available in Google Earth Engine (GEE) as ee.ImageCollection('FIRMS'). In 2019, Amazon caught up in fire throughout the year. In this post, I will animate through August. But feel free to change the dates as you want. It might take some time for the animation to be prepared if you have many days. If it shows Page Unresponsive just wait some times before it is ready.
Use the code below or follow this link.

var firms = ee.ImageCollection('FIRMS');

var countries = ee.FeatureCollection('ft:1tdSwUL7MVpOauSgRzqVTOwdfy17KDbw-1d9omPw');
var geometry = countries.filter(ee.Filter.inList('Country', ['Brazil'])).geometry().bounds();
Map.centerObject(geometry, 6);

firms = firms.filterBounds(geometry).filterDate('2019-08-01', '2019-08-31').sort('system:time_start', false);

var visualizeFirms = function (img) {
  return img.clip(geometry).visualize({
    bands: 'T21',
    min: 325.0,
    max: 400.0,
    palette: ['red', 'orange', 'yellow']
  }).copyProperties(img, img.propertyNames());
};

firms = firms.map(visualizeFirms).sort('system:time_start', true);

// Animation starts here

// Animation Library taken from Gennadii's packages and modified
var pad = function pad(n, width, z) {
  z = z || '0';
  n = n + '';
  return n.length >= width ? n : new Array(width - n.length + 1).join(z) + n;
};

var timeout = null;
var play = false;

function addAnimationControls(layers, position, timeStep, width, compact) {
  var currentIndex = 0;

  layers.map(function(l) { 
    l.setOpacity(0);
  });

  var showLayer = function (index) {
    layers[currentIndex].setOpacity(0);
    var l = layers[index];
    l.setOpacity(1);
    currentIndex = index;

    // update visibility if needed
    var shown = l.getShown();
    if(!shown) {
      l.setShown(true);
    }
    label.setValue(layers[index].getName());
  };

  var label = ui.Label('');

  function nextFrame() {
    var index = currentIndex + 1;
    if(index >= layers.length) {
      index = 0;
    }

    slider.setValue(index);
    
    if(play) {
      ui.util.setTimeout(nextFrame, timeStep);
    }
  }

  function onPlayPause() {
    if(!play && !timeout) {
      timeout = ui.util.setTimeout(nextFrame, timeStep);
      play = true;
      buttonPlayPause.setLabel(textPause);
    } else {
      ui.util.clearTimeout(timeout);
      timeout = null;
      play = false;
      buttonPlayPause.setLabel(textPlay);
    }
  }
  
  var textPlay = '▶';
  var textPause = '⏸';
  
  var buttonPlayPause = ui.Button(textPlay, onPlayPause);

  var slider = ui.Slider({
    min: 0,
    max: layers.length - 1,
    step: 1,
    style: {stretch: 'horizontal'}
  });

  slider.onSlide(showLayer);

  var widgets = [ui.Label('Amazon Fire 2019'), buttonPlayPause, slider, label];

  // Create a panel that contains both the slider and the label.
  var panel = ui.Panel({
    widgets: widgets,
    layout: ui.Panel.Layout.flow('horizontal'),
    style: {
      position: position,
      padding: '7px',
      width: width
    }
  });
  
  Map.add(panel);

  layers[0].setOpacity(1);
  
  // loop
  function delay(millis, callback) {
    var before = Date.now();
    
    function loop() {
      ee.Number(Date.now()).evaluate(function(now) { 
        if(now < before + millis) {
          loop();
        } else {
          callback();
        }
      });
    }
    loop();
  }
  
  function setTimeout(interval, action) {
    delay(interval, function() {
      action();
      setTimeout(interval, action);
    });
  }
  return panel;
}

/***
 * Animates a maxImageCount images from a given image collection, adds them as layers so that GMap caching can be used
 */
function animate(images, options) {
  var maxFrames = (options && options.maxFrames) || 30;
  var width = (options && options.width) || '600px';
  var vis = (options && options.vis) || {};
  var position = (options && options.position) || 'top-center';
  var timeStep = (options && options.timeStep) || 100;

  var preload = true;
  
  if(options && options.preload != 'undefined') {
    preload = options.preload;
  }
  
  images = ee.ImageCollection(images).toList(maxFrames, 0);

  maxFrames = images.size().min(maxFrames);
  
  // add loading panel
  var label = ui.Label('Loading images, please wait ....');
  var panel = ui.Panel({
    widgets: [label],
    layout: ui.Panel.Layout.flow('horizontal'),
    style: {
      position: position,
      padding: '7px',
      width: width
    }
  });
  Map.widgets().add(panel);

  // chaining
  var s = {};
  s.panel = panel;

  var lodingPanel = panel;
  ee.List.sequence(1, maxFrames).evaluate(function(indices) {
    var layers = [];

    indices.map(function(i) {
      var image = ee.Image(images.get(i-1));
      //var name = prefix + ' ' + pad(i, 2);

      var date = ee.Date(image.get('system:time_start'));
      //var name = date.get('year').getInfo() + '-' + pad(date.get('month').getInfo(), 2) + '-' + pad(date.get('day').getInfo(), 2);
      var name = date.get('year').getInfo() + '-' + date.get('month').getInfo() + '-' + date.get('day').getInfo();

      if(options && options.clipArea) {
        image = image.clip(options.clipArea);
      }

      var visible = preload;

      if(options && options.preloadCount && i > options.preloadCount) {
        visible = false;
      }
      var layer = ui.Map.Layer(image, vis, name, visible);
      Map.layers().add(layer);
      layers.push(layer);
    });
    // remove loading panel
    Map.widgets().remove(lodingPanel);

    var panel = addAnimationControls(layers, position, timeStep, width);
    // replace panel
    s.panel = panel;
  });

  return s;
}
// Animation ends here

animate(firms, {maxFrames: 100, timeStep: 600});