01 CMIP6 Interpolation

var geometry =ee.FeatureCollection("projects/heatwave0214/assets/basicpolygon/Chinaregion_NOTW").geometry();

var i;
for (i = 2044; i < 2101; i++) {
    
  var stryear  = i.toString();
  var startDate = stryear.concat('-05-01');
  var startDate = ee.Date(startDate); 
  var endDate   = startDate.advance(5,'month');
    
  var dateList = ee.List.sequence(0, endDate.difference(startDate, 'day').subtract(1)).map(function(day){
    return startDate.advance(day, 'day').format('YYYY-MM-dd'); 
  });
  
  function dailyDownscaleProcess(date) {
  
      var diff_5 = ee.Image("projects/heatwave0214/assets/History_HW/diff_05");
      var diff_6 = ee.Image("projects/heatwave0214/assets/History_HW/diff_06");
      var diff_7 = ee.Image("projects/heatwave0214/assets/History_HW/diff_07");
      var diff_8 = ee.Image("projects/heatwave0214/assets/History_HW/diff_08");
      var diff_9 = ee.Image("projects/heatwave0214/assets/History_HW/diff_09");
      
      var cmip6 = ee.ImageCollection("NASA/GDDP-CMIP6");
      var filtered = cmip6.filter(ee.Filter.eq('scenario', 'ssp245')).select('tas');
      
      var dateRange = ee.DateRange(date, ee.Date(date).advance(1, 'day'));
      var selectedImages = filtered.filterDate(dateRange);
      var dailyAverage = selectedImages.mean().subtract(273.15);

      function reSampleFun(image, scale) {
        var reSampleImg = image.resample('bilinear').reproject({
                                  crs:'EPSG:4326',
                                  scale:scale
                                });
        return reSampleImg;
      }
      
      var img_10km = reSampleFun(dailyAverage, 11132);
      var TX_10km = img_10km.rename('TM_10km');

      // Extract the month from the date
      var month = ee.Date(date).get('month');
      var correction;
      
      // Select the appropriate correction factor based on the month
      correction = ee.Algorithms.If(ee.Number(month).eq(5), diff_5,
                    ee.Algorithms.If(ee.Number(month).eq(6), diff_6,
                    ee.Algorithms.If(ee.Number(month).eq(7), diff_7,
                    ee.Algorithms.If(ee.Number(month).eq(8), diff_8,
                    ee.Algorithms.If(ee.Number(month).eq(9), diff_9, ee.Image(0))))));
      
      var TX_10km_corrected = TX_10km.add(ee.Image(correction)).rename("TM_10km_corrected");

      return ee.Image(TX_10km_corrected).set('system:time_start', date); 
  }
  
  function strcon(x) {
    return ee.String('TM_10km_').cat(ee.Date(x).format('YYYY_MM_dd'));
  }
  
  var downscaleImageCollection = ee.ImageCollection.fromImages(dateList.map(function(date){
    return dailyDownscaleProcess(date);
  }));
  
  function export_img(img, folder, task){
        Export.image.toAsset({
              image : img,
              description: task,
              assetId: folder.concat('/').concat(task),
              crs:"EPSG:4326",
              scale: 11132,
              region: geometry.bounds(),
              maxPixels: 1e13
        });
  }
    
  var img_out = downscaleImageCollection.toArray();
  var ids = ee.List(downscaleImageCollection.aggregate_array('system:time_start')).map(strcon);
  img_out = img_out.arraySlice(1, -1).arrayProject([0]).arrayFlatten([ids]); //convert into image;
  
  var outstr = 'Merged_SSP245_TM_10km_interpolation_' + i.toString();
  export_img(img_out, 'SSP245_TM_10km_China', outstr);
}