google-earth-engine – Understanding Units of ERA5 Daily Aggregates in Google Earth Engine

copernicusgoogle-earth-engineprecipitation

In Google Earth Engine, ERA5 Daily Aggregates – Latest Climate Reanalysis Produced by ECMWF / Copernicus Climate Change Service Bands show the maximum total_precipitation value of 0.02m which is 20mm. Does this mean the map does not show any data for places where it has rained more than 20mm? Does this occurs in ERA5 official onsite data as well?

Best Answer

If you observe in GEE site, these are estimated min or max value; probably based in mean values.

If you run the following script for a region as Nepal; where it rains a lot:

// Example script to load and visualize ERA5 climate reanalysis parameters in
// Google Earth Engine

// Daily total precipitation sums
var era5_tp = ee.ImageCollection('ECMWF/ERA5/DAILY')
                  .select('total_precipitation')
                  .filter(ee.Filter.date('2019-07-01', '2019-07-31'));


// Visualization palette for total precipitation
var visTp = {
  min: 0,
  max: 0.1,
  palette: ['#FFFFFF', '#00FFFF', '#0080FF', '#DA00FF', '#FFA400', '#FF0000']
};


// Add layer to map
Map.addLayer(
    era5_tp.filter(ee.Filter.date('2019-07-15')), visTp,
    'Daily total precipitation sums');

Map.setCenter(84.702, 28.083, 8);

Result is as follows:

enter image description here

where a value of 0.16158650815486908 m (161.58650815486908 mm), for selected pixel inside blue square in above picture, it is huge for total precipitation (2019-07-15 day) in that point.

Related Question