PML_V2.2a: Coupled Evapotranspiration and Gross Primary Product (MODIS Edition)

projects/pml_evapotranspiration/PML/OUTPUT/PML_V22a
info

This dataset is part of a Publisher Catalog, and not managed by Google Earth Engine. Contact Large Scale Hydrology Lab for bugs or view more datasets from the Large Scale Hydrology Lab Catalog. Learn more about Publisher datasets.

Catalog Owner
Large Scale Hydrology Lab
Dataset Availability
2000-03-05T00:00:00Z–2024-12-26T00:00:00Z
Dataset Producer
Earth Engine Snippet
ee.ImageCollection("projects/pml_evapotranspiration/PML/OUTPUT/PML_V22a")
Cadence
8 Days
Tags
evapotranspiration gpp plant-productivity publisher-dataset water-vapor
pml-evapotranspiration

Description

The dataset is produced by the Large Scale Hydrology Lab, which specializes in advancing global and regional water cycle research by synthesizing multi-source Earth observations with process-based modeling.

The PML-V2.2a (MODIS Edition) product provides global terrestrial evapotranspiration (ET) and gross primary production (GPP) at a 500-m, 8-day resolution from 2000 to 2024. Forced by MSWEP and MSWX data, this version features an expanded bottom-up calibration using 208 flux sites and refined parameterizations that explicitly distinguish irrigated from rainfed croplands.

Validation confirms high accuracy across plant functional types (NSE > 0.60, absolute bias < 5%) and reliable basin-scale water-balance performance (NSE: 0.89–0.91). Optimized for high-resolution eco-hydrological monitoring, this MODIS-based record provides a robust historical baseline. Due to satellite orbital drift, this asset will no longer be updated post-2024. For near-present monitoring and data extending to 2025, please refer to the companion VIIRS Edition asset, which ensures seamless data continuity.

This dataset is part of the broader PML-V2.2 suite, where the description preprint is available at Earth System Science Data. For the long-term and consolidated record (1982-near present, PML-V2.2a/b/c at 0.1° resolution with different remote sensing forcings), please visit the TPDC data repository.

Bands

Bands

Pixel size: 500 meters (all bands)

Name Units Min Max Scale Pixel Size Description
GPP gC m-2 d-1 0* 3901* 0.01 500 meters

Gross primary production

ET mm/d 0* 2011* 0.01 500 meters

Evapotranspiration

Ec mm/d 0* 1533* 0.01 500 meters

Transpiration

Es mm/d 0* 820* 0.01 500 meters

Soil evaporation

Ei mm/d 0* 1256* 0.01 500 meters

Interception evaporation

PET mm/d 0* 2011* 0.01 500 meters

Potential evapotranspiration (PET) estimated using the Shuttleworth-simplified Penman equation.

Ew mm/d 0* 2011* 0.01 500 meters

Evaporation from water bodies, snow, and ice, estimated using the Penman equation with unlimited water supply.

* estimated min or max value

Terms of Use

Terms of Use

Acknowledgements Whenever PML datasets are used in a scientific publication, the given references should be cited.

License The dataset is licensed under the CC-BY 4.0 license.

Citations

Citations:
  • Zhang, Y., Kong, D., Gan, R., Chiew, F.H.S., McVicar, T.R., Zhang, Q., and Yang, Y., 2019. Coupled estimation of 500m and 8-day resolution global evapotranspiration and gross primary production in 2002-2017. Remote Sens. Environ. 222, 165-182, doi:10.1016/j.rse.2018.12.031

  • Gan, R., Zhang, Y.Q., Shi, H., Yang, Y.T., Eamus, D., Cheng, L., Chiew, F.H.S., Yu, Q., 2018. Use of satellite leaf area index estimating evapotranspiration and gross assimilation for Australian ecosystems. Ecohydrology, doi:10.1002/eco.1974

  • Zhang, Y., Peña-Arancibia, J.L., McVicar, T.R., Chiew, F.H.S., Vaze, J., Liu, C., Lu, X., Zheng, H., Wang, Y., Liu, Y.Y., Miralles, D.G., Pan, M., 2016. Multi-decadal trends in global terrestrial evapotranspiration and its components. Sci. Rep. 6, 19124. doi:10.1038/srep19124

DOIs

Explore with Earth Engine

Code Editor (JavaScript)

var dataset = ee.ImageCollection('projects/pml_evapotranspiration/PML/OUTPUT/PML_V22a');

// Convert 8-day averages to annual estimate with 0.01 scale factor
var annualImage = dataset.filterDate('2024-01-01', '2024-12-31')
    .select('ET')
    .mean()
    .multiply(365)
    .multiply(0.01);
    
// Final unit: mm yr-1
var visualization = {
  bands: ['ET'],
  min: 0.0,
  max: 1600, 
  palette: [
    "#A02323", "#C80000", "#FF0000", "#FF6E00", "#FFAA00", "#FFE132", 
    "#FFFFC8", "#D2F5FF", "#A0D2FF", "#00BFFF", "#1E90FF", "#4169E1", 
    "#0000CD", "#000096"
  ]
};

Map.setCenter(0.0, 15.0, 2);

Map.addLayer(
    annualImage, visualization, 'PML_V2.2a Evapotranspiration (ET)');
Open in Code Editor