Derived Optimal Linear Combination Evapotranspiration - DOLCE

Similarly to DOLCE V2.0, DOLCE V2.1 is a new hybrid Evapotranspiration (ET) dataset derived by merging 11 available global ET datasets. These include BACI, FLUXCOM RS, FLUXCOM MET, ERA5-land, GLEAM v3.3a, GLEAM v3.3b, PML-CSIRO, PSLH, MOD16, SEBS, and SRB-GEWEX.

The contribution of each dataset to DOLCE V2 is based on its ability to match field observations as well as its dependence to the other parent datasets. DOLCE V2 provides time-variant estimates of its uncertainty errors, which are consistent with its agreement with field observations.
The difference between DOLCE V2.1 and DOLCE V2.0 is that in the latter, ERA5-land was included in the merge during 2001 and 2018 only, while in the former, ERA5-land is included from 1981 to 2018.
DOLCE V2.# and its previous version DOLCE V1 use the same merging technique and provide monthly ET estimates and associated uncertainties over the global land. There are several improvements implemented in DOLCE V2.#, these include (DOLCE V2.# vs DOLCE V1):

Employing a wider range of parent datasets (11 parents vs 6 parent datasets)

Incorporating more field observations to constrain the merging technique (260 sites vs 160 sites)

Finer spatial resolution (0.25° vs 0.5°).

Longer temporal coverage (1980-2018 vs 2000-2009).

Datasets employed to derive DOLCE V2.1:

BACI

FLUXCOM RS

FLUXCOM MET

ERA5-land

GLEAM v3.3a

GLEAM v3.3b

PML-CSIRO

PSLH

MOD16

SEBS

SRB-GEWEX.

Field observations from flux tower networks including:

FLUXNET2015-tier1

LaThuile Free Fair Use 

CarboEurope

AmeriFlux

ARM

AsiaFlux

Oak Ridge

Ozflux

Data acquired through communication with Principal Investigators.

The final output is a monthly, 0.5-degree dataset of terrestrial Evapotranspiration and its error estimates over 1980-2018. The dataset is provided as yearly NETCDF4 files.

This dataset was produced by Dr Sanaa Hobeichi as part of her PhD thesis and of the Centre of Excellence for Climate System Science "The role of land surface forcing and feedbacks for regional climate" research program.