@article{fdi:010055762,
  title = {{S}electing the optimal method to calculate daily global reference potential evaporation from {CFSR} reanalysis data for application in a hydrological model study},
  author = {{W}eiland, {F}. {C}. {S}. and {T}isseuil, {C}l{\'e}ment and {D}urr, {H}. {H}. and {V}rac, {M}. and {V}an {B}eek, {L}. {P}. {H}.},
  editor = {},
  language = {{ENG}},
  abstract = {{P}otential evaporation ({PET}) is one of the main inputs of hydrological models. {Y}et, there is limited consensus on which {PET} equation is most applicable in hydrological climate impact assessments. {I}n this study six different methods to derive global scale reference {PET} daily time series from {C}limate {F}orecast {S}ystem {R}eanalysis ({CFSR}) data are compared: {P}enman-{M}onteith, {P}riestley-{T}aylor and original and re-calibrated versions of the {H}argreaves and {B}laney-{C}riddle method. {T}he calculated {PET} time series are (1) evaluated against global monthly {P}enman-{M}onteith {PET} time series calculated from {CRU} data and (2) tested on their usability for modeling of global discharge cycles. {A} major finding is that for part of the investigated basins the selection of a {PET} method may have only a minor influence on the resulting river flow. {W}ithin the hydrological model used in this study the bias related to the {PET} method tends to decrease while going from {PET}, {AET} and runoff to discharge calculations. {H}owever, the performance of individual {PET} methods appears to be spatially variable, which stresses the necessity to select the most accurate and spatially stable {PET} method. {T}he lowest root mean squared differences and the least significant deviations (95% significance level) between monthly {CFSR} derived {PET} time series and {CRU} derived {PET} were obtained for a cell-specific re-calibrated {B}laney-{C}riddle equation. {H}owever, results show that this re-calibrated form is likely to be unstable under changing climate conditions and less reliable for the calculation of daily time series. {A}lthough often recommended, the {P}enman-{M}onteith equation applied to the {CFSR} data did not outperform the other methods in a evaluation against {PET} derived with the {P}enman-{M}onteith equation from {CRU} data. {I}n arid regions (e.g. {S}ahara, central {A}ustralia, {US} deserts), the equation resulted in relatively low {PET} values and, consequently, led to relatively high discharge values for dry basins (e.g. {O}range, {M}urray and {Z}ambezi). {F}urthermore, the {P}enman-{M}onteith equation has a high data demand and the equation is sensitive to input data inaccuracy. {T}herefore, we recommend the re-calibrated form of the {H}argreaves equation which globally gave reference {PET} values comparable to {CRU} derived values for multiple climate conditions. {T}he resulting gridded daily {PET} time series provide a new reference dataset that can be used for future hydrological impact assessments in further research, or more specifically, for the statistical downscaling of daily {PET} derived from raw {GCM} data. {T}he dataset can be downloaded from http://opendap.deltares.nl/thredds/dods{C}/opendap/deltares/{FEWS}-{IPCC}.},
  keywords = {},
  booktitle = {},
  journal = {{H}ydrology and {E}arth {S}ystem {S}ciences},
  volume = {16},
  numero = {3},
  pages = {983--1000},
  ISSN = {1027-5606},
  year = {2012},
  DOI = {10.5194/hess-16-983-2012},
  URL = {https://www.documentation.ird.fr/hor/fdi:010055762},
}