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Lat­est ver­sion: V2.2 (released March 2, 2018)

Mul­ti-Source Weight­ed-Ensem­ble Pre­cip­i­ta­tion (MSWEP) is a new ful­ly glob­al his­toric pre­cip­i­ta­tion dataset (1979–2017) with a 3-hourly tem­po­ral and 0.1° spa­tial res­o­lu­tion.

Why use MSWEP?

  1. MSWEP takes advan­tage of the com­ple­men­tary strengths of gauge-, satel­lite-, and reanaly­sis-based data to pro­vide reli­able pre­cip­i­ta­tion esti­mates over the entire globe.
  2. In two com­pre­hen­sive large-scale eval­u­a­tions, MSWEP per­formed best over­all (Beck et al., 2017; Beck et al., 2018).
  3. Tru­ly glob­al cov­er­age (includ­ing ocean areas) at 3-hourly 0.1° res­o­lu­tion (oth­er satel­lite-based datasets, such as TMPA 3B42, are lim­it­ed to lat­i­tudes <50/60°).
  4. Con­sis­tent pre­cip­i­ta­tion record from 1979 until the near present, enabling trend and drought assess­ments.
  5. Dai­ly (rather than month­ly) gauge cor­rec­tions using obser­va­tions from ~77,000 sta­tions across the globe.
  6. When apply­ing the dai­ly gauge cor­rec­tions, MSWEP accounts for dif­fer­ences in gauge report­ing times.
  7. Cor­rec­tion of sys­tem­at­ic ter­res­tri­al pre­cip­i­ta­tion bias­es using riv­er dis­charge obser­va­tions from 13,762 sta­tions across the globe.

Val­i­da­tion

MSWEP has been part of two com­pre­hen­sive eval­u­a­tion stud­ies. In the first, 22 grid­ded pre­cip­i­ta­tion datasets were val­i­dat­ed using obser­va­tions from ~70,000 gauges and hydro­log­i­cal mod­el­ing for ~9000 catch­ments glob­al­ly:

For each catch­ment, the pre­cip­i­ta­tion dataset that pro­vid­ed the best stream­flow sim­u­la­tions. Adapt­ed from Beck et al. (2017).

In the sec­ond, 26 pre­cip­i­ta­tion datasets were eval­u­at­ed using Stage-IV gauge-radar data for the CONUS:

Kling-Gup­ta Effi­cien­cy (KGE) scores for 26 pre­cip­i­ta­tion datasets using the Stage-IV gauge-radar dataset as ref­er­ence. High­er KGE val­ues cor­re­spond to bet­ter per­for­mance. Uncor­rect­ed datasets are list­ed in blue, where­as gauge-cor­rect­ed datasets are list­ed in red. Adapt­ed from Beck et al. (2018).

Method­ol­o­gy

MSWEP opti­mal­ly merges a wide range of gauge, satel­lite, and reanaly­sis data to pro­vide reli­able pre­cip­i­ta­tion esti­mates over the entire globe. See the fol­low­ing paper for a detailed descrip­tion of the MSWEP V2 method­ol­o­gy:

The fol­low­ing paper describes the MSWEP V1 method­ol­o­gy:

The most impor­tant changes in V2 com­pared to V1 include: (i) the intro­duc­tion of cumu­la­tive dis­tri­b­u­tion func­tion and pre­cip­i­ta­tion fre­quen­cy cor­rec­tions, to account for spu­ri­ous driz­zle and atten­u­at­ed peaks evi­dent in V1; (ii) increas­ing spa­tial res­o­lu­tion from 0.25° to 0.1° to increase the local rel­e­vance of the pre­cip­i­ta­tion esti­mates (espe­cial­ly impor­tant for high water-yield moun­tain­ous regions); (iii) the inclu­sion of ocean areas to enable ocean­ic stud­ies and ter­res­tri­al hydrol­o­gy stud­ies for coastal areas and small islands; (iv) the addi­tion of pre­cip­i­ta­tion esti­mates derived from Grid­ded Satel­lite (Grid­Sat) ther­mal infrared imagery for the pre-TRMM era to sup­ple­ment the reanaly­sis and gauge data; (v) the use of a dai­ly (rather than month­ly) gauge cor­rec­tion scheme that accounts for region­al dif­fer­ences in report­ing times, to min­i­mize tim­ing mis­match­es when apply­ing the dai­ly gauge cor­rec­tions; (vi) the use of a large data­base of dai­ly gauge obser­va­tions com­piled from sev­er­al sources to replace the 0.5° CPC Uni­fied dataset; and (vii) exten­sion of the data record to 2017 (MSWEP V1 fin­ished in 2016).

See the tech­ni­cal doc­u­men­ta­tion for the com­plete ver­sion his­to­ry.

Data access

Access to the MSWEP dataset is facil­i­tat­ed by Prince­ton Cli­mate Ana­lyt­ics, Inc. For sci­en­tif­ic col­lab­o­ra­tions or ques­tions, please send Hylke Beck a mes­sage.

Acknowl­edge­ments

MSWEP is devel­oped by Hylke Beck (Prince­ton Uni­ver­si­ty, Prince­ton, NJ, USA). The pre­cip­i­ta­tion dataset devel­op­ers are grate­ful­ly acknowl­edged for pro­duc­ing and mak­ing avail­able their datasets. The work was sup­port­ed through IPA sup­port from the U.S. Army Corps of Engi­neers’ Inter­na­tion­al Cen­ter for Inte­grat­ed Water Resources Man­age­ment (ICI­WaRM), under the aus­pices of UNESCO. By using MSWEP in any pub­li­ca­tion you agree to cite Beck et al. (2019).