Lat­est ver­sion: V2.1 (released Novem­ber 20, 2017)

Mul­ti-Source Weight­ed-Ensem­ble Pre­cip­i­ta­tion (MSWEP) is a new ful­ly glob­al his­toric pre­cip­i­ta­tion dataset (1979–2016) 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 (Beck et al., 2017a).
2. In a com­pre­hen­sive glob­al-scale eval­u­a­tion of 22 pre­cip­i­ta­tion datasets, MSWEP per­formed best over­all (Beck et al., 2017b).
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.
6. When apply­ing the dai­ly gauge cor­rec­tions, MSWEP accounts for dif­fer­ences in gauge report­ing times.

Val­i­da­tion

MSWEP has been val­i­dat­ed at glob­al scale using obser­va­tions from ~70,000 gauges and hydro­log­i­cal mod­el­ing for ~9000 catch­ments (Beck et al., 2017b). The dataset was found to per­form bet­ter over­all in terms of tem­po­ral vari­abil­i­ty, trend, num­ber of dry days, peak mag­ni­tude, etc., com­pared to oth­er wide­ly used pre­cip­i­ta­tion datasets (e.g., CPC Uni­fied, CHIRPS, CMORPH-CRT, GPCP-1DD, GSMaP, PER­SIANN-CCS, PER­SIANN-CDR, WFDEI-CRU, and TMPA 3B42). See the fol­low­ing open-access paper for more infor­ma­tion:

• Beck, H. E., N. Ver­gopolan, M. Pan, V. Lev­iz­zani, A.I.J.M. van Dijk, G.P. Wee­don, L. Broc­ca, F. Pap­pen­berg­er, G.J. Huff­man, and E.F. Wood: Glob­al-scale eval­u­a­tion of 22 pre­cip­i­ta­tion datasets using gauge obser­va­tions and hydro­log­i­cal mod­el­ing, Hydrol­o­gy and Earth Sys­tem Sci­ences, 21(12), 6201–6217, 2017b.

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 open-access paper for a detailed descrip­tion of the MSWEP V1.1 method­ol­o­gy:

• Beck, H.E., A.I.J.M. van Dijk, V. Lev­iz­zani, J. Schellekens, D.G. Miralles, B. Martens, A. de Roo: MSWEP: 3-hourly 0.25° glob­al grid­ded pre­cip­i­ta­tion (1979–2015) by merg­ing gauge, satel­lite, and reanaly­sis data, Hydrol­o­gy and Earth Sys­tem Sci­ences, 21(1), 589–615, 2017a.

The method­ol­o­gy used to pro­duce the lat­est ver­sion (V2) is described in the most recent MSWEP tech­ni­cal doc­u­men­ta­tion. The paper about V2 is still in prepa­ra­tion. The most impor­tant changes in V2 com­pared to V1 include: (i) the use of cumu­la­tive dis­tri­b­u­tion func­tion match­ing to cor­rect the spu­ri­ous driz­zle and atten­u­at­ed peaks evi­dent in V1; (ii) increas­ing the spa­tial res­o­lu­tion from 0.25° to 0.1°; (iii) the inclu­sion of ocean areas; (iv) the addi­tion of infrared-based pre­cip­i­ta­tion esti­mates for the pre-TRMM era to sup­ple­ment the reanaly­sis and gauge data; (v) the addi­tion of 0.1° dai­ly inter­po­lat­ed gauge data to replace the coarse (0.5°) CPC Uni­fied dataset; (vi) the use of a dai­ly gauge cor­rec­tion scheme that accounts for dif­fer­ences in gauge report­ing times, to min­i­mize tim­ing mis­match­es when apply­ing the dai­ly gauge cor­rec­tions; and (vii) exten­sion of the data record to 2016.

Data access

June 26, 2018 — MSWEP is not avail­able for down­load at this moment. Data dis­tri­b­u­tion will be resumed in a few weeks time. Apolo­gies for the incon­ve­nience.

The lat­est tech­ni­cal doc­u­men­ta­tion, includ­ing the ver­sion his­to­ry and exam­ples on how to read the data with MAT­LAB and Python, is avail­able here.

Acknowl­edge­ments

MSWEP is being 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. (2017a).