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 dai­ly gauge report­ing times, to min­i­mize tim­ing mis­match­es when apply­ing the dai­ly gauge cor­rec­tions; and (vii) exten­sion of the data record to 2016.

Data access

Please fill in the web form to obtain access to MSWEP. We will get back to you in about one or two days with details on how to access the data. For ques­tions, please con­tact Hylke Beck. 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).