Published January 1, 2015 | Version v2.0

Dataset - reanalysis Metadata-only

The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2)

Creators: NASA Global Modeling and Assimilation Office (GMAO)¹

1. NASA Global Modeling and Assimilation Office (GMAO)

Contact person:: Petrelli, Paola¹

1. University of Tasmania

Description

The Modern Era Retrospective-Analysis for Research and Applications (MERRA) is a NASA reanalysis integrating satellite observations using a major new version of the Goddard Earth Observing System Data Assimilation System Version 5 (GEOS-5).

MERRA focuses on historical analyses of the hydrological cycle on a broad range of weather and climate time scales covering the modern satellite era from 1979 to present. The state-of-the-art GEOS-5 data assimilation system includes many modern observing systems (such as EOS) in a climate framework Specifically, the GEOS-DAS Version 5 implements Incremental Analysis Updates (IAU) to slowly adjust the model states toward the observed state.

MERRA-2 is produced with the GMAO/GEOS-5 Data Assimilation System Version 5.12.4 and its native resolution is 0.5° x 0.625° x 72 hybrid sigma/pressure levels. Hourly data intervals are used for two-dimensional products, while 3-hourly intervals are used for three-dimensional products. These may be on the model's native 72-layer vertical grid or at 42 pressure surfaces extending to 0.1 hPa. MERRA-2 spans from 1979 to present (with about 5 months lag).

The 42 pressure levels are: 1000, 975, 950, 925, 900, 875, 850, 825, 800, 775, 750, 725, 700, 650, 600, 550, 500, 450, 400, 350, 300, 250, 200, 150,100, 70, 50, 40, 30, 20,10, 7, 5, 4, 3, 2, 1,0.7, 0.5, 0.4, 0.3, 0.1 hPa The 72 native grid levels are:

Information retrieved from NCAR climate re-analysis guide and GEOS-CHEM MERRA-2 wiki. The data was downloaded from the GES DISC data store where information on all the MERRA-2 products is available.

The data is hosted at NCI in two projects: rr7 and ua8

Hosted in rr7

tavg1_2d_rad_Nx

MERRA 2D,1-hourly,time-averaged,single-level,assimilation,radiation diagnostics
rr7/MERRA2/raw/M2T1NXRAD.5.12.4/yyyy/mm/MERRA2_100.tavg1_2d_rad_Nx.yyyymmdd.nc4
resolution: lat/lon - 0.5 /0.625 degrees Timestep: 1 hourly
doi: 10.5067/Q9QMY5PBNV1T
file size: 209 Mb

tavg1_2d_flx_Nx

MERRA2 2D 1-hourly,time-averaged,single-level,assimilation,surface flux diagnostics
rr7/MERRA2/raw/M2T1NXFLX.5.12.4/yyyy/mm/MERRA2_100.tavg1_2d_flx_Nx.yyyymmdd.nc4
resolution: lat/lon - 0.5 /0.625 degrees Timestep: 1 hourly
doi: 10.5067/7MCPBJ41Y0K6
file size: 380 Mb

tavg1_2d_int_Nx

MERRA 2D ,1-hourly,time-averaged,single-level,assimilation,vertically integrated diagnostics
rr7/MERRA2/raw//M2T1NXINT.5.12.4/yyyy/mm/MERRA2_100.tavg1_2d_int_Nx.yyyymmdd.nc4
resolution: lat/lon - 0.5 /0.625 degrees Timestep: 1 hourly
doi: 10.5067/Q5GVUVUIVGO7
file size: 1.3 Gb

inst6d_3d_ana_Np

MERRA 3D,6-hourly,instantaneous,pressure-level,analysis,analyzed meteorological fields
rr7/MERRA2/raw/M2I1NPANA.5.12.4/yyyy/mm/MERRA2_100.inst6_3d_ana_Np.yyyymmdd.nc4
resolution: lat/lon - 0.5 /0.625 degrees Timestep: 6 hourly Levels: 42
doi: 10.5067/A7S6XP56VZWS
file size: 511 Mb

tavg1_2d_slv_Nx

MERRA 2D,1-hourly,Time-Averaged,Single-Level,Assimilation,Single-Level Diagnostics
rr7/MERRA2/raw//M2T1NXSLV.5.12.4/yyyy/mm/MERRA2_100.tavg1_2d_slv_Nx.yyyymmdd.nc4
resolution: lat/lon - 0.5 /0.625 degrees Timestep: 1 hourly
doi: 10.5067/VJAFPLI1CSIV
file size: 400 Mb

inst3d_3d_asm_Np

MERRA 3D,3-hourly,Instantaneous,Pressure-Level,Assimilation,Assimilated Meteorological Fields
/rr7/raw/MERRA2/M2I3NPASM.5.12.4/yyyy/mm/MERRA2_100.inst3_3d_asm_Np.yyyymmdd.nc4
resolution: lat/lon - 0.5 /0.625 degrees Timestep: 3 hourly Levels: 42
doi: 10.5067/QBZ6MG944HW0
file size: 1.2 Gb

Hosted in ua8

inst1_2d_asm_Nx

MERRA-2 inst1_2d_asm_Nx: 2d,1-Hourly,Instantaneous,Single-Level,Assimilation,Single-Level Diagnostics V5.12.4
ua8/MERRA2/1hr/M2I1NXASM.5.12.4/<yyyy>/<mm>/MERRA2_100.inst1_2d_asm_Nx.<yyyymmdd>.nc4
resolution: lat/lon - 0.5 /0.625 degrees Timestep: 1 hourly
doi: 10.5067/3Z173KIE2TPD
file size: 198 MB

inst3_2d_gas_Nx

MERRA-2 inst3_2d_gas_Nx: 2d,3-Hourly,Instantaneous,Single-Level,Assimilation,Aerosol Optical Depth Analysis V5.12.4
ua8/MERRA2/3hr/M2I3NXGAS.5.12.4/<yyyy>/<mm>/MERRA2_100.inst3_2d_gas_Nx.<yyyymmdd>.nc4
doi: 10.5067/HNGA0EWW0R09
resolution: lat/lon - 0.5 /0.625 degrees Timestep: 3 hourly
file size: 9.2 MB

instM_2d_gas_Nx

MERRA-2 instM_2d_gas_Nx: 2d,Monthly mean,Instantaneous,Single-Level,Assimilation,Aerosol Optical Depth Analysis V5.12.4
ua8/MERRA2/monthly/M2IMNXGAS.5.12.4/<yyyy>/MERRA2_100.instM_2d_gas_Nx.<yyyymm>.nc4
doi: 10.5067/XOGNBQEPLUC5
resolution: lat/lon - 0.5 /0.625 degrees Timestep: monthly
file size: 9.2 MB

tavgM_2d_aer_Nx

MERRA-2 tavgM_2d_aer_Nx: 2d,Monthly mean,Time-averaged,Single-Level,Assimilation,Aerosol Diagnostics V5.12.4
ua8/MERRA2/monthly/M2TMNXAER.5.12.4/<yyyy>/MERRA2_100.tavgM_2d_aer_Nx.<yyyymm>.nc4
doi: 10.5067/FH9A0MLJPC7N
resolution: lat/lon - 0.5 /0.625 degrees Timestep: monthly
file size: 481 MB

See the official documentation for access Variables tables for each product.

Local host (English)

Direct access to the data is available on the NCI servers:

project:

path:

/g/data/ua8/MERRA2
/g/data/rr7/MERRA2

Access information (English)

To cite the available products:

Global Modeling and Assimilation Office (GMAO) (2015), MERRA-2 inst3_3d_asm_Np: 3d,3-Hourly,Instantaneous,Pressure-Level,Assimilation,Assimilated Meteorological Fields V5.12.4, Greenbelt, MD, USA, Goddard Earth Sciences Data and Information Services Center (GES DISC), Accessed: [Data Access Date], 10.5067/QBZ6MG944HW0
Global Modeling and Assimilation Office (GMAO) (2015), MERRA-2 inst6_3d_ana_Np: 3d,6-Hourly,Instantaneous,Pressure-Level,Analysis,Analyzed Meteorological Fields V5.12.4, Greenbelt, MD, USA, Goddard Earth Sciences Data and Information Services Center (GES DISC), Accessed: [Data Access Date], 10.5067/A7S6XP56VZWS
Global Modeling and Assimilation Office (GMAO) (2015), MERRA-2 tavg1_2d_flx_Nx: 2d,1-Hourly,Time-Averaged,Single-Level,Assimilation,Surface Flux Diagnostics V5.12.4, Greenbelt, MD, USA, Goddard Earth Sciences Data and Information Services Center (GES DISC), Accessed: [Data Access Date], 10.5067/7MCPBJ41Y0K6
Global Modeling and Assimilation Office (GMAO) (2015), MERRA-2 tavg1_2d_int_Nx: 2d,1-Hourly,Time-Averaged,Single-Level,Assimilation,Vertically Integrated Diagnostics V5.12.4, Greenbelt, MD, USA, Goddard Earth Sciences Data and Information Services Center (GES DISC), Accessed: [Data Access Date], 10.5067/Q5GVUVUIVGO7
Global Modeling and Assimilation Office (GMAO) (2015), MERRA-2 tavg1_2d_rad_Nx: 2d,1-Hourly,Time-Averaged,Single-Level,Assimilation,Radiation Diagnostics V5.12.4, Greenbelt, MD, USA, Goddard Earth Sciences Data and Information Services Center (GES DISC), Accessed: [Data Access Date], 10.5067/Q9QMY5PBNV1T
Global Modeling and Assimilation Office (GMAO) (2015), MERRA-2 tavg1_2d_slv_Nx: 2d,1-Hourly,Time-Averaged,Single-Level,Assimilation,Single-Level Diagnostics V5.12.4, Greenbelt, MD, USA, Goddard Earth Sciences Data and Information Services Center (GES DISC), Accessed: [Data Access Date], 10.5067/VJAFPLI1CSIV
Global Modeling and Assimilation Office (GMAO) (2015), MERRA-2 inst1_2d_asm_Nx: 2d,1-Hourly,Instantaneous,Single-Level,Assimilation,Single-Level Diagnostics V5.12.4, Greenbelt, MD, USA, Goddard Earth Sciences Data and Information Services Center (GES DISC), Accessed: [Data Access Date], 10.5067/3Z173KIE2TPD
Global Modeling and Assimilation Office (GMAO) (2015), MERRA-2 inst3_2d_gas_Nx: 2d,3-Hourly,Instantaneous,Single-Level,Assimilation,Aerosol Optical Depth Analysis V5.12.4, Greenbelt, MD, USA, Goddard Earth Sciences Data and Information Services Center (GES DISC), Accessed: [Data Access Date], 10.5067/HNGA0EWW0R09
Global Modeling and Assimilation Office (GMAO) (2015), MERRA-2 instM_2d_gas_Nx: 2d,Monthly mean,Instantaneous,Single-Level,Assimilation,Aerosol Optical Depth Analysis V5.12.4, Greenbelt, MD, USA, Goddard Earth Sciences Data and Information Services Center (GES DISC), Accessed: [Data Access Date], 10.5067/XOGNBQEPLUC5
Global Modeling and Assimilation Office (GMAO) (2015), MERRA-2 tavgM_2d_aer_Nx: 2d,Monthly mean,Time-averaged,Single-Level,Assimilation,Aerosol Diagnostics V5.12.4, Greenbelt, MD, USA, Goddard Earth Sciences Data and Information Services Center (GES DISC), Accessed: [Data Access Date], 10.5067/FH9A0MLJPC7N