MERRA-2

The Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) is a reanalysis product from NASA/GMAO. It provides data continuous in time and space for 1980-present day through the itegration of satellite based data and conventional weather observations into a modelling framework. It is produced using the GEOS-5 atmospheric data assimilation system. It replaces the original MERRA dataset using advancements made in assimilation techniques.

When compared to other long-term reanalyses, MERRA-2 has many variables and fields unique to it, for example it is the first to use space-based observations of aerosols.

Documentation

MERRA-2 Data at the IACDC

Information on what MERRA 2 Reanalysis data is ready for download at the IACDC can be found at the bottom of this page.

Should you require data not currently available, you can place a request for it at the MERRA 2 data request page. We will be happy to download it and have it stored temporarily with us.

 

Alternatively MERRA-2 data can be downloaded via http://disc.sci.gsfc.nasa.gov/daac-bin/FTPSubset.pl

MERRA-2 Filenames at the IACDC

At the IACDC, MERRA 2 filenames follow a convention similar to that set by Obs4MIPs. (https://www.earthsystemcog.org/projects/obs4mips/).

In the following format: field_time-frequency_reanalysis_MERRA2_product_yyyymmdd.nc

So for example, air temperature on pressure levels, from the MERRA 2 inst3-3d-asm-Np product with a daily temporal resolution for the 7th of July 2016 has the following filename: ta_day_reanalysis_MERRA2_inst3-3d-asm-Np_20160707.nc4

More information on field names in the Obs4MIPs format can be found at https://pcmdi.llnl.gov/mips/cmip5/docs/standard_output.pdf?id=97 which gives information on the standard output for CMIP5.

Citation

MERRA-2 data used must be properly cited in accordance with GES DISC data policy which can be found by following: http://disc.sci.gsfc.nasa.gov/additional/ges_disc_data_policy

Listing of MERRA-2 Data Available to Download at the IACDC

Product Variable Spatial resolution Spatial coverage Temporal resolution Time span
inst3_3d_asm_Np ta 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-31/07/2016
inst3_3d_asm_Np ua 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-31/07/2016
inst3_3d_asm_Np va 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-31/07/2016
inst3_3d_asm_Np wap 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-31/07/2016
inst1_2d_asm_Nx tas 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-31/01/2017
inst1_2d_asm_Nx uas 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-28/02/2017
inst1_2d_asm_Nx vas 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-28/02/2017
inst1_2d_asm_Nx ts 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-28/02/2017
inst1_2d_asm_Nx ps 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-28/02/2017
inst1_2d_asm_Nx psl 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-28/02/2017
inst1_2d_asm_Nx huss 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-28/02/2017
inst1_2d_asm_Nx rlds 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-28/02/2017
inst1_2d_asm_Nx rlus 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-28/02/2017
inst1_2d_asm_Nx rlut 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-28/02/2017
inst1_2d_asm_Nx rsdt 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-28/02/2017
inst1_2d_asm_Nx rsds 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-28/02/2017
inst1_2d_asm_Nx rldscs 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-28/02/2017
inst1_2d_asm_Nx rlutcs 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-28/02/2017
inst1_2d_asm_Nx rsdscs 0.5˚x0.625˚ [90˚S-90˚N, -180˚E-179.375˚E] day 01/01/2006-28/02/2017

References