MERRA-2 FAQ: How do I obtain a time series for MERRA-2 data?

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GES DISC - jimacker
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MERRA-2 FAQ: How do I obtain a time series for MERRA-2 data?

by GES DISC - jimacker » Thu Feb 13, 2025 12:33 am America/New_York

There are a number of ways to obtain a time series of MERRA-2 data. We have written some data How-tos that provide step-by-step instructions.
  • Obtain a time series at a ___location in CSV format
How to Obtain a Time Series at a Single Point using TDS
  • Obtain a time series at a ___location in CSV format
Data Rods

Note: The Data Rods service was developed primarily to support the hydrology user community, which includes selected MERRA-2 hourly near-surface data, including air temperature, humidity, wind, and radiation. It may be used by anyone who is interested in downloading long time-series data available on this service.
  • Obtain a time series over a region in netCDF format:
How to Obtain a Spatially Subsetted Time Series using TDS



Additional information about extracting time series at a specific ___location:

The MERRA-2 dataset contains reanalysis data, which are not observations. The data may have bias or uncertainties. For example, the shortwave radiation is affected by modeled clouds which may have some significant uncertainties. Please read the MERRA-2 File Specification and related MERRA-2 documentation carefully before using the data. The model data may also have bias or uncertainties when sparse data measurements are assimilated. Please refer to the MERRA-2 documentation to determine the availablity of observations in your region of interest.

The output data in the above methods are extracted from the nearest model grid point to the given longitude and latitude. No interpolation is performed.

If your parameter of interest is sensitive to the land surface type, please consider double-checking the surface type fraction (e.g. land and water fractions) in the model grid cell where your parameter is located. For example, the shortwave radiation may be quite different over a grid cell that contains more water or land. The surface types are available in the following constants collections.

M2C0NXASM (const_2d_asm_Nx): Constant Model Parameters

M2C0NXCTM (const_2d_ctm_Nx): Constant Model Parameters for Usage by CTM

M2C0NXLND (const_2d_lnd_Nx): Constant Land‐Surface Diagnostics Parameter

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