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Description

M2TUNXFLX (or tavgU_2d_flx_Nx) is a time-averaged 2-dimensional monthly diurnal means data collection in Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2). This collection consists of assimilated surface flux diagnostics, such as total precipitation, bias corrected total precipitation, surface air temperature, surface specific humidity, surface wind speed, and evaporation from turbulence. The “surface” in this data collection is the model surface layer. The heights of the model surface layer (HLML) vary with time and location, with the value of ~60 meter above ground. This data collection is the monthly mean of data fields for each hour and time-stamped with the central time of an hour starting from 00:30 UTC, e.g.: 00:30, 01:30, … , 23:30 UTC.

MERRA-2 is the latest version of global atmospheric reanalysis for the satellite era produced by NASA Global Modeling and Assimilation Office (GMAO) using the Goddard Earth Observing System Model (GEOS) version 5.12.4. The dataset covers the period of 1980-present with the latency of ~3 weeks after the end of a month.

Data Reprocessing: Please check “Records of MERRA-2 Data Reprocessing and Service Changes” linked from the “Documentation” tab on this page. Note that a reprocessed data filename is different from the original file.

MERRA-2 Mailing List: Sign up to receive information on reprocessing of data, changing of tools and services, as well as data announcements from GMAO. Contact the GES DISC Help Desk (gsfc-dl-help-disc@mail.nasa.gov) to be added to the list.

Questions: If you have a question, please read "MERRA-2 File Specification Document", “MERRA-2 Data Access – Quick Start Guide”, and FAQs linked from the ”Documentation” tab on this page. If that does not answer your question, you may post your question to the NASA Earthdata Forum (forum.earthdata.nasa.gov) or email the GES DISC Help Desk (gsfc-dl-help-disc@mail.nasa.gov).

Version Description

The GEOS-5 model version used for processing MERRA-2

Product Summary

Platforms
MERRA-2
Instruments
NOT APPLICABLE
Spatial Extent

N: 90 S: -90 E: 180 W: -180

Spatial Resolution
0.625 Decimal Degrees x 0.5 Decimal Degrees
Location
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
1980-01-01 to Present
Data Partner
Goddard Earth Sciences Data and Information Services Center (formerly Goddard DAAC), Terrestrial Information Systems Laboratory, Earth Sciences Division, Science and Exploration Directorate, Goddard Space Flight Center, NASA (NASA/GSFC/SED/ESD/TISL/GESDI
Concept ID
C1276812872-GES_DISC
Data State
ACTIVE
Number of Files/Granules
555
Processing Level
4
Published
Updated
Science Keywords
Heat Flux ,
Air Temperature ,
Skin Temperature ,
Specific Humidity ,
Water Vapor ,
Precipitation Rate ,
Snow/Ice ,
Evaporation ,
Latent Heat Flux ,
Latent Heat Flux ,
Sensible Heat Flux ,
Diffusion ,
Surface Winds ,
Wind Speed ,
U/V Wind Components ,
Wind Stress ,
Wind Stress ,
Surface Roughness ,
Planetary Boundary Layer Height ,
Ice Fraction

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

Global Modeling And Assimilation Office, & Pawson, S. (2015). MERRA-2 tavgU_2d_flx_Nx: 2d,Diurnal,Time-Averaged,Single-Level,Assimilation,Surface Flux Diagnostics V5.12.4 [Data set]. NASA Goddard Earth Sciences Data and Information Services Center. https://doi.org/10.5067/LUHPNWAKYIO3 Date Accessed: 2026-05-01

Documents

Publications Citing This Dataset

Filters
Title Year Author Topic
Quantitative assessment of vegetation-driven removal of key air Liu, Tong, Yao, Jiaqi, Cao, Yongqiang, Lu, Lijun, Chang, Huanyu, Ren, He, Mo, Fan, Wang, Xuan, Xu, Nan Heat Flux, Air Temperature, Skin Temperature, Specific Humidity, Water Vapor, Precipitation Rate, Snow/Ice, Evaporation, Latent Heat Flux, Latent Heat Flux, Sensible Heat Flux, Diffusion, Surface Winds, Wind Speed, U/V Wind Components, Wind Stress, Wind Stress, Surface Roughness, Planetary Boundary Layer Height, Ice Fraction, Leaf Area Index (LAI), Fraction Of Absorbed Photosynthetically Active Radiation (fapar), Land Use/Land Cover Classification
Hue Angle-Based Remote Sensing of Secchi Disk Depth Using Sentinel-3 Huo, Yongwei, Zhao, Sufang, Yuan, Zhongjie, Wang, Xiang, Wang, Lin Heat Flux, Air Temperature, Skin Temperature, Specific Humidity, Water Vapor, Precipitation Rate, Snow/Ice, Evaporation, Latent Heat Flux, Latent Heat Flux, Sensible Heat Flux, Diffusion, Surface Winds, Wind Speed, U/V Wind Components, Wind Stress, Wind Stress, Surface Roughness, Planetary Boundary Layer Height, Ice Fraction
the SESaME Human-Earth atlas Faisal, Abdullah Al, Kaye, Maxwell, Ahmed, Maimoonah, Galbraith, Eric D. Heat Flux, Air Temperature, Skin Temperature, Specific Humidity, Water Vapor, Precipitation Rate, Snow/Ice, Evaporation, Latent Heat Flux, Latent Heat Flux, Sensible Heat Flux, Diffusion, Surface Winds, Wind Speed, U/V Wind Components, Wind Stress, Wind Stress, Surface Roughness, Planetary Boundary Layer Height, Ice Fraction, AEROSOL ABSORPTION, UV Aerosol Index, Land Use/Land Cover Classification, Photosynthesis, Primary Production, VEGETATION PRODUCTIVITY, Biomass, Forests, Grasslands, Alpine/Tundra
Study of Changes in the Concentration of Greenhouse Gases in the Atmosphere in the Ural Region Based on Reanalysis and Satellite Measurements: Part 1 ... Dzholumbetov, S. K., Markelov, Y. I. Surface Pressure, Heat Flux, Longwave Radiation, Shortwave Radiation, Surface Temperature, Humidity, Evapotranspiration, Surface Winds, Rain, Precipitation Rate, Snow, Soil Moisture/Water Content, Soil Temperature, Land Surface Temperature, Snow Water Equivalent, Runoff, Air Temperature, Skin Temperature, Specific Humidity, Water Vapor, Snow/Ice, Evaporation, Latent Heat Flux, Latent Heat Flux, Sensible Heat Flux, Diffusion, Surface Winds, Wind Speed, U/V Wind Components, Wind Stress, Wind Stress, Surface Roughness, Planetary Boundary Layer Height, Ice Fraction, Vegetation Index, Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI)
Intensification mechanisms and moisture dynamics of super cyclonic storm 'Amphan'over the Bay of Bengal: Implications for aerosol re-distribution Singh, Vivek, Srivastava, Atul Kumar, Gupta, Anu, Konduru, Rakesh Teja, Singh, Amarendra, Singh, Sumit, Kumar, Arun, Bisht, Deewan Singh, Singh, Abhay Kumar Geopotential Height, Altitude, Surface Temperature, Skin Temperature, Upper Air Temperature, Dew Point Temperature, Air Temperature, Cloud Top Temperature, Atmospheric Winds, Surface Winds, U/V Wind Components, Upper Level Winds, U/V Wind Components, Vertical Wind Velocity/Speed, Atmospheric Pressure, Sea Level Pressure, Cloud Top Pressure, Sea Level Pressure, Surface Pressure, Specific Humidity, Total Precipitable Water, Cloud Liquid Water/Ice, Atmospheric Water Vapor, Atmospheric Ozone, Oxygen Compounds, Boundary Layer Winds, Total Ozone, Albedo, Cloud Properties, Cloud Fraction, Particle Size Distribution, Cloud Optical Depth/Thickness, Aerosols, Aerosol Extinction, Aerosol Optical Depth/Thickness, Angstrom Exponent, Aerosol Particle Properties, Carbonaceous Aerosols, Dust/Ash/Smoke, Organic Particles, Sulfate Particles, Sulfur Oxides, Sulfur Compounds, Sulfate, Sulfur Dioxide, Sulfur Oxides, Particulate Matter, Dimethyl Sulfide, Black Carbon, Sea Salt, PARTICULATE MATTER (PM 2.5), PARTICULATE MATTER (PM 1.0), PARTICULATE MATTER (PM 10), Heat Flux, Water Vapor, Precipitation Rate, Snow/Ice, Evaporation, Latent Heat Flux, Latent Heat Flux, Sensible Heat Flux, Diffusion, Surface Winds, Wind Speed, Wind Stress, Wind Stress, Surface Roughness, Planetary Boundary Layer Height, Ice Fraction
Rising Planetary Boundary Layer Height over the Sahara Desert and Arabian Peninsula in a Warming Climate Zhou, Liming, Tian, Yuhong, Wei, Nan, Ho, Shu-peng, Li, Jing Geopotential Height, Atmospheric Ozone, Sea Level Pressure, Surface Pressure, Upper Air Temperature, Vertical Profiles, Air Temperature, Specific Humidity, U/V Wind Components, U/V Wind Components, Ozone Profiles, Heat Flux, Skin Temperature, Water Vapor, Precipitation Rate, Snow/Ice, Evaporation, Latent Heat Flux, Latent Heat Flux, Sensible Heat Flux, Diffusion, Surface Winds, Wind Speed, Wind Stress, Wind Stress, Surface Roughness, Planetary Boundary Layer Height, Ice Fraction, Altitude, Surface Temperature, Dew Point Temperature, Cloud Top Temperature, Atmospheric Winds, Surface Winds, Upper Level Winds, Vertical Wind Velocity/Speed, Atmospheric Pressure, Cloud Top Pressure, Sea Level Pressure, Total Precipitable Water, Cloud Liquid Water/Ice, Atmospheric Water Vapor, Oxygen Compounds, Boundary Layer Winds
The Role of Open Access Data in Geospatial Electrification Planning and Korkovelos, Alexandros, Khavari, Babak, Sahlberg, Andreas, Howells, Mark, Arderne, Christopher Heat Flux, Air Temperature, Skin Temperature, Specific Humidity, Water Vapor, Precipitation Rate, Snow/Ice, Evaporation, Latent Heat Flux, Latent Heat Flux, Sensible Heat Flux, Diffusion, Surface Winds, Wind Speed, U/V Wind Components, Wind Stress, Wind Stress, Surface Roughness, Planetary Boundary Layer Height, Ice Fraction, Infrastructure, Food Security, Conservation, Environmental Health Factors, Urbanization/Urban Sprawl
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Variables

The table below lists the variables contained within a single granule for this dataset. Variables often contain observed or derived geophysical measurements collected from a variety of sources, including remote sensing instruments on satellite and airborne platforms, field campaigns, in situ measurements, and model outputs. The terms variable, parameter, scientific data set, layer, and band have been used across NASA’s Earth science disciplines; however, variable is the designated nomenclature in NASA’s Common Metadata Repository (CMR). Variable metadata attributes such as Name, Description, Units, Data Type, Fill Value, Valid Range, and Scale Factor allow users to efficiently process and analyze the data. The full range of attributes may not be applicable to all variables. Additional information on variable attributes is typically available in the data, user guide, and/or other product documentation.

For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor Offset
BSTAR BSTAR m s-2 float32 999999986991104 N/A N/A N/A
CDH CDH kg m-2 s-1 float32 999999986991104 N/A N/A N/A
CDM CDM kg m-2 s-1 float32 999999986991104 N/A N/A N/A
CDQ CDQ kg m-2 s-1 float32 999999986991104 N/A N/A N/A
CN CN 1 float32 999999986991104 N/A N/A N/A
DISPH DISPH m float32 999999986991104 N/A N/A N/A
EFLUX EFLUX W m-2 float32 999999986991104 N/A N/A N/A
EVAP EVAP kg m-2 s-1 float32 999999986991104 N/A N/A N/A
FRCAN FRCAN 1 float32 999999986991104 N/A N/A N/A
FRCCN FRCCN 1 float32 999999986991104 N/A N/A N/A
FRCLS FRCLS 1 float32 999999986991104 N/A N/A N/A
FRSEAICE FRSEAICE 1 float32 999999986991104 N/A N/A N/A
GHTSKIN GHTSKIN W m-2 float32 999999986991104 N/A N/A N/A
HFLUX HFLUX W m-2 float32 999999986991104 N/A N/A N/A
HLML HLML m float32 999999986991104 N/A N/A N/A
lat lat degrees_north float64 N/A N/A N/A N/A
lon lon degrees_east float64 N/A N/A N/A N/A
NIRDF NIRDF W m-2 float32 999999986991104 N/A N/A N/A
NIRDR NIRDR W m-2 float32 999999986991104 N/A N/A N/A
PBLH PBLH m float32 999999986991104 N/A N/A N/A
PGENTOT PGENTOT kg m-2 s-1 float32 999999986991104 N/A N/A N/A
PRECANV PRECANV kg m-2 s-1 float32 999999986991104 N/A N/A N/A
PRECCON PRECCON kg m-2 s-1 float32 999999986991104 N/A N/A N/A
PRECLSC PRECLSC kg m-2 s-1 float32 999999986991104 N/A N/A N/A
PRECSNO PRECSNO kg m-2 s-1 float32 999999986991104 N/A N/A N/A
PRECTOT PRECTOT kg m-2 s-1 float32 999999986991104 N/A N/A N/A
PRECTOTCORR PRECTOTCORR kg m-2 s-1 float32 999999986991104 N/A N/A N/A
PREVTOT PREVTOT kg m-2 s-1 float32 999999986991104 N/A N/A N/A
QLML QLML 1 float32 999999986991104 N/A N/A N/A
QSH QSH kg kg-1 float32 999999986991104 N/A N/A N/A
QSTAR QSTAR kg kg-1 float32 999999986991104 N/A N/A N/A
RHOA RHOA kg m-3 float32 999999986991104 N/A N/A N/A
RISFC RISFC 1 float32 999999986991104 N/A N/A N/A
SPEED SPEED m s-1 float32 999999986991104 N/A N/A N/A
SPEEDMAX SPEEDMAX m s-1 float32 999999986991104 N/A N/A N/A
TAUGWX TAUGWX N m-2 float32 999999986991104 N/A N/A N/A
TAUGWY TAUGWY N m-2 float32 999999986991104 N/A N/A N/A
TAUX TAUX N m-2 float32 999999986991104 N/A N/A N/A
TAUY TAUY N m-2 float32 999999986991104 N/A N/A N/A
TCZPBL TCZPBL m float32 999999986991104 N/A N/A N/A
time time minutes since 2024-12-01 00:30:00 int32 N/A N/A N/A N/A
TLML TLML K float32 999999986991104 N/A N/A N/A
TSH TSH K float32 999999986991104 N/A N/A N/A
TSTAR TSTAR K float32 999999986991104 N/A N/A N/A
ULML ULML m s-1 float32 999999986991104 N/A N/A N/A
USTAR USTAR m s-1 float32 999999986991104 N/A N/A N/A
VLML VLML m s-1 float32 999999986991104 N/A N/A N/A
Z0H Z0H m float32 999999986991104 N/A N/A N/A
Z0M Z0M m float32 999999986991104 N/A N/A N/A
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