MERRA-2 M2T1NXFLX: Surface Flux Diagnostics V5.12.4

Page Summary

• The M2T1NXFLX dataset is an hourly time-averaged collection of surface flux diagnostics from the MERRA-2 reanalysis, including variables like precipitation, surface air temperature, and wind speed.

• This dataset covers the period from 1980 to the present with a latency of approximately three weeks.

• Provided by NASA/MERRA, the data includes detailed bands describing various atmospheric and surface parameters.

• The data is available for full and open sharing with research and application communities, private industry, academia, and the general public.

Dataset Availability

1980-01-01T00:00:00Z–2026-02-01T23:00:00Z

Dataset Producer

NASA/MERRA

Earth Engine Snippet

ee.ImageCollection("NASA/GSFC/MERRA/flx/2")

Cadence

1 Hour

Tags

climate merra precipitation sea-salt so2 so4 soil-moisture

Description

M2T1NXFLX (or tavg1_2d_flx_Nx) is an hourly time-averaged 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 meters above ground. The data field is 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.

Bands

Bands

Pixel size: 69375x55000 meters (all bands)

Name	Units	Min	Max	Pixel Size	Description
BSTAR	m/s^2	-0.021035*	0.791739*	69375x55000 meters	Surface buoyancy scale
CDH	kg/m^2/s	8e-06*	0.522482*	69375x55000 meters	Surface exchange coefficient for heat
CDM	kg/m^2/s	5e-06*	0.518079*	69375x55000 meters	Surface exchange coefficient for momentum
CDQ	kg/m^2/s	8e-06*	0.522482*	69375x55000 meters	Surface exchange coefficient for moisture
CN		0.000646*	0.032227*	69375x55000 meters	Surface neutral drag coefficient
DISPH	m	0*	23.0781*	69375x55000 meters	Zero plane displacement height
EFLUX	W/m^2	-308.949*	1655.85*	69375x55000 meters	Total latent energy flux
EVAP	kg/m^2/s	-0.00011*	0.000673*	69375x55000 meters	Evaporation from turbulence
FRCAN		0*	1*	69375x55000 meters	Areal fraction of anvil showers
FRCCN		0*	0.423096*	69375x55000 meters	Areal fraction of convective showers
FRCLS		0*	1*	69375x55000 meters	Areal fraction of nonanvil large scale showers
FRSEAICE		0*	1*	69375x55000 meters	Ice covered fraction of tile
GHTSKIN	W/m^2	-245.078*	1e+15*	69375x55000 meters	Ground heating for skin temperature
HFLUX	W/m^2	-1181.24*	686.742*	69375x55000 meters	Sensible heat flux from turbulence
HLML	m	42.3642*	71.0599*	69375x55000 meters	Surface layer height
NIRDF	W/m^2	0*	282.495*	69375x55000 meters	Surface downwelling nearinfrared diffuse flux
NIRDR	W/m^2	0*	592.217*	69375x55000 meters	Surface downwelling nearinfrared beam flux
PBLH	m	42.3621*	5780.88*	69375x55000 meters	Planetary boundary layer height
PGENTOT	kg/m^2/s	0*	0.017593*	69375x55000 meters	Total column production of precipitation
PRECANV	kg/m^2/s	0*	0.000968*	69375x55000 meters	Anvil precipitation
PRECCON	kg/m^2/s	0*	0.002629*	69375x55000 meters	Convective precipitation
PRECLSC	kg/m^2/s	0*	0.014614*	69375x55000 meters	Nonanvil large scale precipitation
PRECSNO	kg/m^2/s	0*	0.006308*	69375x55000 meters	Snowfall
PRECTOTCORR	kg/m^2/s	0*	0.110565*	69375x55000 meters	Total precipitation
PRECTOT	kg/m^2/s	0*	0.017509*	69375x55000 meters	Total precipitation
PREVTOT	kg/m^2/s	0*	0.001474*	69375x55000 meters	Total column re-evaporation/sublimation of precipitation
QLML		0*	0.034333*	69375x55000 meters	Surface specific humidity
QSH	Mass fraction	0*	0.044069*	69375x55000 meters	Effective surface specific humidity
QSTAR	Mass fraction	-0.000139*	0.005463*	69375x55000 meters	Surface moisture scale
RHOA	kg/m^3	0.658498*	1.68283*	69375x55000 meters	Air density at surface
RISFC		-318.273*	578.05*	69375x55000 meters	Surface bulk Richardson number
SPEEDMAX	m/s	0.074227*	49.4767*	69375x55000 meters	Surface wind speed
SPEED	m/s	0.061141*	49.3541*	69375x55000 meters	Surface wind speed
TAUGWX	N/m^2	-3.06294*	5.8716*	69375x55000 meters	Surface eastward gravity wave stress
TAUGWY	N/m^2	-5.10649*	4.99554*	69375x55000 meters	Surface northward gravity wave stress
TAUX	N/m^2	-5.48865*	5.09378*	69375x55000 meters	Eastward surface stress
TAUY	N/m^2	-6.19036*	4.19191*	69375x55000 meters	Northward surface stress
TCZPBL	m	6.55864*	2.83712e+06*	69375x55000 meters	Transcom planetary boundary layer height
TLML	K	191.833*	320.174*	69375x55000 meters	Surface air temperature
TSH	K	185.73*	328.859*	69375x55000 meters	Effective surface skin temperature
TSTAR	K	-11.0761*	5.74402*	69375x55000 meters	Surface temperature scale
ULML	m/s	-48.8082*	42.8239*	69375x55000 meters	Surface eastward wind
USTAR	m/s	0.000667*	2.31844*	69375x55000 meters	Surface velocity scale
VLML	m/s	-41.9408*	44.3777*	69375x55000 meters	Surface northward wind
Z0H	m	1e-05*	4.54622*	69375x55000 meters	Surface roughness for heat
Z0M	m	1e-05*	4.54622*	69375x55000 meters	Surface roughness

* estimated min or max value

Terms of Use

Terms of Use

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Code Editor (JavaScript)

var dataset = ee.ImageCollection('NASA/GSFC/MERRA/flx/2')
                  .filter(ee.Filter.date('2022-02-01', '2022-02-02'));
var surface_buoyancy_scale = dataset.select('BSTAR');
var sbsVis = {
  min: -0.00998,
  max: 0.01174,
  palette: ['001137', '01abab', 'e7eb05', '620500']
};
Map.setCenter(-95, 39, 2);
Map.addLayer(surface_buoyancy_scale, sbsVis, 'Surface buoyancy scale');

Open in Code Editor

MERRA-2 M2T1NXFLX: Surface Flux Diagnostics V5.12.4

M2T1NXFLX (or tavg1_2d_flx_Nx) is an hourly time-averaged 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 …

NASA/GSFC/MERRA/flx/2, climate,merra,precipitation,sea-salt,so2,so4,soil-moisture

1980-01-01T00:00:00Z/2026-02-01T23:00:00Z

-90 -180 90 180

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