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Full catalog/M2IUNXLFO
M2IUNXLFO·v5.12.4·dataset

Energy and water hitting the land surface (MERRA-2, daily cycle)

MERRA-2 instU_2d_lfo_Nx: 2d,diurnal,Instantaneous,Single-Level,Assimilation,Land Surface Forcings 0.625 x 0.5 degree V5.12.4 (M2IUNXLFO) at GES DISC
atmosphere NASA GES_DISC Level 4 active
In plain English

What it measures. Describes conditions right at the land surface across the globe, such as air temperature, humidity, and wind just above the ground, broken out for each hour of an average day.

How it's made. Comes from MERRA-2, a NASA reanalysis that blends decades of satellite and other observations into a consistent computer model of the atmosphere, reporting these land-surface values on a roughly half-degree grid.

How & where you'd use it. Useful for studying daily weather rhythms over land and as input for hydrology, agriculture, and energy studies that need a steady, gap-free record back to 1980.

What's measured

ATMOSPHERE › ATMOSPHERIC PRESSURE › SURFACE PRESSUREATMOSPHERE › ATMOSPHERIC TEMPERATURE › SURFACE TEMPERATURE › AIR TEMPERATUREATMOSPHERE › ATMOSPHERIC WATER VAPOR › WATER VAPOR INDICATORS › HUMIDITY › SPECIFIC HUMIDITYATMOSPHERE › ATMOSPHERIC WINDS › SURFACE WINDSATMOSPHERE › ATMOSPHERIC WINDS › SURFACE WINDS › WIND SPEEDATMOSPHERE › ALTITUDE › GEOPOTENTIAL HEIGHT

Coverage & cadence

  • Time span1980-01-01 → ongoing
  • Measured byMERRA-2 (NOT APPLICABLE)
  • Processing levelLevel 4
  • Spatial extent-180, -90, 180, 90
  • StatusACTIVE

What you can do with it

  • Map air pollutants — NO₂, aerosols, ozone
  • Track greenhouse gases and Earth's energy budget
  • Feed weather and air-quality analysis
Official description

M2IUNXLFO (or instU_2d_lfo_Nx) is an instantaneous 2-dimensional monthly diurnal means data collection in Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2). This collection consists of land surface forcing parameters, such as height, specific humidity, wind, and air temperature of the model surface layer. It consists of the monthly mean of the data fields on each hour starting from 00:00 UTC, e.g.: 00:00, 01:00, … , 23:00 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).

Get the data

m2iunxlfo_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="M2IUNXLFO",
    version="5.12.4",
    bounding_box=(-122.5, 37.2, -121.8, 37.9),  # your area (W,S,E,N)
    temporal=("2024-01-01", "2024-12-31"),       # your dates
)
files = earthaccess.open(results)   # stream straight from GES_DISC
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.