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Full catalog/M2TUNXOCN
M2TUNXOCN·v5.12.4·dataset

Daily-cycle averages of ocean surface weather (MERRA-2)

MERRA-2 tavgU_2d_ocn_Nx: 2d,diurnal,Time-Averaged,Single-Level,Assimilation,Ocean Surface Diagnostics 0.625 x 0.5 degree V5.12.4 (M2TUNXOCN) at GES DISC
atmosphere NASA GES_DISC Level 4 active
In plain English

What it measures. Gives long-term averages of ocean-surface conditions broken down by time of day, such as sea-surface temperature and the heat and energy exchanged between ocean and air.

How it's made. Comes from MERRA-2, NASA's reanalysis that blends decades of satellite observations with a weather model to produce a consistent record, here averaged into monthly day-cycle patterns.

How & where you'd use it. Useful for studying how ocean-surface conditions vary through the day and across seasons, and for climate and weather research spanning 1980 to the present.

What's measured

ATMOSPHERE › ATMOSPHERIC RADIATION › HEAT FLUXOCEANS › OCEAN HEAT BUDGET › HEAT FLUXOCEANS › SEA ICE › HEAT FLUXCRYOSPHERE › SEA ICE › HEAT FLUXATMOSPHERE › ATMOSPHERIC RADIATION › LONGWAVE RADIATIONOCEANS › OCEAN HEAT BUDGET › LONGWAVE RADIATIONATMOSPHERE › ATMOSPHERIC RADIATION › SHORTWAVE RADIATIONOCEANS › OCEAN HEAT BUDGET › SHORTWAVE RADIATIONATMOSPHERE › ATMOSPHERIC WATER VAPOR › WATER VAPOR PROCESSES › WATER VAPOR TENDENCYATMOSPHERE › ATMOSPHERIC WATER VAPOR › WATER VAPOR PROCESSES › WATER VAPOR FLUXATMOSPHERE › CLOUDS › CLOUD DYNAMICSATMOSPHERE › CLOUDS › CLOUD MICROPHYSICSTERRESTRIAL HYDROSPHERE › SNOW/ICEATMOSPHERE › PRECIPITATION

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

M2TUNXOCN (or tavgU_2d_ocn_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 ocean surface diagnostics, such as open water skin temperature (sea surface temperature), open water latent energy flux, open water upward sensible heat flux, and open water net downward longwave ( or shortwave ) flux . 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).

Get the data

m2tunxocn_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="M2TUNXOCN",
    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.