Earth Data School
About
Full catalog/M2TUNPUDT
M2TUNPUDT·v5.12.4·dataset

How winds are changing by altitude, daily cycle (model)

MERRA-2 tavgU_3d_udt_Np: 3d,diurnal,Time-Averaged,Pressure-Level,Assimilation,Wind Tendencies 0.625 x 0.5 degree V5.12.4 (M2TUNPUDT) at GES DISC
atmosphere NASA GES_DISC Level 4 active
In plain English

What it measures. How winds at 42 different altitudes are speeding up or slowing down over the course of a typical day, separated into changes caused by large-scale air motion versus small-scale turbulence.

How it's made. Produced by MERRA-2, NASA's model that merges satellite-era observations into a global record, here as monthly averages of the daily wind cycle in 3-hour steps.

How & where you'd use it. A technical resource for atmospheric researchers examining daily wind patterns and how models represent the forces that drive them, rather than for general readers.

What's measured

ATMOSPHERE › ATMOSPHERIC WINDS › WIND DYNAMICSATMOSPHERE › ATMOSPHERIC WINDS › UPPER LEVEL WINDS › WIND DIRECTION TENDENCYATMOSPHERE › ATMOSPHERIC WINDS › UPPER LEVEL WINDS › WIND SPEED TENDENCYATMOSPHERE › ATMOSPHERIC WINDS › SURFACE WINDS › WIND DIRECTION TENDENCYATMOSPHERE › ATMOSPHERIC WINDS › SURFACE WINDS › WIND SPEED TENDENCY

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

M2TUNPUDT (or tavgU_3d_udt_Np) is a 3-dimensional monthly diurnal means data collection in Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2). This collection consists of assimilations of wind tendencies on 42 pressure levels, such as total eastward (or northward) wind analysis tendency, tendency of eastward (or northward) wind due to dynamics, and tendency of eastward (or northward) wind due to turbulence. The information on the pressure levels can be found in the section 4.2 of the MERRA-2 File Specification document. This data collection is the monthly mean of data fields for each 3-hour and time-stamped at the central time starting from 01:30 UTC, e.g.: 01:30, 04:30, … , 22:30 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

m2tunpudt_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="M2TUNPUDT",
    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.