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IERS EOP C01 Polar Motion, Cleaned, 1846 to 2026

cra:eop-c01-polar-motion-1846-20263,170 records6 columnsv1.0 · issued 2026-07-20
01Description

The complete long polar motion record at 18.26-day sampling, mechanically cleaned: 3,170 epochs of the rotation pole's wobble and drift since 1846, the series behind the observed-record figure on the Association's site, with the methodology notebook that reproduces both the file and the figure.

02Package Contents
Data file (CSV)The cleaned series, one record per row
README.mdSource, terms, exact cleaning steps, column definitions, limitations, citation
Preparation scriptReproduces the CSV mechanically from the named source file(s)
CHECKSUMS.txtSHA-256 for every file in the package
Dataset Recordcra:eop-c01-polar-motion-1846-2026
Series
Earth Orientation
Coverage
1846.0 to 2026.45
Resolution
18.26-day (C01 sampling)
Extent
3,170 records × 6 columns
Version
v1.0 · issued 2026-07-20
Source
IERS EOP C01 (IAU2000), Earth Orientation Centre, Paris Observatory
Package
cra_eop_c01_polar_motion_1846_2026_v1.0.zip · 62 KB
Data file SHA-256
fa42f63b2a8b7a4b1507cb80ecd62d54e00ebcb7a70c1b03bea229e836582a3a
03Drawn from this package
Derived seriesTotal wobble and component envelopes · 1846–2026 · mas
IERS EOP C01 · EOP 20 C04 · Bulletin A (observed)
1920S–30S MINIMUM · 27 MAS1860188019001920194019601980200020200100200300AMPLITUDE, MILLIARCSECONDS
Total wobble (300–500 d band)Chandler (410–470 d)Annual (330–400 d)
Plate I. Total polar wobble amplitude over 180 years with its Chandler and annual component envelopes drawn separately. The dashed rule marks the 1920s–30s minimum of the total envelope at 27 mas; the shaded band marks 2020 onward.Source: IERS EOP C01 · EOP 20 C04 · Bulletin A (observed). Secular pole removed by 6-year mean, Butterworth bandpass, 1-year envelope smoothing. The final year is edge-affected.

Derived from this package together with EOP 20 C04 and Bulletin A, which carry the record forward from 1962 and 1973 respectively. The filter chain is stated on the plate; the three packages together are everything needed to reproduce it.

04Delivery

Resolving member access.

Return to the catalogNext recordIERS EOP 20 C04 Daily Earth Orientation Parameters, 1962 to 2025