The solar and geomagnetic record NRLMSISE-00 reads.

Source      https://kp.gfz-potsdam.de/app/files/Kp_ap_Ap_SN_F107_since_1932.txt
Attribution GFZ German Research Centre for Geosciences and Geomagnetic Observatory Niemegk, CC BY 4.0
Downloaded  2026-10-02
Digest      sha256 cfd3c7dcf021f1d4125f8ecc71a8c5edcb13efe228d111fead95b628e3ba5b4e
            of the file as downloaded, not of the blob next to this note.

Coverage    1957-01-02 to 2026-10-01, 25475 days
            Modified Julian Day 35840 to 61314
            The last day a model can be evaluated on is forty days earlier than the last
            day held, because the 81-day flux average the model wants is centered.

Flux        The observed 10.7 cm radio flux, at the Earth's actual distance from the Sun,
            which is what the model asks for. The flux adjusted to one astronomical unit
            is not kept. 56 of 25475 days were not measured and are
            interpolated from the days either side; they are marked in the blob and
            reported by Day::flux_measured.

Geomagnetic The daily mean Ap and the eight three-hour ap indices. 153 of
            25475 days are definitive rather than preliminary, which Day::definitive
            reports.

Extremes    The flux runs from 53.5 on 1997-03-01 to 938.6 on 2011-03-07.
            Both ends are in the source and are passed through unaltered. The high end is
            real: the daily flux includes radio bursts, so a large flare puts it several
            times above the solar-maximum background, and there are 7 measured
            days above 400. The low end looks like instrument trouble rather than the Sun —
            2 measured days fall below 60, each an isolated day between
            neighbors around 70, and both are in early March. Whether to smooth them is a
            decision for whoever is using the record, not for the record.

Dropped     The sunspot number, which is the one part of the source under CC BY-NC 4.0,
            and the adjusted flux.

Regenerate  scripts/fetch-drivers.py
