Sentences with phrase «measured irradiance variation»

For the period after 1974, the model makes use of the full - disc magnetograms of the Sun and reproduces up to 97 % of the measured irradiance variation.

Not exact matches

Because of the variations of sunspots and faculae on the sun's surface, the total solar irradiance (TSI), also called the solar constant, varies on a roughly 11 - year cycle by about 0.07 %, which has been measured by orbiting satellites since 1978 [Lean, 1987, 1991; Wilson et al., 1981].

First, this is possible because helioseismic data provide the most precise measure ever of the solar cycle, which ultimately yields more profound physical limits on past irradiance variations.