  The Earth's primary source of energy is the radiant energy generated by the
Sun, which is referred to as solar irradiance, or total solar irradiance (TSI)
when all of the radiation is measured. A minor change in the solar irradiance
can have a significant impact on the Earth's climate and atmosphere. As a
result, studying and measuring solar irradiance is crucial in understanding
climate changes and solar variability. Several methods have been developed to
reconstruct total solar irradiance for long and short periods of time; however,
they are physics-based and rely on the availability of data, which does not go
beyond 9,000 years. In this paper we propose a new method, called TSInet, to
reconstruct total solar irradiance by deep learning for short and long periods
of time that span beyond the physical models' data availability. On the data
that are available, our method agrees well with the state-of-the-art
physics-based reconstruction models. To our knowledge, this is the first time
that deep learning has been used to reconstruct total solar irradiance for more
than 9,000 years.
