  Solar flares result in an increase of the solar irradiance at all
wavelengths. While the distribution of the flare fluence observed in coronal
emission has been widely studied and found to scale as f(E) ~ E^{-\alpha}, with
\alpha slightly below 2, the distribution of the flare fluence in chromospheric
lines is poorly known. We used the solar irradiance measurements observed by
the SDO/EVE instrument at a 10s-cadence to investigate if there is a dependency
of the scaling exponent on the formation region of the lines (or temperature).
We analyzed all flares above the C1 level since the start of the EVE
observation (May 2010) to determine the flare fluence distribution in 16 lines
covering a large range of temperature, several of which were not studied
before. Our results show a small downward trend with the temperature of the
scaling exponent of the PDF, going from above 2 at lower temperature (a few
10^4 K) to about1.8 for hot coronal emission (several 10^6 K). However, because
colder lines also have smaller contrast, we could not exclude that this
behavior is caused by including more noise for smaller flare for these lines.
We discuss the method and its limits and tentatively associate this possible
trend to the different mechanisms responsible for the heating of the
chromosphere and corona during flares.
