  An observation-based Galactic Cosmic Ray (GCR) spectral model for heavy
nuclei is developed. Zhao and Qin (J. Geophys. Res. Space Phys.118, 1837(2013))
proposed an empirical elemental GCR spectra model for nuclear charge 5-28 over
the energy range from 30 to 500 MeV/nuc, which is proved to be successful in
predicting yearly averaged GCR heavy nuclei spectra.Based on the latest highly
statistically precise measurements from ACE/CRIS,a further elemental GCR model
with monthly averaged spectra is presented. The model can reproduce the past
and predict the futureGCR intensity monthly by correlating model parameters
with thecontinuous sunspot number (SSN) record. The effects of solar activity
on GCR modulation are considered separately for odd and even solar cycles.
Compared with other comprehensive GCR models, our modeling results are
satisfyingly consistent with the GCR spectral measurements from ACE/SIS and
IMP-8, and have comparable prediction accuracy as the Badhwar & O'Neill 2014
model.A detailed error analysis is also provided.Finally, the GCR carbon and
iron nuclei fluxes for the subsequent two solar cycles (SC 25 and 26) are
predicted and they show a potential trend in reduced flux amplitude, which is
suspected to be relevant to possible weak solar cycles.
