Direct Influence of Solar Spectral Irradiance on the High-Latitude Surface Climate

Abstract Not only total solar irradiance (TSI) but also spectral (SSI) matter for our climate. Different surfaces can have different reflectivity the visible (VIS) and near-infrared (NIR). The recent NASA Total Spectral Solar Irradiance Sensor (TSIS-1) mission has provided more accurate SSI observations than before. TSI observed by TSIS-1 differs from counterpart used climate models no 1 W m −2 . However, difference in a given VIS (e.g., 0.44–0.63 μ m) NIR 0.78–1.24 band be as large 4 with opposite signs. Using NCAR CESM2, we study to what extent such partitions affect simulated Two sets of simulations identical are carried out, one partitioning other been current models. Due VIS-NIR reflectance contrasts between icy (or snowy) open water, simulation less absorption high-latitude surfaces, ending up colder polar surface temperature larger sea ice coverage. is prominent over Antarctic Arctic. Our results suggest that, even TSI, albedo feedback triggered partition NIR. underscore importance continuously monitoring use correct simulations.