[P-EM09_29AM2] VarSITI - Variability of the Sun and Its Terrestrial Impact

[PEM09-35] Modulation of Greenland temperature through changes in solar activity

*Takuro KOBASHI¹, Kenji KAWAMURA¹, Kumiko GOTO-AZUMA¹ (1.National Institute of Polar Reseaerch)

Keywords:solar activity, Greenland, temperature, ice core, climate change

During the past decades, Greenland climate has undergone rapid warming and ice sheet ablation in coastal region with a nearly 1 mm/y sea level contribution. For sea level projection, it is critical to understand the mechanisms of Greenland temperature variability. Greenland temperature is known to be affected by the North Atlantic Oscillation (NAO), and it is also highly correlated with North Atlantic average temperature. Using the Greenland temperature reconstructed from argon and nitrogen isotopes in occluded air in GISP2 ice core (Kobashi et al., 2011), we found Greenland temperature deviated negatively (positively) from North Hemispheric (NH) temperature trend during stronger (weaker) solar activity over the past 800 years (Kobashi et al., 2013b). We also confirmed this effects continued over the past 4000 years (Kobashi et al., 2013a). Climate modeling suggests that the deviation was caused by solar induced atmospheric circulation changes (like NAO). The model also suggests that Atlantic meridional circulation weakens during the stronger sun by similar processes as enhanced greenhouse effect (Kobashi et al., 2013b). From the past relation between Greenland temperature anomaly and solar variability, it can be speculated that future gland solar minimum may induce additional 2 ⁰C warming in Greenland with increased melting of the ice-sheet. Kobashi, T., Kawamura, K., Severinghaus, J. P., Barnola, J.-M., Nakaegawa, T., Vinther, B. M., Johnsen, S. J., and Box, J. E.: High variability of Greenland surface temperature over the past 4000 years estimated from trapped air in an ice core, Geophysical Research Letters, 38, 10.1029/2011GL049444, 2011.Kobashi, T., Goto-Azuma, K., Box, J. E., Gao, C.-C., and Nakaegawa, T.: Causes of Greenland temperature variability over the past 4000 years: Implications for Northern Hemispheric temperature change Climate of the Past, 9, 2299-2317, 2013a.Kobashi, T., Shindell, D. T., Kodera, K., Box, J. E., Nakaegawa, T., and Kawamura, K.: On the origin of Greenland temperature anomalies over the past 800 years, Climate of the Past, 9, 583-596, 2013b.