Understanding the temporal slope of the temperature-water isotope relation during the deglaciation using isoCAM3: The slope equation

• Published in: Journal of Geophysical Research: Atmospheres
• Main Authors: Guan, Jian, Liu, Zhengyu, Wen, Xinyu, Brady, Esther, Noone, David, Zhu, Jiang, Han, Jing
• Other Authors: Guan, J (reprint author), Peking Univ, Sch Phys, Dept Atmospher & Ocean Sci, Lab Climate Ocean & Atmosphere Studies, Beijing, Peoples R China.; Liu, ZY (reprint author), Univ Wisconsin, Dept Atmospher & Ocean Sci, Madison, WI USA., Peking Univ, Sch Phys, Dept Atmospher & Ocean Sci, Lab Climate Ocean & Atmosphere Studies, Beijing, Peoples R China., Univ Wisconsin, Dept Atmospher & Ocean Sci, Madison, WI USA., Univ Wisconsin, Ctr Climate Res, Nelson Inst Environm Studies, Madison, WI USA., NCAR, Climate & Global Dynam, Earth Syst Lab, Boulder, CO USA., Oregon State Univ, Coll Earth Ocean & Atmospher Sci, Corvallis, OR 97331 USA., Liu, ZY (reprint author), Univ Wisconsin, Dept Atmospher & Ocean Sci, Madison, WI USA.
• Format: Journal/Newspaper
• Language: English
• Published: JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 2016
• Subjects: stable water isotope-temperature relationship; temporal slope; spatial slope; slope equation; LAST GLACIAL MAXIMUM; ICE CORE; CENTRAL GREENLAND; OXYGEN; PRECIPITATION; PALEOTHERMOMETER; RECONSTRUCTION; CONSTRAINTS; CALIBRATION; DELTA-O-18; Greenland; ice core
• Online Access: https://hdl.handle.net/20.500.11897/457527; https://doi.org/10.1002/2016JD024955

The temporal and spatial slopes of water isotope-temperature relations are studied for the last 21,000years over the middle and high latitudes using a series of snapshot simulations of global climate and water isotopes in the isotope-enabled atmospheric model isoCAM3. Our model simulation suggests that both the temporal slope and spatial slope remain largely stable throughout the last deglaciation. Furthermore, the temporal slope can vary substantially across regions. Nevertheless, on average, and most likely, the temporal slope is about 0.3 degrees C-1 and is about half of the spatial slope. Finally, the relation between temporal and spatial slopes is understood using a semiempirical equation that is derived based on both the Rayleigh distillation and a fixed spatial slope. The slope equation quantifies the Boyle's mechanism and suggests that the temporal slope is usually smaller than the spatial slope in the extratropics mainly because of the polar amplification feature in global climate change, such that the response in local temperature at middle and high latitudes is usually greater than that in the total equivalent source temperature. National Science Foundation of China [41130105, 41130962, 41005035]; China Scholarship Council; NSF C2P2; DOE SciDac SCI(E) ARTICLE [e-mail]; [e-mail] 17 10342-10354 121