Atmospheric CO2 variations on millennial time scales during the early Holocene

• Main Author: 신진화
• Other Authors: 안진호, 자연과학대학 지구환경과학부
• Format: Thesis
• Language: English
• Published: 서울대학교 대학원 2014
• Subjects: CO2; paleoclimate; Siple Dome; ice core; early Holocene; Bond cycle; 550; Pacific; Siple; Southern Ocean; Taylor Dome; EPICA; Ice Sheet; North Atlantic; Sea ice
• Online Access: http://hdl.handle.net/10371/131380

학위논문 (석사)-- 서울대학교 대학원 : 지구환경과학부, 2014. 2. 안진호. The objective of this study is to decipher the relationship between climate and carbon cycles on millennial time scales during the early Holocene. The early Holocene (11.7–7.0 ka) is a climatically dynamic period on millennial timescales as seen in paleoproxy records for ice sheet collapse (Bond Cycle) in the North Atlantic, sea ice extent variations in the Southern Ocean, and El Niño–like and La Niña–like variation in the eastern equatorial Pacific. We may expect atmospheric CO2 concentration change during the early Holocene because CO2 is controlled by physical and biological processes in ocean and land. However, existing CO2 records from EPICA Dome C and Taylor Dome ice cores do not address the issue due to lack of sufficient temporal resolution and chronology. In this study, a new Siple Dome CO2 record for the time period of 9.0-11.7 ka is obtained. Combined with an existing Siple Dome CO2 record for 7.3-9.0 ka, a high-resolution CO2 record for the early Holocene (7.3-11.7 ka) is constructed. The sampling resolution is better than 30 years for 11.7–7.3 ka. The Siple Dome CO2 data show a decrease of CO2 of ~10 ppm from 10.9 to 7.3 ka and multi-centennial to millennial variability of 2-6 ppm with local minima at 11.1, 10.1, 9.0 and 8.3 ka. The millennial-scale CO2 variation correlates with paleoclimate records and show that atmospheric CO2 change was in harmony with global climate change. Possible control mechanisms for CO2 variations are discussed. Abstract Table of contents List of tables List of figures 1. Introduction 1 2. Methods 5 2.1. Siple Dome ice core recovery 5 2.2. Dry gas extraction 5 2.3. Gas Chromatography 7 2.4. Data corrections 9 2.4.1. Blank test 9 2.4.2. Gravitational fractionation effect 10 2.5. Siple Dome chronology 10 3. Results 13 3.1. Data quality 13 3.2. General features 13 3.3. Relationship between climate and CO2 14 4. Climate and carbon cycle 16 4.1. Perturbation in the Southern Ocean 17 4.2. Perturbation in AMOC 19 4.3. El Nio-like and Na Nia-like climate variation 21 5. Discusstion 23 5.1. Comparisons CO2 records among ice cores 23 5.2. Future studies 25 6. Conclusion 28 References 29 Tables 41 Figures 45 Abstract in korean 57 Master