Presentation Details
Indian Ocean intermediate water masses and their simulations by CMIP6 models
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Updated Time：2024-10-11 17:40:28 Hits：824
Poster Presentation
Start Time：2025-01-15 17:20（Asia/Shanghai）
Duration：15min
Session：S60 Session 60-Indian Ocean Dynamics, Air-sea Interaction and Biogeochemical Cycles »
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Abstract
Water masses are carriers of anthropogenic fingerprints in the ocean interior, with their property changes manifesting oceanic thermodynamic responses to climate change. Yet, delimiting ocean water masses remains challenging in either observational atlas or climate models. This study analyzes the distribution of Indian Ocean seawater in the density‐spicity space and uses volumetric maxima and minima between σ = 27.1-27.4 kg m-3 to track the cores and boundaries of intermediate water masses, respectively. In addition to the well-known Antarctic Intermediate Water (AAIW) and Red Sea-Persian Gulf Intermediate Water (RS-PGIW), two other water masses are identified by the new approach. One is the Indian-AAIW (I-AAIW), as a mixture of the AAIW and the Indonesian throughflow water, existing in the South Equatorial Current and the Agulhas Current system. The other (EEIW) exits in the equatorial Indian Ocean and Bay of Bengal, sourced from the RS-PGIW and overlying fresh waters. These waters are corroborated by nutrient and dissolved oxygen data. Around half (26 out of 51) of the Coupled Model Intercomparison Project Phase-6 (CMIP6) models can reasonably simulate these intermediate water masses. Compared with the observed water masses, the intermediate water masses in models are of a smaller thickness, and the RS-PGIW is colder and fresher. The former arises from a warm bias in the thermocline, whereas the latter is likely linked to insufficient ventilation in the Red Sea and Persian Gulf in models owing to coarse grid resolution and a surface cold bias.
Keywords
Indian Ocean; Intermediate water; Potential spicity; Climate models
Speaker
Jihao Zhou
PhD Chinese Academy of Sciences；Institute of OceanologySubmission Author
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Important Date
-
Conference Date
Jan 13
2025
toJan 17
2025
-
Sep 27 2024
Draft paper submission deadline
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Feb 17 2025
Registration deadline
Sponsored By
State Key Laboratory of Marine Environmental Science, Xiamen University
Organized By
State Key Laboratory of Marine Environmental Science, Xiamen University
Department of Earth Sciences, National Natural Science Foundation of China
Department of Earth Sciences, National Natural Science Foundation of China
Contact Information
- Kejing GU
- xm******@xmu.edu.cn
- +86*********
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