A New Simulation‐Optimization Framework for Estimation of Submarine Groundwater Discharge Based on Hydrodynamic Modeling and Isotopic Data. Issue 23 (12th December 2022)

• Record Type: Journal Article
• Authors: Yu, Jiang; Tian, Yong; Wang, Xuejing; Wang, Xiaoli; Lancia, Michele; Li, Hailong; Andrews, Charles B.; Zheng, Chunmiao
• Is Part Of: Geophysical research letters. Volume 49:Issue 23(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-12
• Subjects: submarine groundwater discharge -- simulation‐optimization approach -- ocean‐land interactions -- isotopic mass balance modeling; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2022GL098893
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Estimation of submarine groundwater discharge (SGD) has traditionally relied on isotopic mass balance calculation, which is a form of regional box modeling. Here we propose an entirely new approach for SGD estimation by coupling a general marine hydrodynamic simulation model with a global optimization algorithm. The newly developed approach has the distinct advantage of being able to map the spatial distribution of SGD. The results of this study show that the estimated SGD exhibits a strong spatial heterogeneity. Furthermore, this study underscores the important effect of isotope sampling time on SGD estimation. Thus, the fluctuation of seawater level and a lag in isotope activity to water level changes should be considered to assure the representativeness of measured isotope activities. Overall, the simulation‐optimization framework adds a versatile and powerful new tool for more detailed SGD estimation. Plain Language Summary: Discharge of fresh groundwater across the land‐sea interface into the ocean has been recognized as an important process that sustains the health of marine ecosystems. Traditionally, the amount of the submarine groundwater discharge (SGD) is estimated by isotopic mass balance modeling based on the pioneering work of Willard Moore in 1996. However, the isotopic mass balance‐based estimation is subject to regional box modeling. In this study, a new approach is proposed for estimation by coupling a general marine hydrodynamic simulation model with a global optimization algorithm. The newly developed approach has the distinct advantage of being able to map the spatial distribution of SGD. The new approach represents a major advance in estimation of SGD since 1996. Key Points: A new simulation‐optimization framework is developed for submarine groundwater discharge (SGD) study using hydrodynamic modeling and isotopic data The new framework accounts for spatial variation of SGD, not considered in traditional mass balance modeling Seawater isotope sampling should be carefully planned and conducted to reduce uncertainties of SGD estimation