Stratification variability in a lagoon system in response to a passing storm

Abstract

Shallow lagoon systems with limited river flow and precipitation are often regarded as being well-mixed; however, stratification can occasionally occur in shallow lagoons in response to intense river runoffs and precipitation. Understanding the stratification behaviors of a shallow lagoon system is critical for future environmental assessment and management strategies. Thus, in this study, stratification and mixing mechanisms in a shallow lagoon system (the Maryland Coastal Bays) were investigated on an episodic scale during Hurricane Sandy (2012) by using a numerical model. The strength of stratification (Brunt-Väisälä frequency, N in s À1 ) in the lagoon system varied spatially; and was determined by river flow, precipitation, winds, and remote forcing. During the pre-Sandy period (October 25-28, 2012), the bays were relatively mixed without sufficient river flow and precipitation. Driven by intense river flow from the northern creeks (peak: 82.47 m 3 s À1 ), high precipitation (peak: 3.29 Â 10 À6 m s À1 ), and strong storm winds (mean: 12.15 m s À1 ) during the Sandy period (October 28-31, 2012), the water column in the northern creeks of the bays became stratified (mean N 2 : ~0.01 s À2 ). During the post-Sandy period (October 31-November 3, 2012), the St. Martin River among the northern creeks showed strong stratification (mean N 2 : ~0.03 s À2 ) due to weaker winds (mean: 5.70 m s À1 ) and residual high river flow and precipitation from the Sandy period. The wind was found to be the most dominant source of mixing in the bays, while remote forcing and wind regulated the stratification near the Ocean City Inlet.

Modeling Blue Crab (Callinectes sapidus) Larval Transport and Recruitment Dynamics in a Shallow Lagoon‐Inlet‐Coastal Ocean System

“…The salinity limitation is applied only at the releasing stage for blue crab in this work. Given the significant effects of surface winds on salinity changes (Kang & Xia, 2022; Mao & Xia, 2023), calculation of the salinity limitation will be kept in future analysis during the whole larval stages. Considering the ubiquitous influences of climate change (e.g., global warming and sea level rise) on estuarine dynamics in the mid‐Atlantic coastal regions (Najjar et al., 2000), it would be of great interest to predict water circulations and the corresponding blue crab larval transport and recruitment dynamics under the current and future climate change scenarios in a lagoonal system such as the MCBs.…”

“…With enhanced understanding of the hydrodynamics in the MCBs under hurricane and normal conditions (Kang & Xia, 2020, 2022; Kang et al., 2017; Mao & Xia, 2018, 2023), it is worthwhile to explore blue crab larval recruitment dynamics in this unique lagoon–inlet–coastal ocean system. The primary questions raised herein can be summarized as follows: (a) what are the corresponding drifting period and spatial range for the blue crab larvae released under proper water temperature and salinity conditions?…”

Hillsborough bay inflow modification study: An application of the Tampa Bay Coastal Ocean Model

“…TBCOM downscales from the deep-ocean, across the continental shelf and into the estuary by nesting the unstructured grid, Finite Volume Community Model (FVCOM, e.g., Chen et al, 2003), which has been successfully applied in estuarine and coastal systems (e.g., Yuan et al, 2015, Niu et al,2018, Xia et al,2020, Sahoo et al,2021, Kang and Xia, 2022, into the West Florida Coastal Ocean Model (WFCOM, e.g., Zheng and Weisberg, 2012, as modified by Weisberg et al, 2014). WFCOM covers continental shelf region of the eastern Gulf of Mexico, from just west of the Mississippi River Delta to just south of the Florida Keys, by nesting FVCOM in the Gulf of Mexico Hybrid Coordinate Model (GOM-HYCOM, e.g., Chassignet et al, 2009).…”