Investigation of hurricane Ivan using the coupled ocean–atmosphere–wave–sediment transport (COAWST) model

2014 ◽  
Vol 64 (11) ◽  
pp. 1535-1554 ◽  
Author(s):  
Joseph B. Zambon ◽  
Ruoying He ◽  
John C. Warner
2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Jing Zou ◽  
Chesheng Zhan ◽  
Haiqing Song ◽  
Tong Hu ◽  
Zhijin Qiu ◽  
...  

In this study, an experimental hydrometeorological forecasting system was developed based on the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) model. The system downloads global real-time ocean, atmosphere, and wave forcing data, producing regional forecasts every day. A coastal area in South China, encompassing Hainan Island, Leizhou Peninsula, and surrounding sea areas, was chosen as the study domain. A series of 72-hour forecasting simulations were conducted in the area, lasting from July 27 to August 31, 2019. The forecasts throughout August were chosen for evaluation with station observations, along with two sets of reanalysis data, ERA5 and CLDAS. The evaluation results revealed that the COAWST model had high potential for routine forecasting operations. The 24 h forecasts, with a lead time of 24 hours, had high accuracy, while the 48 h and 72 h forecasts did not differ greatly in terms of performance. The distributions of bias between forecast and reanalysis data showed obvious differences between land and sea, with more forecasted precipitation and lower temperatures in land grids than in sea grids. In most cases, the forecasts were closer to ERA5 in terms of means and other statistical measures. The forecasts enlarged the land-sea differences of temperature when compared with ERA5 and strengthened summer monsoon with more moisture transported to land areas. Resulting from that, a forecasted bias of lower surface pressure, higher air humidity, stronger south wind, and so forth was also detected over the domain but at low values.


2020 ◽  
Vol 13 (11) ◽  
pp. 5211-5228
Author(s):  
Tarandeep S. Kalra ◽  
Neil K. Ganju ◽  
Jeremy M. Testa

Abstract. The coupled biophysical interactions between submerged aquatic vegetation (SAV), hydrodynamics (currents and waves), sediment dynamics, and nutrient cycling have long been of interest in estuarine environments. Recent observational studies have addressed feedbacks between SAV meadows and their role in modifying current velocity, sedimentation, and nutrient cycling. To represent these dynamic processes in a numerical model, the presence of SAV and its effect on hydrodynamics (currents and waves) and sediment dynamics was incorporated into the open-source Coupled Ocean–Atmosphere–Wave–Sediment Transport (COAWST) model. In this study, we extend the COAWST modeling framework to account for dynamic changes of SAV and associated epiphyte biomass. Modeled SAV biomass is represented as a function of temperature, light, and nutrient availability. The modeled SAV community exchanges nutrients, detritus, dissolved inorganic carbon, and dissolved oxygen with the water-column biogeochemistry model. The dynamic simulation of SAV biomass allows the plants to both respond to and cause changes in the water column and sediment bed properties, hydrodynamics, and sediment transport (i.e., a two-way feedback). We demonstrate the behavior of these modeled processes through application to an idealized domain and then apply the model to a eutrophic harbor where SAV dieback is a result of anthropogenic nitrate loading and eutrophication. These cases demonstrate an advance in the deterministic modeling of coupled biophysical processes and will further our understanding of future ecosystem change.


2017 ◽  
Author(s):  
Christopher R. Sherwood ◽  
Alfredo L. Aretxabaleta ◽  
Courtney K. Harris ◽  
J. Paul Rinehimer ◽  
Romaric Verney ◽  
...  

Abstract. We describe and demonstrate algorithms for treating cohesive and mixed sediment that have been added to the Regional Ocean Modeling System (ROMS version 3.6), as implemented in the Coupled Ocean Atmosphere Wave Sediment-Transport Modeling System (COAWST Subversion repository revision 1179). These include: floc dynamics (aggregation and disaggregation in the water column); changes in floc characteristics in the seabed; erosion and deposition of cohesive and mixed (combination of cohesive and non-cohesive) sediment; and biodiffusive mixing of bed sediment. These routines supplement existing non-cohesive sediment modules, thereby increasing our ability to model fine-grained and mixed-sediment environments. Additionally, we describe changes to the sediment bed-layering scheme that improve the fidelity of the modeled stratigraphic record. Finally, we provide examples of these modules implemented in idealized test cases and a realistic application.


2010 ◽  
Vol 35 (3) ◽  
pp. 230-244 ◽  
Author(s):  
John C. Warner ◽  
Brandy Armstrong ◽  
Ruoying He ◽  
Joseph B. Zambon

2012 ◽  
Vol 43-44 ◽  
pp. 112-137 ◽  
Author(s):  
Maitane Olabarrieta ◽  
John C. Warner ◽  
Brandy Armstrong ◽  
Joseph B. Zambon ◽  
Ruoying He

2018 ◽  
Vol 11 (5) ◽  
pp. 1849-1871 ◽  
Author(s):  
Christopher R. Sherwood ◽  
Alfredo L. Aretxabaleta ◽  
Courtney K. Harris ◽  
J. Paul Rinehimer ◽  
Romaric Verney ◽  
...  

Abstract. We describe and demonstrate algorithms for treating cohesive and mixed sediment that have been added to the Regional Ocean Modeling System (ROMS version 3.6), as implemented in the Coupled Ocean–Atmosphere–Wave–Sediment Transport Modeling System (COAWST Subversion repository revision 1234). These include the following: floc dynamics (aggregation and disaggregation in the water column); changes in floc characteristics in the seabed; erosion and deposition of cohesive and mixed (combination of cohesive and non-cohesive) sediment; and biodiffusive mixing of bed sediment. These routines supplement existing non-cohesive sediment modules, thereby increasing our ability to model fine-grained and mixed-sediment environments. Additionally, we describe changes to the sediment bed layering scheme that improve the fidelity of the modeled stratigraphic record. Finally, we provide examples of these modules implemented in idealized test cases and a realistic application.


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