Characteristics of Extreme Meteorological Forcing and Water Levels in Mobile Bay, Alabama

Abstract

The paper presents comprehensive statistical analyses of winds and water levels in Mobile Bay, Alabama, based on long-term meteorological and tidal observations at several locations. A procedure has been developed to select the most probable parent distribution function from a list of candidate distributions. The theoretical functions that fit the data best enable us to predict the extreme values of winds and water levels at different return periods. We have demonstrated the importance of dividing the winds into hurricane and nonhurricane seasons and separating astronomical tides from weather-driven water level changes. The statistical analysis suggests that the wind speed averaged over 8 min at Dauphin Island, Alabama, at the 100-year return period would be 48.9 m/s, which is equivalent to a sustained 1-min wind of 205 km/h, a very strong category 3 hurricane on the SaffirSimpson scale. The probability distribution models predict that the 100-year maximum water level would be 3.23 m above the mean lower low water (MLLW) level at the bay entrance and 3.41 m above the MLLW level near the head of the bay, respectively. Extremely low water levels important to navigation are also found. Application of the predicted extreme winds and surges is illustrated through the development of a storm wave atlas in the estuary. It is expected that the methodology and results presented in this paper will benefit the management and preservation of the ecosystems and habitats in Mobile Bay.

A Field Study of How Wind Waves and Currents May Contribute to the Deterioration of Saltmarsh Fringe

“…Sea level rise, land subsidence, limited sediment supplies, wind wave impacts on the marsh boundaries and human activities are the main contributors to coastal wetland erosion (e.g., Ganju et al 2013;Leonardi and Fagherazzi 2014). The northern Gulf Coast is subject to frequent, strong wind events due to cold front passages and tropical cyclones (e.g., Zhao and Chen 2008;Chen et al 2008). As wind fetch increases due to the conversion of wetlands to open water, wave power impacting the perimeter of saltmarshes increases.…”

Impacts of Oyster Reef Restoration on Primary Productivity and Nutrient Dynamics in Tidal Creeks of the North Central Gulf of Mexico

“…Only when wind velocities were above the 8 m s −1 threshold did mixing occur and substantial depletion of the water column took place. Since wind velocities are usually low in the north-central Gulf of Mexico (monthly means always <8 m s −1 , Zhao and Chen 2008), it is quite possible that only a small portion of the lower water column regularly came in contact with the oysters on the reef. Several other factors might have contributed to the lack of consistent impacts of created oyster reefs on microalgal Fig.…”

Predicting Impacts of Tropical Cyclones and Sea-Level Rise on Beach Mouse Habitat

“…Following Zhao and Chen (2008), we employed three probability distribution models, namely Log-Normal, Gumbel and Weibull, in the present study. The least-square method is used to fit a two-parameter distribution function to a set of historical data.…”

“…Zhao and Chen (2008) carried out comprehensive statistical analyses of winds and water levels in Mobile Bay based on long-term meteorological and tidal observations at several locations. Zhao and Chen (2008) carried out comprehensive statistical analyses of winds and water levels in Mobile Bay based on long-term meteorological and tidal observations at several locations.…”