Storm surge modeling in the Caspian Sea using an unstructured grid (original) (raw)
Related papers
Storm Surges and Extreme Wind Waves in the Caspian Sea in the Present and Future Climate
Civil Engineering Journal
The Caspian Sea is of particular interest. Against the background of long-term sea level changes, low-lying coastal areas in the northern part are subject to constant flooding as a result of storm surges. The elongation of the sea in the meridional direction allows the development of strong waves in the middle and southern parts. A comprehensive understanding of the characteristics of storm surges and storm waves is especially important in the context of ongoing climate change. This study is devoted to the analysis of storm surges for the time period from 1979 up to 2017 and wind waves from 1979 to 2020 in the Caspian Sea region. The circulation model ADCIRC and the wave model WAVEWATCH III with wind and pressure forcing from the NCEP/CFSR reanalysis were used. The modeling is performed on different unstructured grids with spacings of 500–900 m in the coastal zone. Mean and extreme values of surges, wave parameters and storm activity are provided in the research. The maximum signifi...
Storm surges and storm wind waves in the Caspian Sea in the present and future climate
This study is devoted to the analysis of the storm surges and wind waves in the Caspian Sea for the period from 1979 to 2017-2020. The models used are the circulation model ADCIRC and the wave model WAVEWATCH III with wind and pressure forcing from the NCEP/CFSR reanalysis. The modeling is performed on the unstructured grid with spacing to 300-700 m in the coastal zone. Mean and extreme values of surges, wave parameters, and storm activity are provided. The maximum significant wave height for the whole period amounts to 8.2 m. The average long-term SWH does not exceed 1.1 m. No significant trend in the storm activity was found. The maximum surges height amounts to 2.7 m. Analysis of the interannual variability of the surges occurrence showed that 7-10 surges with a height of more than 1 meter were obtained per year and the total duration all these surges was 20-30 days per year. Assessment of the risk of coastal flooding was carried out by calculating the extreme values of the Sea for different return periods 5, 10, 25, 50, and 100 years. The extreme sea level values in the northern part of the Caspian Sea for the return period 100 years is close to 3 m and the areas with big surges are located along the eastern and western coasts. Based on climatic scenarios of CMIP5, a forecast is made for the recurrence of storm wind waves in the 21st century. A statistically significant increase of storm waves recurrence in future was found, but it is not dramatically growing.
Investigation of Atmospheric Conditions Associated with a Storm Surge in the South-West of Iran
Atmosphere, 2021
Severe thunderstorms are often accompanied by strong vertical air currents, temporary wind gusts, and heavy rainfall. The development of this atmospheric phenomenon over tropical shallow water zones, such as bays, can lead to intensification of atmospheric disturbances and produce a small-scale storm surge. Here, the storm surge that occurred on 19 March 2017 in the Persian Gulf coastal area has been investigated. Air temperature, precipitation, mean sea level pressure, wave height, wind direction, wind speed, geopotential height, zonal components, meridional winds, vertical velocity, relative humidity, and specific humidity obtained from the European Centre for Medium-Range Weather Forecasts (ECMWF) and Global Forecast System (FNL) were used to implement the Weather Research and Forecasting (WRF) model. The results showed that the main cause of the storm surge was the occurrence of a supercell thunderstorm over the Persian Gulf. The formation of this destructive phenomenon resulted from a downburst under Cumulonimbus cloud and high-velocity air subsidence, after collision with the sea surface coinciding with the high tide. This caused a severe, yet temporary, gust, which in turn caused the creation of the four waves of 3.1 m height along the coast of Bandar Dayyer.
Evaluation of Different Wind Fields for Storm Surge Modeling in the Persian Gulf
Journal of Coastal Research
With the increasing demand for accurate storm surge predictions in coastal regions, there is an urgent need to select the most accurate wind field product to use in hydrodynamic prediction models. In this study, the responses of a coastal and ocean circulation model (FVCOM) to four wind products, QuikSCAT, ECMWF ERA-Interim, GFS, and CCMP, were evaluated. Simulations of water level fluctuation with the mentioned wind forcings were compared with the tide gauge observations in the northern part of the Persian Gulf. The results show that using GFS wind field, which is a global numerical weather prediction model, produce better results compared with using other wind data sets. Although the result shows competitive improvement of the storm surge prediction between GFS and CCMP forced model, the former one excels the results almost in all stations. Root mean square error parameter of GFS forced-model for Kangan tide gauge station is 0.80 compared with those of QuikSCAT, ECMWF, and CCMP which are 0.64, 0.73, and 0.79, respectively.
Coastal Storm Surge Analysis: Computational System, Report 2: Intermediate Submission No. 1.2
2011
The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. All product names and trademarks cited are the property of their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents.
Storm Surges: Phenomena, Forecasting and Scenarios of Change
Precedia IUTA , 2012
Storm surges are behind the geophysical risk of short term and abrupt inundating low‐lying coastal regions known along most coasts of the world. They are related to meteorological phenomena, mostly wind storms. Storm surges represent a challenge for science and risk management with respect to short term forecasts of specific events but also with long‐term changes of the statistics of storm surges due to anthropogenic global climate change, sinking coasts and estuarine water works. Storm surges are expected to become more severe in the coming decades and centuries because of ongoing and expected accelerated mean sea level, and much less so because of more energetic wind storms. A related article is von Storch, H. and K. Woth, 2008: Storm surges, perspectives and options. Sustainability Science 3, 33-44; DOI 10.1007/s11625-008-0044-2
Natural Hazards, 2009
Both finite-element and finite-difference numerical models are applied to simulate storm surges and associated currents generated by tropical cyclones that struck the coast of Andhra Pradesh, located on the east coast of India. During a cyclone, the total water level at any location on the coast is made up of the storm surge, surge-wind wave interaction and the tide. The advanced circulation two-dimensional depth-integrated (ADCIRC-2DDI) model based on finite-element formulation and the two-dimensional finite-difference model of storm surges developed at IIT Delhi, hereafter referred as IITD storm surge model, are used. These models are driven by astronomical tides at the open ocean boundary and cyclonic asymmetric winds over the surface of the computational domain. Comparison of model simulated sea-surface elevations with coarse and finer spatial resolutions suggests that the grid resolution near the coast is very crucial for accurate determination of the surges in addition to the local bathymetry. The model underpredicts surges, and the peak surge location shifts more to the right of the landfall as the spatial resolution of the model becomes coarser. The numerical experiments also demonstrate that the ADCIRC model is robust over the IITD storm surge model for surge computations as the coastline is better represented in the former.
A numerical modelling study of storm surges in Bass Strait
Australian Meteorological Magazine, 2003
Strait is investigated. The sustained westerly or southwesterly winds that accompany cold fronts along the south coast are found to be the most common cause of storm surges, although the intensification of low pressure systems in Bass Strait can also produce surges in this region, T\vo events, caused by cold fronts, are modelled using a high-resolution coastal ocean model. The storm surges produced by meteorological forcing show close agreement with observations at stations west of Bass Strait. In Bass Strait, measured sealevel residuals during strong westerly wind events exhibit a semi-diurnal oscillation resulting from an approximate 20 minute delay between the measured high tides and the predicted tides used to extract the sealevel residuals. This delay can be reproduced by the model when run with atmospheric and tidal forcing and the tides subsequently removed, indicating that the enhanced westerly current during the surge event interacts with the tidal currents to produce a temporary phase delay in the fides in western Bass Strait, although the physical mechanism behind the response is not clear. The contribution to storm surge height due to atmospheric pressure is found to be only around 10 per cent of the inverse barometer effect indicating that wind stress is by far the dominant component of the storm surge height in this region, The role of remote and local wind forcing in Bass Strait is investigated by performing model simulations where the western boundary of the model domain is moved progressively eastwards. Exclusion of the narrow shelf region immediately to the west of Bass Strait reduces the peak surge within Bass Strait by between 50 and 80 per cent in broad agreement with theoretical studies. An investigation of the effect of wind speed changes on storm surge height reveals that storm surge height responds linearly to changes in wind strength with a proportionality coefficient of around two.