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This study investigates some of the uncertainties sources associated with the pseudo global warming (PGW) approach which was employed to project future patterns of tropical cyclones (TCs) over the Arabian Sea (AS). First, the climate variables controlling the patterns of tropical cyclones were extracted from reanalysis datasets of ERA5, ERAI, CFSR, and NCEP/NCAR. Then, each dataset was evaluated against long‐term measurements to identify the best‐performing reanalysis dataset. ERA5 showed the best performance for most of the variables. Outputs of 20 CMIP5 global climate models (GCMs) were then evaluated against the ERA5 data resulting in an ensemble of the best performing GCMs. A PGW framework was then used to project the changes in patterns of three significant historical cyclones: Gonu, Phet, and Ashobaa. In doing so, the signals of future climate variables were extracted from the GCMs ensemble to modify the initial and boundary conditions of the WRF model which was previously tuned for reproducing the historical TCs. Different tests were conducted to address the sources of uncertainty in the PGW approach, including the selection of the climate variables contributing to the computation of the signals, the selection of GCMs, and the spatial variation of signals. A considerable sensitivity of the projected track and intensity of TCs to the choice of GCMs was observed, acknowledging the importance of GCMs evaluation before calculating the signals. Moreover, it was found that among all variables, signals of sea surface temperature and air temperature have major effects on the cyclone's track and intensity. Apart from that, when the signals were applied to the domain of the WRF model uniformly, compared to applying spatially varying signals, different tracks and intensities for future TCs were also observed. Overall, the findings of this paper challenge the reliability of the projected changes in TCs patterns obtained from PGW.

Using several series of field measurements data along Iranian coastline of the Persian Gulf and Gulf of Oman, eight different tide models have been evaluated in this study. By comparing the results in the frequency domain, it was found that the model discrepancies arise in shallow waters, having maximum error in the shallowest part of the Persian Gulf, where Pohl station is located. On the other hand, maximum error of tide models is limited to 10 cm in deeper part of the Persian Gulf, indicating that different tide models result in close outcome in deeper waters. Considering the results in the time domain, it was found that FES model, which includes more shallow water constituents, results in better tidal level predictions. FES also presents the best tidal current predictions in the area of the interest of this study.

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Tidal waves have very different dynamics in shallow waters, in comparison to deep sea waters. When a tidal wave approaches to nearshore areas, it might be affected by different factors such as resonance, shoaling in landward direction, funneling due to the decrease of the width, damping due to bottom friction, and partial reflection at abrupt changes of the cross-sections of estuary. Coriolis force can also deflect the tidal waves in large areas, which may lead to the changes of tidal ranges near the coasts. The high increase of tidal range at Musa Bay, located at the north-western part of the Persian Gulf, is studied in this paper. Numerical modeling confirms the occurrence of the resonance for a period of about 8-9 hr., where the amplification factor is gradually decreased with further increase of the wave period. Results implied that resonance, funneling and shoaling are the three most effective parameters which amplify the tide in this area.

The discharge of Arvand River and tidal currents affect the large siltation at Nahre Ghasr Fishery Port, located at the Nahre Ghasr channel, the Persian Gulf. Using 2DH and 3D numerical models, the flow pattern at the channel was investigated to study the details of siltation problem. The local model was calibrated by the measured data of water surface and suspended sediment rate. The main flow mechanisms that can affect the rate of siltation including the horizontal exchange, the vertical exchange and tidal filling, were analyzed. The study showed that tidal filling plays the dominant role on the sedimentation at Nahre Ghasr channel. Different scenarios were also examined for reducing the siltation rate at the port.

<p>Tropical cyclones (TCs) are severe weather marvels, occur in warm tropical waters. These phenomena are among the most influential atmospheric-oceanic events in subtropics regions as the northern part of the Indian Ocean, affecting the Arabian Sea and the Oman Sea, which often cause severe damage to the coastal areas. The interaction between the atmosphere and the upper ocean plays an important role in the structure of TCs, in which successful connections between ocean circulations and the intensity and track of TCs have been identified. TCs derive their energy primarily from the release of latent heat through evaporation and sea spraying in the atmosphere boundary layer. This implies that the presence of a moisture source, with sufficiently warm sea surface temperature (frequently above 26°C) is required to sustain the flux of moisture from the ocean to the atmosphere. The most visible effect of TC passage is the cooling of the sea surface temperature (SST) as the response of the ocean mixed layer (OML) temperature. This decrease in SST has a negative feedback on the intensity of TCs, as it suppresses the heat exchange flux between the atmosphere and the ocean, consequently it can affect the TC track.</p> <p>To investigate the effect of the temperature field on TCs structure, TC Shaheen (2021) with unusual track and entry into the Gulf of Oman is studied. In this regard, Weather Research and Forecasting (WRF) model was used with two different configurations. First, WRF was ran standalone and SST field was only adopted from global models as initial conditions and were not updated during the simulation. Then, as the second configuration, WRF model was coupled with an ocean finite volume model and the SST field was updated online during the simulation. The initial conditions of the ocean temperature, salinity and velocity field were taken from GOFS 3.1 global reanalysis product from the HYCOM Consortium. Primary result for the selected event implies that SST correction during TC simulation with WRF improves air-sea heat flux and has a pronounced effect on the TCs’ intensity and track predictions. Cold wake underside of the TC led to a remarkable heat flux loss from ocean surface into the storm. Hence, the TC size is reduced and the maximum wind speed of the storm is intensified.</p>