Temporal variability of sea-level in Safaga Harbour, Egypt in relation with meteorological conditions and tidal characteristics

2021 ◽  
Vol 14 (13) ◽  
Author(s):  
Tarek Mohamed El-Geziry ◽  
Amna Salah El-Din Dabbous ◽  
Abdallah Mohamed Abdallah ◽  
Fahmy Mohamed Eid
Ocean Science ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 147-159 ◽  
Author(s):  
Alexander Harker ◽  
J. A. Mattias Green ◽  
Michael Schindelegger ◽  
Sophie-Berenice Wilmes

Abstract. An established tidal model, validated for present-day conditions, is used to investigate the effect of large levels of sea-level rise (SLR) on tidal characteristics around Australasia. SLR is implemented through a uniform depth increase across the model domain, with a comparison between the implementation of coastal defences or allowing low-lying land to flood. The complex spatial response of the semi-diurnal M2 constituent does not appear to be linear with the imposed SLR. The most predominant features of this response are the generation of new amphidromic systems within the Gulf of Carpentaria and large-amplitude changes in the Arafura Sea, to the north of Australia, and within embayments along Australia's north-west coast. Dissipation from M2 notably decreases along north-west Australia but is enhanced around New Zealand and the island chains to the north. The diurnal constituent, K1, is found to decrease in amplitude in the Gulf of Carpentaria when flooding is allowed. Coastal flooding has a profound impact on the response of tidal amplitudes to SLR by creating local regions of increased tidal dissipation and altering the coastal topography. Our results also highlight the necessity for regional models to use correct open boundary conditions reflecting the global tidal changes in response to SLR.


2020 ◽  
Author(s):  
Jacek W. Kaminski ◽  
Joanna Struzewska ◽  
Pawel Durka ◽  
Grzegorz Jeleniewicz ◽  
Marcin Kawka

<p>Benzo[a]pyrene is relatively stable in the atmosphere and can be transported on a regional scale. Benzo[a]pyrene concentrations exceed standard limits in many regions of the world. It is proved that this compound is harmful to the environment and human health.</p><p>According to the CAFÉ Directive (2008/50/EC), the objective is to achieve a concentration of B[a]P below 1ng/m3 in PM10 aerosol. Observed B[a]P concentration in Poland is among the highest in Europe. These exceedances are attributed to the emission from individual heating, where many old installations are still in operation. Major B[a]P emissions are due to low-quality fuels and non-reported municipal waste burning.</p><p>To support the Chief Inspectorate of Environmental Protection in the frame of the annual assessment for 2018 and five-year assessment for the period 2014-2018, the spatial distribution of B[a]P was calculated using the GEM-AQ model (Kaminski et al. 2008). A new national high-resolution bottom-up emission inventory was used for the entire area of Poland. The results at the resolution of 2.5 km were compared with observations from over 100 stations from the National Measurement Network. We will discuss the spatial and seasonal variability od B[a]P concentrations as well as year-to-year changes related to meteorological conditions.</p><p> </p>


2018 ◽  
Author(s):  
Alexander Harker ◽  
J. A. Mattias Green ◽  
Michael Schindelegger

Abstract. An established tidal model, validated for present-day conditions, is used to investigate the effect of large levels of sea-level rise (SLR) on tidal characteristics around Australasia. SLR is implemented through a uniform depth increase across the model domain, with a comparison between the coastal boundary being treated as impenetrable or allowing low-lying land to flood. The complex spatial response of the semi-diurnal constituents, M2 and S2, is broadly similar, with the magnitude of M2's response being greater. The most predominant features of this response are large amplitude changes in the Arafura Sea and within embayments along Australia's north-west coast, and the generation of new amphidromic systems within the Gulf of Carpentaria and south of Papua, once water depth across the domain is increased by 3 and 7 m respectively. Dissipation from M2 increases around the islands in the north of the Sahul shelf region and around coastal features along north Australia, leading to a notable drop in dissipation along Eighty Mile Beach. The diurnal constituent, K1, is found to be amplified within the Gulf of Carpentaria, indicating a possible change of resonance properties of the gulf. Coastal flooding has a profound impact on the response of tidal amplitudes to SLR, particularly K1, by creating local regions of increased tidal dissipation and altering the shape of coastlines.


Author(s):  
U. V. Prokhorova ◽  
P. N. Sviashchennikov ◽  
B. V. Ivanov

The article presents the results of a study of the temporal variability of atmospheric circulation in the Arctic region. The classifi cation of atmospheric circulation forms according to Wangenheim — Girs for cold (November – April) and warm (March – October) periods of the year are used. We consider the repeatability of series with one form of circulation for gradations of duration and variability in time of this characteristic, as a parameter of stability of synoptic processes in the region under consideration. As additional characteristics, the horizontal gradients of the pressure field are calculated according to the atmospheric pressure at sea level. Estimates of the variability of the meridional and latitudinal directions of air advection are obtained.


2011 ◽  
Vol 24 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Juan Vidal ◽  
Manuel Berrocoso ◽  
Alberto Fernández-Ros

AbstractDuring the 2007–08 Spanish Antarctic campaign, two moorings of bottom pressure sensors were carried out over a ten week period. This paper presents the results of the tidal analysis from sea level records obtained at Deception and Livingston islands (South Shetland Islands, Antarctica). The main objective of this paper is to present a detailed study of the tidal characteristics at these two islands, for which statistical and harmonic analysis techniques are applied to the tidal records. A geodetic network was used to reference the pressure sensors. Geometric levelling, with an accuracy of 1 mm, allowed us to link the tidal marks with geodetic vertices located on Livingston and Deception islands. The amplitudes and phase lags obtained by harmonic analysis are compared to the harmonic constants of several coastal stations and co-tidal and co-range charts. Results show an evident influence of tides in the sea level signal, with a clear mixed semi-diurnal behaviour and a daily inequality between high and low waters. Measurements of salinity and temperature were made using electronic sensors. Results from this study showed that salinity and temperature were strongly influenced by tides. Seawater temperature varied in a manner that was consistent with the time series of residual bottom pressure.


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