Sea Level Variations and their Relations to the Meteorological Factors in the Arab Gulf Area with Stress on Monthly Means

The hydrographic and meteorological conditions affecting the sea level in the Arab Gulf region have been reviewed. The monthly mean sea level data along the Saudi Arabian coast, relative to Indian Spring Low Water (ISLW) and the atmospheric pressure of eight years from 1980 to 1987 have been analysed spectrally. This indicated that the annual cycle is the main oscillation in both the sea level and pressure records. The oscillations with frequency less than 0.2 cycle/month were coherent. The Fourier analysis of six years data of monthly means showed that the annual cycle has an amplitude of 10-11 cm. The monthly mean sea level in the last two years was calculated using the harmonic simulation and the statistical models relating to the sea level and atmospheric pressure. The comparison between the calculated values and the observed ones in 1986 and 1987 showed reasonable agreement; the harmonic simulation deviated from the observations by about + 5 cm. The influence of the factors other than the atmospheric pressure on the sea level of the study area was found to be positive from June to December and negative from January to April or May, with maximum absolute value of about 11 cm, while the statistical models predict only the pressure effect

Storm Surge Generation by Winter Cyclones at Alexandria, Egypt

The storm surges generated by winter cyclones in the Eastern Mediterranean, at Alexandria coast, are classified according to the synoptic situations. The data used are the hourly sea level values in the western harbour of Alexandria, the atmospheric pressure and the wind velocity at a station nearby the tide gauge during storm periods, from 1971 to 1984. Five types of storm surges were identified. Type A represents the weak surge case with a maximum residual of the order of 12-18 cm. Type B has a maximum residual between 20 and 24 cm. Type C is a moderate surge with an average maximum residual (26-30 cm). Type D has a strong surge, between 35 and 38 cm. Finally, type E has the strongest surge, reaching 43 cm. The depression tracks associated with each type are presented and the observed surges are compared with calculated ones using an equation given by Hamed (1983). A reasonable agreement, with a standard deviation ± 5 cm, was found between observations and calculations

Long-Term Variations of Monthly Mean Sea Level and its Relation to Atmospheric Presssure in the Mediterranean Sea

The monthly mean sea level at 19 stations and the monthly mean atmospheric pressure at 15 stations in the Mediterranean Sea are analysed to find the trend of the sea level and to identify the significant oscillations from the power spectral estimates. The results show that from the present data at Marseille, Trieste and Genova it is expected that the sea level tends to increase by 13 cm /100 years, which will affect the water budget of the area. The spectral analysis of the pressure could explain most of the oscillations in the sea level time series at 12, 6 and 4 months’ periods, except in the Adriatic Sea where the steric effect is expected to have an important contribution

Recentni klimatski trendovi i budući scenariji duž egipatske obale Sredozemlja

This paper analyses the present Egyptian Mediterranean coast (EMC) climate and the response of its climate variables to global changes. First, the accuracy of the ERA-Interim dataset (1979–2010) for the studied region is examined by comparing these data with available independent observations. Second, the qualities of six global climate models (gCMs), together with the ensemble mean of multiple model realisations of the A1B scenario, are examined by comparing these with the ERA-Interim dataset. Finally, gCM simulations are used to describe the uncertainties in future climate change along the EMC. The results indicate that the observations are in good agreement with the ERA-Interim data. The data for the EMC, 1979–2000, display a significant positive trend for 2-m air temperature together with significant negative trends for total precipitation and sea level pressure. The climate model that best de¬scribes the present EMC climate is the CgCM 3.1 model, which is used to describe the future climate of the study area. The CgCM 3.1 model indicates that the EMC area will experience significant warming, substantial droughts, and a weak decrease in sea level pressure in the end of the current century.Ovaj rad analizira sadašnju klimu mediteranskog obalnog područja Egipta (EMC) i odziv odgovarajućih klimatskih varijabli na globalne promjene. Ispitano je podudaranje ERA-Interim baze podataka za razdoblje 1979–2010 za promatrano područje s raspoloživim podacima neovisnih opažanja. Nadalje, usporedbom s ERA-Interim bazom podataka ispitana je pouzdanost šest globalnih klimatskih modela (GCM), zajedno sa srednjakom ansambla višestrukih modelskih realizacija A1B scenarija. Konačno, GCM simulacije su korištene za opisivanje nepouzdanosti u budućoj promjeni klime duž EMC-a. Rezultati pokazuju da se opažanja dobro slažu s ERA-Interim podacima. Podaci za EMC u razdoblju 1979–2010 ukazuju na signifikantni pozitivni trend temperature zraka na 2 m visine, koji je popraćen signifikantnim negativnim trendovima ukupne oborine i tlaka zraka na morskoj razini. Klimatski model koji najbolje opisuje sadašnju EMC klimu je CGCM 3.1, koji je upotrebljen za opisivanje buduće klime razmatranog područja. Model CGCM 3.1 ukazuje na to da EMC područje krajem ovog stoljeća očekuje signifikantno zatopljenje uz značajne suše i blago smanjenje tlaka zraka na razini mora

Recentni klimatski trendovi i budući scenariji duž egipatske obale Sredozemlja

This paper analyses the present Egyptian Mediterranean coast (EMC) climate and the response of its climate variables to global changes. First, the accuracy of the ERA-Interim dataset (1979–2010) for the studied region is examined by comparing these data with available independent observations. Second, the qualities of six global climate models (gCMs), together with the ensemble mean of multiple model realisations of the A1B scenario, are examined by comparing these with the ERA-Interim dataset. Finally, gCM simulations are used to describe the uncertainties in future climate change along the EMC. The results indicate that the observations are in good agreement with the ERA-Interim data. The data for the EMC, 1979–2000, display a significant positive trend for 2-m air temperature together with significant negative trends for total precipitation and sea level pressure. The climate model that best de¬scribes the present EMC climate is the CgCM 3.1 model, which is used to describe the future climate of the study area. The CgCM 3.1 model indicates that the EMC area will experience significant warming, substantial droughts, and a weak decrease in sea level pressure in the end of the current century.Ovaj rad analizira sadašnju klimu mediteranskog obalnog područja Egipta (EMC) i odziv odgovarajućih klimatskih varijabli na globalne promjene. Ispitano je podudaranje ERA-Interim baze podataka za razdoblje 1979–2010 za promatrano područje s raspoloživim podacima neovisnih opažanja. Nadalje, usporedbom s ERA-Interim bazom podataka ispitana je pouzdanost šest globalnih klimatskih modela (GCM), zajedno sa srednjakom ansambla višestrukih modelskih realizacija A1B scenarija. Konačno, GCM simulacije su korištene za opisivanje nepouzdanosti u budućoj promjeni klime duž EMC-a. Rezultati pokazuju da se opažanja dobro slažu s ERA-Interim podacima. Podaci za EMC u razdoblju 1979–2010 ukazuju na signifikantni pozitivni trend temperature zraka na 2 m visine, koji je popraćen signifikantnim negativnim trendovima ukupne oborine i tlaka zraka na morskoj razini. Klimatski model koji najbolje opisuje sadašnju EMC klimu je CGCM 3.1, koji je upotrebljen za opisivanje buduće klime razmatranog područja. Model CGCM 3.1 ukazuje na to da EMC područje krajem ovog stoljeća očekuje signifikantno zatopljenje uz značajne suše i blago smanjenje tlaka zraka na razini mora

Parallelizing Optimal Multiple Sequence Alignment by Dynamic Programming

Optimal multiple sequence alignment by dynamic programming, like many highly dimensional scientific computing problems, has failed to benefit from the improvements in computing performance brought about by multi-processor systems, due to the lack of suitable scheme to manage partitioning and dependencies. A scheme for parallel implementation of the dynamic programming multiple sequence alignment is presented, based on a peer to peer design and a multidimensional array indexing method. This design results in up to 5-fold improvement compared to a previously described master/slave design, and scales favourably with the number of processors used. This study demonstrates an approach for parallelising multi-dimensional dynamic programming and similar algorithms utilizing multi-processor architectures