Relative transparency of sea water in the Green-fjord Bay (Spitsbergen)

2017 ◽  
Vol 7 (2) ◽  
pp. 144-150
Author(s):  
Boris Viacheslavovich Ivanov
Keyword(s):  
Sea Water ◽  
Time Variability ◽  
Research Station ◽  
Relative Transparency ◽  
External Conditions

The results of the analysis of spatial-time variability of relative transparency (depth of disappearance of a standard white Sechi disk) in the Green-fjord Bay (Spitsbergen archipelago) are presented. The data covers the period from 1986 to 1990 and were obtained during carrying- out of the oceanographic monitoring by experts of Barentsburg research station (Murmansk HydroMeteorogical Management) in frame of the program of standard coastal supervision. Some conclusions about the reasons of spatial and time variability of relative transparency depending from change of external conditions are presented.

CO2 and H+ Excretion by Swimming Coho Salmon, Oncorhynchus Kisutch

1983 ◽  
Vol 107 (1) ◽  
pp. 169-180
Author(s):  
GUIDO VAN DEN THILLART ◽  
DAVID RANDALL ◽  
LIN HOA-REN
Keyword(s):  
High Speed ◽  
Coho Salmon ◽  
Sea Water ◽  
Oncorhynchus Kisutch ◽  
Hydrogen Ion ◽  
Ion Transfer ◽  
Bicarbonate Concentration ◽  
Seawater Ph ◽  
External Conditions ◽  
Co2 Excretion

Coho salmon, Oncorhynchus kisutch (Walbaum), were swum at constant speed in a ‘Brett-type’ tunnel respirometer. Blood PO2, PCO2 and pH as well as total CO2 content and red blood cell pH were unchanged during swimming. The RE (respiratory exchange ratio) was slightly less than 0.7 when the fish was swimming in normal sea water, indicating that some CO2 retained by the fish. Lowering seawater bicarbonate concentration increased HCO3− transfer, presumably because of passive bicarbonate loss. A reduction in seawater pH from 7.95 to 7.1 sharply reduced both CO2 and hydrogen ion transfer, resulting in very low RE values of about 0.2. Hydrogen ion excretion was elevated during prolonged swimming following high speed swimming activity. It would appear that CO2 and hydrogen ion transfer by fish need not be matched and changing internal and external conditions can have a marked and separate effect on hydrogen ion and CO2 excretion and therefore on the RE value.

A Virtual Geostationary Ocean Colour Sensor to characterise the river-sea interaction over the North Adriatic Sea.

2020 ◽  
Author(s):  
Marco Bracaglia ◽  
Rosalia Santoleri ◽  
Gianluca Volpe ◽  
Simone Colella ◽  
Federica Braga ◽  
...  
Keyword(s):  
Adriatic Sea ◽  
Sea Water ◽  
Interdisciplinary Studies ◽  
Time Variability ◽  
Spatial And Temporal Variability ◽  
Ocean Colour ◽  
The North ◽  
Uncertainty Sources ◽  
Short Time ◽  
North Adriatic Sea

<p>Inherent optical properties (IOPs) and concentrations of the sea water components are key quantities in supporting the monitoring of the water quality and the study of the ecosystem functioning. In coastal waters, those quantities have a large spatial and temporal variability, due to river discharges and meteo-marine conditions, such as wind, wave and current, and their interaction with shallow water bathymetry. This short term variability can be adequately captured only using Geostationary Ocean Colour (OC) satellites, absent over the European seas.</p><p>In this study, to compensate the lack of an OC geostationary sensor over the North Adriatic Sea (NAS), the Virtual Geostationary Ocean Colour Sensor (VGOCS) dataset has been used. VGOCS contains data from several OC polar satellites, making available multiple images a day of the NAS, approaching the temporal resolution of a geostationary sensor.</p><p>Generally, data from different satellite sensors are characterized by different uncertainty sources and consequently, looking at two satellite images, it is not easy to ascertain how much of the observed differences are due to real processes. In the VGOCS dataset, the inter-sensor differences are reduced, as the satellite data were adjusted with a multi-linear regression algorithm based on in situ reflectance acquired in the gulf of Venice. Consequently, the use of the adjusted spectra as input in the retrieval of the IOPs and the concentrations allows performing a reliable analysis of the short-time bio-optical variability of the basin.</p><p>In this work, we demonstrate the suitability of VGOCS to better characterise the river-sea interaction and to understand the influence of the river forcing on the short time variability of IOPs and concentrations in the coastal areas. This variability will be analysed for different case studies characterised by a different regime of river discharges, using meteorological, hydrological, and oceanographic fields as ancillary variables. This new approach and the availability of this new set of data represent an opportunity for interdisciplinary studies, in support to and interacting also with modelling implementations in river-sea areas.</p>

scholarly journals DINAMIKA PERUBAHAN GARIS PANTAI DI PESISIR DESA SURODADI KECAMATAN SAYUNG DENGAN MENGGUNAKAN CITRA SATELIT (Dynamics of Coastal Line Changes in the Surodadi Village of Sayung Sub District by Using Satellite Imagery)

2018 ◽  
Vol 6 (4) ◽  
pp. 433-441
Author(s):  
Aulia Huda Riyanti ◽  
Agung Suryanto ◽  
Churun Ain
Keyword(s):  
Remote Sensing ◽  
Land Cover ◽  
Sea Water ◽  
Satellite Image ◽  
Remote Sensing Data ◽  
Image Data ◽  
Rate Of Change ◽  
Research Station ◽  
Shoreline Changes ◽  
Coastline Change

Garis pantai Desa Surodadi mengalami perubahan dari tahun ke tahun. Perubahan yang serius ini perlu untuk dilakukan pemantauan terus menerus. Penelitian ini dilakukan untuk memperoleh informasi tentang perubahan garis pantai dan kaitannya dengan tutupan lahan di pesisir Desa Surodadi Kecamatan Sayung Kabupaten Demak pada tahun 2015 dan 2016. Penelitian ini dilaksanakan pada bulan Mei sampai dengan Juni 2017. Stasiun penelitian dibagi menjadi lima stasiun berdasarkan lokasi abrasi dan akresi yang telah terjadi. Dengan proses overlay kedua data citra satelit melalui sistem informasi geografis merupakan cara cepat untuk mengetahui perubahan garis pantai yang terjadi pada pesisir Desa Surodadi. Metode penelitian ini dengan menggunakan metode deskriptif studi kasus dengan menggunakan teknologi penginderaan jauh pada pengolahan data citra SPOT 6 tahun 2015 dan tahun 2016 yang diperoleh dari Pusat Teknologi dan Data Penginderaan Jauh LAPAN Jakarta serta dilakukan survei lapangan sehingga diperoleh laju perubahan garis pantai serta tutupan lahan yang terdapat pada lokasi penelitian. Garis pantai yang terjadi dari tahun 2015 sampai tahun 2016 lebih banyak mengalami proses abrasi jika dibandingkan proses akresi. Berdasarkan hasil penelitian dapat diketahui laju perubahan panjang garis pantai sebesar 103,58 m, perubahan garis pantai yang terjadi berupa abrasi sebesar 1,197 ha dan perubahan yang berupa akresi sebesar 0,490 ha. Keterkaitan antara perubahan garis pantai dengan tutupan lahan di Desa Surodadi adalah tutupan mangrove yang ada cukup luas dan relatif rapat sehingga dapat mencegah intrusi air laut yang dapat menyebabkan perubahan garis pantai. Surodadi village coastline changes from year to year. This serious change is necessary for ongoing monitoring. This research was conducted to obtain information about coastline change and its relation to land cover in coastal village of Surodadi Sub-District of Sayung Regency of Demak in 2015 until 2016. This research was conducted from May to June 2017. The research station is divided into five stations based on the location of abrasion and Accretion that has occurred. With the second overlay process satellite image data through geographic information system is a quick way to find out the shoreline changes that occur in the coastal village of Surodadi. This research method is done by using descriptive method of case study by using remote sensing technology on SPOT image data processing of 6 year 2015 and year 2016 which obtained from Center of Technology and Remote Sensing Data of LAPAN Jakarta and conducted field survey so that obtained rate of change of coastline happened also Land cover located at the research location. Coastlines that occur from 2015 to 2016 more experienced abrasion process when compared to the accretion process. Based on the research results can be seen the rate of change of coastline length of 103.58 m, shoreline changes that occur in the form of abrasion of 1.197 ha and changes in the form of accretion of 0.490 ha. The link between coastline change and land cover in Surodadi Village is that the mangrove cover is wide enough and relatively close so it can prevent the intrusion of sea water which can cause coastline changes.

scholarly journals STRUKTUR KOMUNITAS LARVA IKAN PADA SAAT PASANG SURUT DI MUARA SUNGAI MOROSARI SAYUNG, DEMAK

2018 ◽  
Vol 7 (4) ◽  
pp. 370-378
Author(s):  
Prayogi Pahingguan ◽  
Bambang Sulardiono ◽  
Wiwiet Teguh Taufani
Keyword(s):  
Sea Water ◽  
Fish Larvae ◽  
Diversity Index ◽  
Research Result ◽  
High Tide ◽  
River Estuary ◽  
Survey Method ◽  
Research Station ◽  
Tide Level ◽  
Index Value

Muara Sungai merupakan perairan semi tertutup yang terletak di bagian hilir sungai dan masih berhubungan dengan laut sehingga memungkinkan untuk terjadinya pencampuran dua massa air, yakni air tawar dan air laut. Tujuan penelitian untuk mengetahui komposisi dan kelimpahan larva ikan, mengetahui perbedaan struktur komunitas pada saat pasang dan surut. Metode yang di gunakan adalah metode survei yang dilaksanakan pada bulan Mei 2018 di Muara sungai Morosari Sayung, Demak. Sampling dilakukan pada 3 stasiun dengan kondisi pasang dan surut. Variabel yang diukur antara lain Komposisi, Kelimpahan Larva ikan dan Struktur komunitas pada saat pasang dan surut. Hasil penelitian didapatkan Larva ikan pada saat pasang di stasiun I sebanyak 43 ind, stasiun II diperoleh larva  ikan sebanyak 22 ind dan stasiun III sebanyak 34 ind. Hasil penelitian didapatkan pada saat surut di stasiun I sebanyak 24 ind, stasiun II 22 ind dan stasiun III sebanyak 34 ind. Keseluruhan larva ikan yang tertangkap terdiri dari 10 famili yaitu Nemipteridae, Mugilidae, Gobiidae, Ambassidae, Acrididae, Chanidae, Engraulidae, Labridae, Scatophagidae dan Lactaridae. Indeks keanekaragaman pada saat pasang termasuk dalam kategori rendah dan sedang dengan nilai berkisar 0,99-1,6. Indeks keseragaman berkisar antara 0,78-0,91 maka tergolong kedalam kategori tinggi atau stabil. Nilai indeks Dominasi termasuk kedalam dominasi rendah dan sedang dengan nilai berkisar antara 0,22-0,40. Nilai indeks keanekaeragaman pada saat surut masuk dalam kategori rendah dan sedang dengan nilai berkisar 0,91-1,41. Indeks keseragaman berkisar 0,66-0,91 masuk dalam kategori stabil. Dominasi berkisar antara 0,32-0,45, dengan nilai tersebut maka dapat dikategorikan Dominasi sedang.  Estuary is a semi-closed waters located in the downstream part of the river and still in contact with the sea, allowing for mixing of two water masses, namely fresh water and sea water. The purpose of this research is to find out the composition and abundance of fish larvae, to know the differences in community structure during high and low tide levels. The method used in this research is a survey method conducted in May 2018 in the river estuary of Morosari Sayung, Demak. Sampling was carried out at 3 tidal and low tide stations. Variables measured include Composition and Abundance of fish larvae and community structures during highs and low tide level. The research result showed that 43 ind larvae at high tide at station I, were 22 ind at stations II, were obtained and 34 ind stations III. The results of the research were obtained at low tide at station I as many as 24 ind, station II 22 ind and station III as many as 34 ind. All captured fish larvae consist of 10 families namely Nemipteridae, Mugilidae, Gobiidae, Ambassidae, Acrididae, Chanidae, Engraulidae, Labridae, Scatophagidae and Lactaridae. The diversity index value at the high tide entered in the low and medium category ranged from 0.99 to 1.6. Uniformity lindex ranges from 0.78 to 0.91 in the medium category. Domination ranges from 0.22 to 0.40, with this value the entire research station into the category there is no dominance. The diversity index value at the low tide entered in the low and medium category ranged from 0.91 to 1.41. The uniformity index ranges from 0.66 to 0.91 included in the stable category. Domination ranges from 0.32-0.45 with this value can be categorized medium. 

Water resources management - England and Wales

1972 ◽  
Vol 180 (1061) ◽  
pp. 367-369
Keyword(s):  
Water Pollution ◽  
Water Resources ◽  
Sea Water ◽  
Research Station ◽  
Research Association ◽  
Land Drainage ◽  
Quality Of Water ◽  
Pollution Research ◽  
Considerable Impact ◽  
The Impact

I would like to congratulate the Royal Society on the choice of subject for this symposium, and hope that it will provide a sufficient development of a consensus to have influence on the solution to the problems now being widely canvassed. I read ‘industry’ in its widest sense, including local authorities and farmers among those who influence the quality of water in rivers and estuaries. It would be impossible to split the problem between the various component activators. In the overall management of the water pollution and water resources problem a large number of Government Departments are involved: The Department of Education and Science, with its responsibility for the Natural Environment Research Council; the Department of the Environment, with its own special Water and Sewerage Division, and its responsibility for the Water Resources Board, Water Pollution Research Laboratory, Hydraulics Research Station and the Water Research Association in partnership with the water supply industry; the Ministry of Agriculture, Fisheries and Food is interested in the land drainage and both fresh- and sea-water fisheries; and the Minister of Power through the Central Electricity Generating Board is the largest user of water, having a considerable impact on the flow régime of rivers and the temperature of the water. In due course, when the problems of the pollution of the sea are studied in more detail, the impact of river and estuary pollution on the adjacent seas will need quantitative study. In this case, there are grave dangers at present of over-stating the problems and the distinction between awareness and need for action needs to be borne carefully in mind.

scholarly journals XIII. The effect of environment on the development of echinoderm larvœ: an experimental inquiry into the causes of variation

1895 ◽  
Vol 186 ◽  
pp. 577-632 ◽  
Keyword(s):  
Soft Tissues ◽  
Sea Water ◽  
Sea Urchins ◽  
The Body ◽  
Supernatant Liquid ◽  
Long Time ◽  
External Conditions ◽  
Mechanical Stage ◽  
The Subject ◽  
Maximum Development

The influence of external conditions upon the growth and development of plants and animals has been known for a very long time, and has been made the subject of careful observation by many horticulturists and breeders, in addition to those who have attacked the problem in a more scientific spirit. As a rule, the changed conditions of environment, of which the effects were to be observed, were very considerable, and not such as might occur in nature, and the effects produced were not generally subjected to exact measurement. It seemed of interest, therefore, to determine as exactly as possible by measurement the effects which such slight changes in environment, as might occur under natural conditions, would produce in the growth of some organism, with a view to ascertaining how far the variations in size and relation of parts which occur in all animals may be caused by these external conditions, apart from such variations which arise from intrinsic differences in the germ. The animal chosen lor this purpose was the larva or pluteus of the sea-urchin, StroJigylocentrotus lividus. These larvae have the merit of being very hardy, and they develop readily from artificial fertilisations without any special precautions being taken. Moreover, it was found that these artificial fertilisations could be effected at all times of the year, irrespective of season. The chief objection to the choice of this animal lies in the fact that the growth of the larvae cannot be carried to the adult stage, so that it is only possible to measure the effect of environment at a particular period in their development. The plan of operations was very simple. About six or eight sea-urchins, which, as a rule, had been freshly obtained the same morning, were cut open, and pieces of the ovaries of each of the three or four female specimens shaken with forceps in a small jar of sea-water. Pieces of the testes were shaken in another jar, and the contents of the two jars mixed and stirred, the temperature being meanwhile noted. After standing an hour portions of this water containing the artificially fertilised ova were poured into glass jars containing 2 to 31/2 litres of sea-water. These jars were then transferred to a large glass tank, through which a stream of sea-water circulated, and were allowed to remain there throughout the whole period of development. Evaporation was prevented by covering the jars with glass lids. As a rule, the development was allowed to proceed for eight days, as the arms of the plutei attain their maximum development by the end of this time. A volume of saturated corrosive sublimate solution was then poured in each jar, such that the water should contain about '25 per cent, of it. In a few minutes all the larvae had sunk to the bottom. The supernatant liquid was poured off, and the larvae with 100 or 200 cub. centims. of water transferred to a small beaker, from which more of the liquid was poured off. The larvae were then washed in distilled water, and then in 50 percent, alcohol. They were finally transferred to, and preserved in, 70 percent, alcohol, to measure the larvae, they were washed on the slide in water, and mounted in glycerine. Several hundred, in positions suitable for measurement, could be obtained on a single slide. The larvae were measured under the microscope with a micrometer eyepiece, Zeiss, Obj. CC. Ocular, No. 3, The position of each larva measured was observed on the mechanical stage, and noted, so that it could not by mistake be measured twice. Three measurements were made, namely, the body length AB, the aboral arm length AC, and the oral arm length AD. The length of the calcareous skeleton in the body and limbs was always measured, in preference to the soft tissues surrounding it, as it is sharply defined, and therefore more suitable for the purpose. If is moreover of practically the same length as the soft tissues. In Fig. 1 are shown the measurements made. Only larvae in the position indicated in this figure were measured, as with larvae in the position indicated in Fig. 2, the oral arm is foreshortened.

scholarly journals Manifestation of the average mass of commercial tubers in interspecific hybrids of potatoes, their backсroses depending on the place and years of the test

2019 ◽  
pp. 22-29
Author(s):  
N.V. Kravchenko
Keyword(s):  
Coefficient Of Variation ◽  
Test Site ◽  
Meteorological Conditions ◽  
Average Weight ◽  
Research Station ◽  
Average Mass ◽  
External Conditions ◽  
The Difference ◽  
The Stability ◽  
Favorable Conditions

The successes in the selection of potato in the direction of creating varieties with a large average weight of commercial tubers depends on the quality of the source material, very desirable with the combination of high manifestation of the sign and the stability of its expression, regardless of external conditions. The researches were carried out in 2015–2017 under the conditions of the Ustymovskaya Research Station Plant (URSP) and the Sumy National Agrarian University (SNAU) in accordance with generally accepted methods in potato-growing. The starting material used different methods of creation, origin, degree of backing complex intraspecific hybrids with the participation of Mexican wild species. Significant potential of individual backcrosses has been revealed at the sign of a sign that is up to 1.8 times more than in the best grades. At the same time, he realized, depending on the external conditions is far from complete. Only in the most favorable for the meteorological complex in 2017, under the conditions of the SNAU, the proportion of hybrids having an average mass of one commercial tubers of more than 100 g was 75.8 %, and in the URSP it was 2,3 times less. The favorable conditions of the growing season of potato in 2017 are also evidenced by the proportion of hybrids with the maximum manifestation of the trait. In SNAU it was 28.3 %, and URSP – 25.3 %. The variability of the expression of the indicator at the test site is evidenced by the magnitude of its coefficient of variation. In the conditions of SNAU and URSP, the proportion of hybrids with a coefficient of variation of 10 % or less was 9.1 %. At the same time, in some hybrids the value of the indicator turned out to be very high – 50–70 %. Allocated hybrids, in which in each year the difference in the manifestation of the trait does not exceed 10–11 g, depending on the test site, namely: 90.673/30, 08.194/23 and 08.194/25, and in the hybrid 08.194/122 it was observed during 2015 and 2016 years. A different reaction of sister forms to the influence of the external complex was revealed. Among the hybrids 88.1450s2 and 88.1450s3 only in the latter under the conditions of the SNAU meteorological conditions almost did not affect the manifestation of signs – the coefficient of variation was 8%. With a difference of 1 g, the average mass of commercial tubers in this hybrid in the SNAU and URSP in 2015 was revealed. As a result of the study, it was possible to identify hybrids with a stable expression of the indicator irrespective of the meteorological conditions (08.194/25), for trials for three years in the SNAU (88.1450s3), URSP (08.194/33,08.194/119) and experimental locations (90.673/30,08.194/23 and 08.194/25). They are recommended for use in the breeding process with high adaptability.

scholarly journals One hundred years of atmospheric and marine observations at Utö Island, the Baltic Sea

2018 ◽  
Author(s):  
Lauri Laakso ◽  
Santtu Mikkonen ◽  
Achim Drebs ◽  
Anu Karjalainen ◽  
Pentti Pirinen ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Water Temperature ◽  
Sea Water ◽  
Seawater Temperature ◽  
Ice Cover ◽  
Atmospheric Temperature ◽  
Research Station ◽  
The Baltic Sea ◽  
Marine Research ◽  
The Baltic

Abstract. Utö Atmospheric and Marine Research Station is located on Utö Island (59°46’50 N, 21°22’23 E) at the outer edge of the Archipelago Sea, Baltic Sea towards the Baltic Sea Proper. Meteorological observations at the island started in 1881 and vertical profiling of sea water temperature and salinity in 1900. In this study, we analyze long-term changes of atmospheric temperature, cloudiness and sea salinity, temperature and ice cover. Our main dataset consists of 248 367 atmospheric temperature observations, 1632 quality assured vertical seawater temperature and salinity profiles and 8565 ice maps, partly digitized for this project. We also use North Atlantic Oscillation (NAO) and Major Baltic Inflow (MBI) data from the literature as reference variables to our data. Our analysis is based on statistical method utilizing dynamic linear model. The results show an increase in the atmospheric temperature at Utö, but the increase is significantly smaller than on land areas and takes place only since early 1980's, with a rate of 0.4 °C/decade during the last 35 years. We also see an increase on sea water temperatures, especially on the surface, with an increase of 0.3 °C/decade for the last 100 years. In deeper water layers the increase is smaller and influenced by vertical mixing, which is modulated by inflow of saline water from the North Sea and fresh water inflow. Date when air temperature in the spring exceeds +5 °C has become 5 days earlier from the period 1951–1980 to period 1981–2010 and date when sea surface water temperature exceed +4 °C has changed 9 days earlier. Sea ice cover duration at Utö shows a decrease of approximately 50 % during the last 35 years. Based on the combined results, it is possible that the climate at Utö may have changed into a new phase, in which ice do not reduce the local effects of global temperature increase.

scholarly journals The number of tubers in the bush in interspecific of the potatoes, their beckcrosses depending on the conditions of growth

2019 ◽  
Vol 2019 (1) ◽  
pp. 6-17
Author(s):  
N.V. Kravchenko ◽  
R. А. Bondus ◽  
V.G. Sklyar ◽  
A. A. Podhaietskiy ◽  
Z. B. Kienko ◽  
...  
Keyword(s):  
Key Words ◽  
Coefficient Of Variation ◽  
Interspecific Hybrids ◽  
Meteorological Conditions ◽  
Research Station ◽  
Standard Variety ◽  
External Conditions ◽  
The Difference

The experiments proved the value of many complex interspecific hybrids, their backcrosses according to the ability to tie more tubers in the nest than the best standard variety. Under the favorable external conditions, it was measured at more than 20 pieces/nest. In most hybrids, a significant impact on the implementation of the indicator of the places for the research (Sumy National Agrarian University and Ustymiv Research Station) and meteorological conditions of the years of the experiment (2015-2017). Based on the data on the distribution of hybrids by the quantity of the tubers in the nest, it has been found out that the best conditions for the manifestation of the signs were in SNAU in 2015 and 2016, and in the Ustymov research station in 2015. The biggest number of hybrids (6 pcs.) with the difference of 7 tubers/nest depending on the places of the experiment were found out in 2017 and the lowest number – in 2015. The opposite was true for the minimum difference in the manifestation of the indicator - 1 tuber/nest and less. Only single hybrids were characterized by a low value of the coefficient of variation of the manifestation of the sign (3-9%). The nursing forms reacted differently to the external conditions by the ability to tie tubers. Key words: tubers, interspecific hybrids, their backcrosses, number of tubers in the nest, meteorological conditions, places of the experiments, coefficient of the variation.

scholarly journals Space-time variability of alkalinity in the Mediterranean Sea

2014 ◽  
Vol 11 (9) ◽  
pp. 12871-12893 ◽  
Author(s):  
G. Cossarini ◽  
P. Lazzari ◽  
C. Solidoro
Keyword(s):  
Mediterranean Sea ◽  
Thermohaline Circulation ◽  
Sea Water ◽  
Dissolved Inorganic Carbon ◽  
Surface Flux ◽  
Atlantic Water ◽  
The Black Sea ◽  
Time Variability ◽  
Marginal Seas ◽  
The Mediterranean

Abstract. The paper provides a basin assessment of the spatial distribution of ocean alkalinity in the Mediterranean Sea. The assessment is made using a 3-D transport-biogeochemical-carbonate model to integrate the available experimental findings, which also constrains model output. The results indicate that the Mediterranean Sea shows alkalinity values that are much higher than those observed in the Atlantic Ocean on a basin-wide scale. A marked west-to-east surface gradient of alkalinity is reproduced as a response to the terrestrial discharges, the mixing effect with the Atlantic water entering from the Gibraltar Strait and the Black Sea water from Dardanelles, and the surface flux of evaporation minus precipitation. Dense water production in marginal seas (Adriatic and Aegean Seas), where alkaline inputs are relevant, and the Mediterranean thermohaline circulation sustains the west-to-east gradient along the entire water column. In the surface layers, alkalinity has a relevant seasonal cycle (up to 40 μmol kg−1) that is driven both by physical and biological processes. A comparison of alkalinity vs. salinity indicates that different regions present different relationships. In regions of freshwater influence, the two measures are negatively correlated due to riverine alkalinity input, whereas they are positively correlated in open seas. Alkalinity always is much higher than in the Atlantic waters, which might indicate a higher than usual buffering capacity towards ocean acidification, even at high concentrations of dissolved inorganic carbon.

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