Calculating the water and heat balances of the Eastern Mediterranean Basin using ocean modelling and available meteorological, hydrological and ocean data

AbstractEastern Mediterranean water and heat balances were analysed over 52years. The modelling uses a process-oriented approach resolving the one-dimensional equations of momentum, heat and salt conservation; turbulence is modelled using a two-equation model. The results indicate that calculated temperature and salinity follow the reanalysed data well. The water balance in the Eastern Mediterranean basin was controlled by the difference between inflows and outflows through the Sicily Channel and by net precipitation. The freshwater component displayed a negative trend over the study period, indicating increasing salinity in the basin. The heat balance was controlled by heat loss from the water surface, solar radiation into the sea and heat flow through the Sicily Channel. Both solar radiation and net heat loss displayed increasing trends, probably due to decreased total cloud cover. In addition, the heat balance indicated a net import of approximately 9Wm−2 of heat to the Eastern Mediterranean Basin from the Western Basin

Recentni trendovi oborine i budući scenariji nad Sredozemnim morem

This paper analyses current precipitation rates (PRs) and trends over the Mediterranean Sea region and their response to global climate change scenar- ios. The analysis uses 0.25° gridded PRs dataset over a 13-year period (1998–2010) based on remote sensing data from the Tropical Rainfall Measuring Mis- sion. Future scenarios use the results of six global climate models (GCMs) under four representative concentration pathway scenarios (i.e., RCP26, RCP45, RCP60, and RCP85). Results indicate that the Mediterranean Sea region displays a seasonally significant (insignificant) wetter trend during cold (hot) seasons, and exhibits annual spatial variation ranging from under 15 to over 100 mm month –1 over the period 1998–2010. Sea level pressure has two different effects on precipita- tion over the northern (inversely related to precipitation) versus southern (di- rectly related to precipitation) Mediterranean Sea. However, sea surface tem- perature is anti-correlated with precipitation. The GCMs that describe the current Mediterranean Sea precipitation most realistically are GFDL-CM3-1, MIROC-ESM-CHEM, and HadGEM2-AO, which are used to calculate the en- semble mean for each representative concentration pathway scenario. The en- semble means realizations indicate that the study area will experience substan- tial drought in the 21st century. Uncertainty in the projected precipitation over the Mediterranean Sea was partitioned into four sources, of which the used scenario dominates.U ovome radu analiziraju se aktualni intenziteti oborine (PR) i trendovi oborine nad područjem Sredozemnog mora i njihovi odzivi na scenarije općih klimatskih promjena. U analizi se koristi niz podataka intenziteta oborine u mreži od 0,25° tijekom 13-godišnjeg razdoblja (1998–2010) uzet iz podataka dobivenih daljinskim mjerenjima tijekom Misije mjerenja tropske oborine (Tropical Rainfall Measuring Mission, TRMM). Budući sce- nariji koriste rezultate iz šest općih klimatskih modela (globalni klimatski model, GCM) uz četiri scenarija reprezentativnih staza koncentracije (RCP) (tj. RCP26, RCP45, RCP60 i RCP85). Rezultati indiciraju da područje Sredozemnog mora pokazuje sezonski signifikantno (nesignifikantno) vlažniji trend tijekom hladnih (toplih) sezona, te tijekom promatranog razdoblja (1998–2010) prikazuje godišnju prostornu varijaciju koja se kreće u rasponu od 15 do preko 100 mm mjesec–1. Tlak zraka na razini mora ima dva različita učinka na oborinu nad Sredozemljem. Nad sjevernim Sredozemljem obrnuto je razmjeran oborini, dok je nad južnim Sredozemljem izravno razmjeran oborini. Međutim, temperatura površine mora je antikorelirana s oborinom. Opći klimatski modeli koji najrealističnije opisuju aktualnu oborinu nad Sredozemljem su: GFDL-CM3-1, MIROC-ESM-CHEM i HadGEM2-AO, a koriste se za izračun srednjaka ansambla za svaki scenarij reprezenta- tivne staze koncentracije. Realizacije srednjaka ansambla indiciraju da će područje studi- je doživjeti znatnu sušu u 21. stoljeću. Nesigurnost u projiciranoj oborini nad Sredozem- nim morem pripisana je četirima izvorima, gdje je od njih najvažniji korišteni scenarij

Recentni trendovi oborine i budući scenariji nad Sredozemnim morem

This paper analyses current precipitation rates (PRs) and trends over the Mediterranean Sea region and their response to global climate change scenar- ios. The analysis uses 0.25° gridded PRs dataset over a 13-year period (1998–2010) based on remote sensing data from the Tropical Rainfall Measuring Mis- sion. Future scenarios use the results of six global climate models (GCMs) under four representative concentration pathway scenarios (i.e., RCP26, RCP45, RCP60, and RCP85). Results indicate that the Mediterranean Sea region displays a seasonally significant (insignificant) wetter trend during cold (hot) seasons, and exhibits annual spatial variation ranging from under 15 to over 100 mm month –1 over the period 1998–2010. Sea level pressure has two different effects on precipita- tion over the northern (inversely related to precipitation) versus southern (di- rectly related to precipitation) Mediterranean Sea. However, sea surface tem- perature is anti-correlated with precipitation. The GCMs that describe the current Mediterranean Sea precipitation most realistically are GFDL-CM3-1, MIROC-ESM-CHEM, and HadGEM2-AO, which are used to calculate the en- semble mean for each representative concentration pathway scenario. The en- semble means realizations indicate that the study area will experience substan- tial drought in the 21st century. Uncertainty in the projected precipitation over the Mediterranean Sea was partitioned into four sources, of which the used scenario dominates.U ovome radu analiziraju se aktualni intenziteti oborine (PR) i trendovi oborine nad područjem Sredozemnog mora i njihovi odzivi na scenarije općih klimatskih promjena. U analizi se koristi niz podataka intenziteta oborine u mreži od 0,25° tijekom 13-godišnjeg razdoblja (1998–2010) uzet iz podataka dobivenih daljinskim mjerenjima tijekom Misije mjerenja tropske oborine (Tropical Rainfall Measuring Mission, TRMM). Budući sce- nariji koriste rezultate iz šest općih klimatskih modela (globalni klimatski model, GCM) uz četiri scenarija reprezentativnih staza koncentracije (RCP) (tj. RCP26, RCP45, RCP60 i RCP85). Rezultati indiciraju da područje Sredozemnog mora pokazuje sezonski signifikantno (nesignifikantno) vlažniji trend tijekom hladnih (toplih) sezona, te tijekom promatranog razdoblja (1998–2010) prikazuje godišnju prostornu varijaciju koja se kreće u rasponu od 15 do preko 100 mm mjesec–1. Tlak zraka na razini mora ima dva različita učinka na oborinu nad Sredozemljem. Nad sjevernim Sredozemljem obrnuto je razmjeran oborini, dok je nad južnim Sredozemljem izravno razmjeran oborini. Međutim, temperatura površine mora je antikorelirana s oborinom. Opći klimatski modeli koji najrealističnije opisuju aktualnu oborinu nad Sredozemljem su: GFDL-CM3-1, MIROC-ESM-CHEM i HadGEM2-AO, a koriste se za izračun srednjaka ansambla za svaki scenarij reprezenta- tivne staze koncentracije. Realizacije srednjaka ansambla indiciraju da će područje studi- je doživjeti znatnu sušu u 21. stoljeću. Nesigurnost u projiciranoj oborini nad Sredozem- nim morem pripisana je četirima izvorima, gdje je od njih najvažniji korišteni scenarij

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

Net precipitation over the Baltic Sea for one year using several methods

Precipitation and evaporation over the Baltic Sea are calculated for a one-year period from September 1998 to August 1999 by four different tools, the two atmospheric regional models HIRLAM and REMO, the oceanographic model PROBE-Baltic in combination with the SMHI (1 × 1)° database and Interpolated Fields, based essentially on ship measurements. The investigated period is slightly warmer and wetter than the climatological mean. Correlation coefficients of the differently calculated latent heat fluxes vary between 0.81 (HIRLAM and REMO) and 0.56 (SMHI/PROBE-Baltic and Interpolated Fields), while the correlation coefficients between model fluxes and measured fluxes range from 0.61 and 0.78. Deviations of simulated and interpolated monthly precipitation over the Baltic Sea are less than ±5 mm in the southern Baltic and up to 20 mm near the Finnish coast for the one-year period. The methods simulate the annual cycle of precipitation and evaporation of the Baltic Proper in a similar manner with a broad maximum of net precipitation in spring and early summer and a minimum in late summer. The annual averages of net precipitation of the Baltic Proper range from 57 mm (REMO) to 262 mm (HIRLAM) and for the Baltic Sea from 96 mm (SMHI/PROBE-Baltic) to 209 mm (HIRLAM). This range is considered to give the uncertainty of present-day determination of the net precipitation over the Baltic Sea

Human impacts and their interactions in the Baltic Sea region

Coastal environments, in particular heavily populated semi-enclosed marginal seas and coasts like the Baltic Sea region, are strongly affected by human activities. A multitude of human impacts, including climate change, affect the different compartments of the environment, and these effects interact with each other. As part of the Baltic Earth Assessment Reports (BEAR), we present an inventory and discussion of different human-induced factors and processes affecting the environment of the Baltic Sea region, and their interrelations. Some are naturally occurring and modified by human activities (i.e. climate change, coastal processes, hypoxia, acidification, submarine groundwater discharges, marine ecosystems, non-indigenous species, land use and land cover), some are completely human-induced (i.e. agriculture, aquaculture, fisheries, river regulations, offshore wind farms, shipping, chemical contamination, dumped warfare agents, marine litter and microplastics, tourism, and coastal management), and they are all interrelated to different degrees. We present a general description and analysis of the state of knowledge on these interrelations. Our main insight is that climate change has an overarching, integrating impact on all of the other factors and can be interpreted as a background effect, which has different implications for the other factors. Impacts on the environment and the human sphere can be roughly allocated to anthropogenic drivers such as food production, energy production, transport, industry and economy. The findings from this inventory of available information and analysis of the different factors and their interactions in the Baltic Sea region can largely be transferred to other comparable marginal and coastal seas in the world