2005년 대한 생화학·분자생물학회 하계학술대회를 다녀와서

Circulation in the Western Mediterranean Sea

We review what is known about the convective process in the open ocean, in which the properties of large volumes of water are changed by intermittent, deep-reaching convection, triggered by winter storms. Observational, laboratory, and modeling studies reveal a fascinating and complex interplay of convective and geostrophic scales, the large-scale circulation of the ocean, and the prevailing meteorology. Two aspects make ocean convection interesting from a theoretical point of view. First, the timescales of the convective process in the ocean are sufficiently long that it may be modified by the Earth's rotation; second, the convective process is localized in space so that vertical buoyancy transfer by upright convection can give way to slantwise transfer by baroclinic instability. Moreover, the convective and geostrophic scales are not very disparate from one another. Detailed observations of the process in the Labrador, Greenland, and Mediterranean Seas are described, which were made possible by new observing technology. When interpreted in terms of underlying dynamics and theory and the context provided by laboratory and numerical experiments of rotating convection, great progress in our description and understanding of the processes at work is being made.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/98RG02739

Open-ocean convection: Observations, theory, and models

Heatwaves are important climatic extremes in atmospheric and oceanic systems that can have devastating and long-term impacts on ecosystems, with subsequent socioeconomic consequences. Recent prominent marine heatwaves have attracted considerable scientific and public interest. Despite this, a comprehensive assessment of how these ocean temperature extremes have been changing globally is missing. Using a range of ocean temperature data including global records of daily satellite observations, daily in situ measurements and gridded monthly in situ-based data sets, we identify significant increases in marine heatwaves over the past century. We find that from 1925 to 2016, global average marine heatwave frequency and duration increased by 34% and 17%, respectively, resulting in a 54% increase in annual marine heatwave days globally. Importantly, these trends can largely be explained by increases in mean ocean temperatures, suggesting that we can expect further increases in marine heatwave days under continued global warming.

/pdf/longer-and-more-frequent-marine-heatwaves-over-the-past-2qkkojl57f.pdf

Longer and more frequent marine heatwaves over the past century

Little doubt is left that climate change is underway, strongly affecting the Earth's biodiversity. Some of the greatest challenges ahead concern the marine realm, but it is unclear to what extent changes will affect marine ecosystems. The Mediterranean Sea could give us some of the answers. Data recovered from its shores and depths have shown that sea temperatures are steadily increasing, extreme climatic events and related disease outbreaks are becoming more frequent, faunas are shifting, and invasive species are spreading. This miniature ocean can serve as a giant mesocosm of the world's oceans, with various sources of disturbances interacting synergistically and therefore providing an insight into a major unknown: how resilient are marine ecosystems, and how will their current functioning be modified?

https://www.cell.com/trends/ecology-evolution/pdf/S0169-5347(09)00338-3.pdf

Climate change effects on a miniature ocean: the highly diverse, highly impacted Mediterranean Sea

Heavy metals such as lead, mercury, cadmium, zinc and copper are among the most important pollutants because of their non-biodegradability and toxicity above certain thresholds. Here, we review methods for sensing heavy metal ions (HMI) in water samples using screen-printed electrodes (SPEs) as transducers. The review (with 107 refs.) starts with an introduction into the topic, and this is followed by sections on (a) mercury-coated SPEs, (b) bismuth-coated SPEs, (c) gold-coated SPEs (d) chemically modified and non-modified carbon SPEs, (e) enzyme inhibition-based SPEs, and (f) an overview of commercially available electrochemical portable heavy metal analyzers. The review reveals the significance of SPEs in terms of decentralized and of in situ analysis of heavy metal ions in environmental monitoring.

Screen-printed electrodes for environmental monitoring of heavy metal ions: a review

[1] The deep waters of the western Mediterranean are known to have an almost constant trend towards higher salinity and temperature values since the 1950s. Recent observations have shown an acceleration of this tendency, which has been attributed by some authors to the effect of the propagation of the signal of the Eastern Mediterranean Transient, from east to west. From 2004 to 2006 five basin-scale oceanographic cruises evidenced a relevant change in the deep structure of the western Mediterranean. In less than two years almost the whole deep basin has been filled with highly saline and warm new deep water, which substantially renewed the resident deep water. The paper shows evidence of the rapid basin-wide extension of the event, giving insights into the origin and the propagation of the new deep water towards the basin interior and showing the evolution of the deep characteristics.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2008GL035146

An extensive western Mediterranean deep water renewal between 2004 and 2006

. The effects of the 2003 European heatwave on the sea surface layer of the Central Mediterranean were studied using a regional 3-D ocean model. The model was used to simulate the period 2000 to 2004 and its performance was validated using remotely-sensed and in situ data. Analysis of the results focused on changes in the Sea Surface Temperature (SST) and on changes to the surface and sub-surface current field. This permitted us to identify and quantify the anomalies of atmospheric and sea surface parameters that accompanied the heatwave. The dominant annual cycle in each variable was first removed and a wavelet analysis then used to locate anomalies in the time-frequency domain. We found that the excess heating affecting the sea surface in the summer of 2003 was related to a significant increase in air temperature, a decrease in wind stress and reduction of all components of the upward heat flux. The monthly averages of the model SST were found to be in good agreement with remotely-sensed data during the period studied, although the ocean model tended to underestimate extreme events. The spatial distribution of SST anomalies as well as their time-frequency location was similar for both the remotely-sensed and model temperatures. We also found, on the basis of the period of the observed anomaly, that the event was not limited to the few summer months of 2003 but was part of a longer phenomenon. Both the model results and experimental data suggest the anomalous heating mainly affected the top 15 m of ocean and was associated with strong surface stratification and low mixing. The skill of the model to reproduce the sub-surface hydrographic features during the heatwave was checked by comparison with temperature and salinity measurements. This showed that the model was generally in good agreement with observations. The model and observations showed that the anomalous warming also modified the currents in the region, most noticeably the Atlantic Ionian Stream (AIS) and the Atlantic Tunisian Current (ATC). The AIS was reduced in intensity and showed less meandering, mainly due to the reduced density gradient and low winds, while the ATC was enhanced in strength, the two currents appearing to modulate each other in order to conserve the total transport of Modified Atlantic Water.

/pdf/effects-of-the-2003-european-heatwave-on-the-central-22mjguvbjg.pdf

Effects of the 2003 European heatwave on the Central Mediterranean Sea: surface fluxes and the dynamical response

Oil spill hazard and risk assessment for the shorelines of a Mediterranean coastal archipelago

. A high resolution eddy-resolving primitive equation numerical model, based on the Princeton Ocean Model (POM), is used to study the seasonal variability of the general circulation in the Central Mediterranean Sea. The model is run on a seasonal cycle, perpetual year simulation for five years, with nesting to the coarser resolution Ocean General Circulation Model (OGCM), covering the whole Mediterranean Sea. The model results are compared to the current knowledge on the hydrography and dynamics of the area, with a special focus on the annual cycle of the Modified Atlantic Water (MAW), on the circulation in the Sardinia Channel, the water exchange across the Strait of Sicily, and on the transition and fate of the Levantine Intermediate Water (LIW). The results show that the adopted coupling techniques between the two models give a proficient downscaling of the large-scale OGCM flow field into the regional scale model. The numerical solution is also used to highlight the seasonal characteristics of important dynamical features in the area, as well as to shed light on the scarcely known circulation regimes along the north African shelf and slope. Key words. Oceanography: general (numerical modelling); Oceanography: physical (currents; general circulation)

/pdf/seasonal-variability-in-the-central-mediterranean-sea-2a45xfa8dv.pdf

Alberto Ribotti

Papers

Screen-printed electrodes for environmental monitoring of heavy metal ions: a review

An extensive western Mediterranean deep water renewal between 2004 and 2006

Effects of the 2003 European heatwave on the Central Mediterranean Sea: surface fluxes and the dynamical response

Oil spill hazard and risk assessment for the shorelines of a Mediterranean coastal archipelago

Seasonal variability in the Central Mediterranean Sea circulation