Estimating Currents From Argo Trajectories in the Bothnian Sea, Baltic Sea

Argo floats have been used in the environmental monitoring of the very shallow Bothnian Sea, a sub-basin of the Baltic Sea, for 5 years as part of the Finnish Euro-Argo programme. The Bothnian Sea is so far considered to be an environmentally healthy part of the Baltic Sea because the deep waters of the basin are well-ventilated by inflowing oxygen-rich saltier and heavier surface layer waters of the Baltic Sea proper. Thus the deep water flow is of interest in the Bothnian Sea. In this study, we used Argo float data from six different long-term missions, from 111 to 512 days, to analyze the deep-water flow in the Bothnian Sea where no continuous monitoring of currents exist. We estimated mainly the flow below the expected halocline from the paths of the floats. We analyzed the movements statistically and estimated the error caused by the surface drift of the floats during their stay at the surface by using 3D hydrodynamic model results as reference data. Our results show a northward flowing resultant current in the deep trench of the Bothnian Sea. There seemed to be very little exchange between coastal zone and open-sea waters in deeper layers. The drifting speed of the floats in the deep layers of Bothnian Sea generally was around 2 cm/s but instantaneous speeds of up to 30 cm/s in the middle-layer (50 dbars) were observed. In the Bothnian Sea deep, the deep trench on the Finnish side of the Bothnian Sea, the vast majority of the observations showed deep currents from south to north, with the same average speed of around 2 cm/s but the instantaneous maximum was smaller at 13 cm/s. Our study indicates that the routine Argo float observations can be used to get information on the deep currents in the basin in addition to hydrographic observations.Peer reviewe

Report on the evaluation of the RBRargo|2000 OEM sensor from at sea data analysis

Report of evaluation of the RBRargo|2000 OEM sensor based on at sea experiments on Baltic Sea and North Atlantic, and other national experiment

A report on the adaptation of existing DMQC methods to marginal seas

A report on the adaptation of existing DMQC methods to marginal seas (Arctic, Baltic and Mediterranean Seas)

Ilmastonmuutokseen sopeutumisen ohjauskeinot, kustannukset ja alueelliset ulottuvuudet

202

Simulaatiot jauheen käyttäytymisen ymmärtämisen apuna

The aim of this study was to investigate powder and tablet behavior at the level of mechanical interactions between single particles. Various aspects of powder packing, mixing, compression, and bond formation were examined with the aid of computer simulations. The packing and mixing simulations were based on spring forces interacting between particles. Packing and breakage simulations included systems in which permanent bonds were formed and broken between particles, based on their interaction strengths. During the process, a new simulation environment based on Newtonian mechanics and elementary interactions between the particles was created, and a new method for evaluating mixing was developed. Powder behavior is a complicated process, and many of its aspects are still unclear. Powders as a whole exhibit some aspects of solids and others of liquids. Therefore, their physics is far from clear. However, using relatively simple models based on particle-particle interaction, many powder properties could be replicated during this work. Simulated packing densities were similar to values reported in the literature. The method developed for describing powder mixing correlated well with previous methods. The new method can be applied to determine mixing in completely homogeneous materials, without dividing them into different components. As such, it can describe the efficiency of the mixing method, regardless of the powder's initial setup. The mixing efficiency at different vibrations was examined, and we found that certain combinations of amplitude, direction, and frequencies resulted in better mixing while using less energy. Simulations using exponential force potentials between particles were able to explain the elementary compression behavior of tablets, and create force distributions that were similar to the pressure distributions reported in the literature. Tablet-breaking simulations resulted in breaking strengths that were similar to measured tablet breaking strengths. In general, many aspects of powder behavior can be explained with mechanical interactions at the particle level, and single particle properties can be reliably linked to powder behavior with accurate simulations.Jauhe on aineen olomuotona erikoisessa asemassa. Vaikka se on selkeästi kiinteää, sitä voidaan kaataa ja sekoittaa osin samaan tapaan kuin nesteitä. Jauheen käyttäytyminen erilaisissa tilanteissa on edelleen epäselvää. Jauheen ominaisuuksia, kuten pakkautuvuutta tai valuvuutta, voidaan käsitellä sellaisenaan. Kuitenkin nämä jauheen yleiset ominaisuudet johtuvat sen yksittäisten partikkelien välisistä vuorovaikutuksista ja ominaisuuksista. Partikkelien välisiä tapahtumia on kuitenkin vaikeaa havaita suoraan kokeissa. Simuloitaessa sama tilanne, sen vuorovaikutuksia päästään tutkimaan tarkemmin. Tämän työn tavoitteena oli tutkia jauhemaisen aineen fysikaalista käyttäytymistä tietokonesimulaatioiden avulla, lähtien yksinkertaisista, partikkelien välisistä vuorovaikutuksista. Työn aikana rakennettiin tietokoneohjelmisto jolla voitiin mallintaa jauheen pakkautumista, sekoittumista, segregaatiota, sekä jauhe-materiaalin puristamista tableteiksi ja näin syntyneiden tablettien murtumista. Partikkelien ominaisuuksia muuteltiin simulaatiosta toiseen, jotta saatiin arvioitua näiden vaikutusta kulloinkin tarkasteltavaan ilmiöön. Muuteltuja ominaisuuksia olivat mm. partikkelien väliset kitkakertoimet, kimmokerroin ja pehmeys. Jauheiden sekoitusta tutkittaessa muuteltiin myös sekoitukseen käytetyn heilahtelun nopeutta, suuntaa ja suuruutta, jotta näiden vaikutusta sekoituksen eri osa-alueisiin voitiin tutkia. Sekoitustutkimusten yhteydessä kehitettiin uusi menetelmä arvioida sekoitustapahtuman laatua. Menetelmän periaatteena on seurata partikkelien sijaintien muutoksia suhteessa toisiinsa. Tällöin jauheen alkuperäinen sekoittumisen aste ei vaikuta sekoitustapahtuman arviointiin. Simulaatiokokeissa saadut tulokset jauheen pakkautumisesta ja sekoittumisesta vastasivat hyvin kirjallisuuden tuloksia. Uusi sekoittumisen arviontitapa vastasi hyvin ennen käytettyjä menetelmiä. Simulaatiomallissa puristettujen tablettien voimajakaumat vastasivat kirjallisuudesta saatuja tiheysjakaumia. Simuloiden murrettujen tablettien kesto vastasi laboratoriossa murrettuja tabletteja. Yleisesti ottaen voidaan todeta, että monet jauheen käyttäytymisen ilmiöt voitiin toisintaa tietokonemalleilla käyttäen verrattain yksinkertaisia fysikaalisia malleja

D4.12 Report on operational deployments of the two prototypes with N03 and Irradiance

<p>Report on the prototype deployments on Baltic Sea and recommendations based on current experiences.</p&gt