illustrates the clear situation after the EVRS based 
harmonized vertical reference system has been 
taken into use. 
It is vital for the mariner that charted depths and 
broadcasted water level information are in the same 
reference system. To provide all the information 
safely and reliably to the users during the transition 
period, it is essential to have a good cooperation 
and communication between different organisations 
like national hydrographic offices, geodetic and 
oceanographic organizations (e.g. BOOS) and 
mariners and other users of water level data both in 
national and international level. 
CDWG will now concentrate on guiding the 
implementation process of the harmonized vertical 
reference system by preparing a road map and 
monitoring the status of the implementation 
process. CDWG supports efficient international 
communication and cooperation with relevant 
bodies. In addition CDWG will study other water 
level related issues, e.g. possibilities to develop 
common geoid model for the Baltic Sea and foster 
studies related to dynamic topography of sea surface 
in the Baltic Sea. 
The implementation process will take several 
years: the transition is estimated to be completed 
by 2020. To make the transition process successful 
one of the key issues is to get all relevant national 
and international bodies to communicate and 
cooperate together. CDWG is one node point for 
this important international network. 
Jyrki Mononen is working at the Finnish Transport Agency. 
Since 2013 he has been acting as the chairman of the BSHC 
CDWG. 
Dr U iltneil Ellmer is working at the Federal Maritime and 
Hydrographic Agency in Rostock, Germany. He is the German 
representative in the BSHC CDWG. 
Thomas Hammarklint is working at the Swedish Meteorological 
and Hydrological Institute (SMHI). Since 2003 he has been 
working with exchange of water level data in the Baltic Sea and 
is the BOOS representative in the BSHC CDWG. 
Lars Jakobsson is working at the Swedish Maritime Administra 
tion. He is the Swedish representative in the BSHC CDWG. 
E-mail: jyrM.mononenfb.liikennevirasto.fi. 
INSTITUTIONAL 
RESEARCH TOPIC AT 
THE MARINE SYSTEMS 
INSTITUTE FOR 
2014-2019 
Urmas Lips 
halocline) of the Baltic Sea. The in-situ observations 
using novel technologies combined with remote 
sensing and high-resolution numerical simulations 
are the main study method that allows tracking 
of physical and biogeochemical signal dynamics 
at a wide range of temporal and spatial scales. 
We aim to make a substantial step forward in the 
quantitative description of submesoscale processes 
and their impact on the biogeochemical cycles in 
the stratified Baltic Sea. 
Background 
A six-year proj ect aiming at enhancing predictability 
of the Baltic Sea system was initiated by the research 
team of the Marine Systems Institute at Tallinn 
University of Technology in 2014 (supported by the 
Estonian Ministry of Education and Research). The 
project is focused on multi-scale physical processes 
that significantly control the biogeochemical cycles 
of substances as well as mixing and dispersion of 
particles and pollutants, especially in the boundary 
layers (near-surface and near-bottom layer) and 
in the pycnoclines (seasonal thermocline and 
Methods of in-situ observations 
While the study is based on the combined use of the 
data from in-situ and remote sensing observations 
and numerical simulations, here the approaches 
of in-situ observations focused on processes in 
the upper and subsurface (thermocline) layers are 
presented. The core of the measurement complex