Handbook of best practices

1. Observatories
1.1 Introduction
The “Best Practices” handbook aims to establish optimal ways for users desirous to
implement fixed stations in open ocean region. This report is based on FixO3 community
experiences and recommendations from previous European projects (ESONET, JERICO). It
describes all procedures used within the network, such as maintenance, service, sensors
calibration, pre and post deployment operations as well as data transfer and data
qualification necessary to operate an open sea observatory.
The FixO3 “Best Practices” handbook will be the backbone for the next FixO3 label which
aims to set up a list of rules and recommendations for open ocean fixed observatories
(standalone and cabled).
1.2 Platform types (CNR, IFREMER, INGV, IEO)
The FixO3 network includes fixed open ocean platforms able to collect in-situ measurements
from the upper atmosphere down to the ocean interior and the sea bottom.
Several types of systems can address these issues and the choice about the most suitable
platform is related to the physical processes to be investigated, to the environmental
constraints of the deployment area and to the expected monitoring period (in the medium or
long term).
The following sections present different types of Eulerian systems that can be used in a
single site or combined together in arrays to enhance the monitoring capabilities of any
desired observatory exploiting the advantages of each system.
1.2.1 Mooring lines
Moorings are a series of pieces of in line rope equipped with autonomous oceanographic
and biogeochemical sensors. Moorings are anchored on sea-floor and can be used in
coastal or off-shore waters, in shallow, intermediate or even deep waters.
The main components of a mooring are:
• anchor, generally constituted of railroad car wheels or a block of heavy material (i.e.,
iron, concrete, etc.) to be used as ballast. It plays a very important role in the design
of the overall mooring since it must be dimensioned to guarantee that the mooring
line remains in position counterbalancing the buoyancy but should not too heavy as
this would put considerable tension on the wire during the deployment which may
even cause the wire to break. The anchor is often lost/remains as at the seafloor after
recovery, at least in high seas. Within 200 mile zones some countries request
anchors to be recovered (e.g. Norway). This practice should be the rule once
observatories become permanent.
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