Download the wmo voluntary observing ship programme

World
Meteorological
Organization
THE WMO
VOLUNTARY
OBSERVING
SHIP PROGRAMME:
Intergovernmental
Oceanographic
Commission
of UNESCO
AN ENDURING PARTNERSHIP
W
eather forecasting, operational
planning for maritime activities, the design of
vessels and coastal and offshore facilities, the
exploitation of marine and sea-bed resources,
the response to oil spills at sea and climate
research all require a knowledge of weather
conditions over the oceans. This pamphlet
highlights the continuing importance of
meteorological observations from voluntary
observing ships (VOS) in addressing these
information requirements and in illustrating
the vital nature of the data provided by this
highly cost-effective mechanism.
Mariners face many hazards — storms,
rough seas, ice and icebergs. As early as 1853,
this reality led seafaring nations to organize
the first formal international meteorological
meeting to coordinate weather observing at
sea. Since that time, ships’ meteorological
observations have provided essential inputs
to weather warnings and forecasts, which
have become progressively more accurate.
During the past two decades, however, the
need for improved knowledge of ocean
weather and climate has been further
reinforced by the threat of global warming
and by the prospect that weather forecasts
can be made on time-scales of months to
years by using information on oceanic
conditions. In response to these expanded
requirements, the World Meteorological
Organization (WMO) and the
Intergovernmental Oceanographic
Commission (IOC) of the United Nations
Educational, Scientific and Cultural
Organization (UNESCO) have been working
with the maritime community to enhance
voluntary observational programmes carried
out by ships at sea.
Today, WMO’s World Weather Watch
(WWW) coordinates round-the-clock monitoring to take the pulse of the weather over
Temperature and humidity profiles over the oceans are vital to
weather and climate forecasting.
At the global level, the WMO World
Weather Watch Programme is the
international cooperative programme which
arranges for the gathering and
distribution, in real time and on a
worldwide scale, of meteorological
information including marine weather and
oceanographic observations, forecasts and
other bulletins.
the oceans and the continents, drawing on
meteorological observations from ships,
drifting and moored buoys, oil rigs and
orbiting satellites as well as from inland
observing sites. The WMO VOS Programme,
under which ships are recruited by National
Meteorological Services (NMSs) to record
and transmit meteorological observations
(the most critical being air pressure, air
temperature, sea-surface temperature, wind
and sea state), is a vital component of the
WWW. Meteorological observations made
Observations from Voluntary Observing Ships are a vital
component of the World Weather Watch
Severe weather conditions
will always pose a hazard to
ships and cargoes.
by officers onboard vessels participating in
the programme are recorded in
meteorological logbooks and coded in a
standardized format for immediate
transmission to shore. They are then routed
around the world on WMO’s Global
Telecommunication System (GTS) for use
by meteorologists, ship routing services,
radio and television broadcasts and other
clients. Until recently, VOS reports were
usually transmitted in Morse code to
coastal radio stations but, with the
implementation of the Global Maritime
Distress and Safety System (GMDSS), most
are now relayed via satellite
communication or by voice radio.
Vessels participating in the VOS
Programme are generally classified into one
of three major categories. So-called “Selected
Ships” carry out a complete programme of
meteorological observations and utilize the
full WMO SHIP code for relay of their reports;
“Supplementary Ships” undertake a
somewhat reduced observational programme
and use an abbreviated code form; and any
vessel travelling through a data-sparse region
may be recruited into a third category, known
as “Auxiliary Ships”, and requested to supply
limited observations. Worldwide VOS
numbers reached a peak of about 7 700 ships
in 1984–85 but have declined since that time
with just over 6 700 vessels from 52 countries
participating in early 2000. This decline
reflects the continuing trend towards fewer
but larger ships but has been balanced, to
some extent, by the fact that vessels, in
general, now spend reduced time in port.
This fact, in addition to improved
communications via satellite, has actually
lead to enhancements in both the quantity
and the quality of meteorological reports
received from the VOS.
The VOS Programme operates at no direct
cost to participating vessels. No
communication charges are levied for the
transmission of meteorological observations
from these vessels. In addition, Port
Meteorological Officers (PMOs) provide free
training both in weather observing and in the
use of WMO codes, while essential
meteorological supplies are also provided by
participating NMSs.
Damage from sea
ice and icebergs is
also an ongoing
threat to shipping
in high latitudes.
ARE OBSERVATIONS FROM VOLUNTARY
OBSERVING SHIPS REALLY NECESSARY TODAY?
The question “Do we really need observations
from ships now that we have weather
satellites?” is still frequently asked, even
though the need for enhanced observational
coverage of the world’s oceans is increasingly
accepted. The answer is most emphatically
“YES”!
Observations from VOS significantly
complement the bird’s eye view of the global
distribution of clouds, weather systems and
ocean variables obtained from satellites, as
well as provide a long-term observational
record. They supply information on variables
and phenomena which cannot, as yet, be
accurately, reliably and consistently observed
from space. Perhaps the most critical of these
variables is surface air pressure. Along with
measurements from buoys and other surface
platforms, they are essential for the
More VOS are needed in the southern oceans and high
latitude waters.
Mapping position plot chart of data received during
August 2000
Messages:SHIP
Total:
181 329
calibration or “ground-truthing” of satellite
observations. Furthermore, reports from VOS
continue to be used routinely in the
preparation of weather forecasts, thus
supplying a constant “reality check” on actual
weather conditions, contributing directly to
short-range prediction and providing
important inputs to numerical weather
prediction (NWP) models1. Both observations
from VOS and satellite data are, today,
indispensable and complementary
meteorological tools. Without VOS
observations, the provision of timely and
accurate weather forecasts and warnings for
mariners would be seriously compromised.
It is less widely appreciated that historical
records of observations from VOS also find
ever-increasing practical applications, in this
way contributing design statistics used in
1 Modern weather forecasting relies heavily on
computerized NWP models. The accuracy of NWP
model forecasts, however, depends on the accuracy of
the initial conditions used to start the model runs. VOS
observations are vitally important in establishing
accurate initial conditions over the vast oceanic areas
of the globe.
ship and oil rig construction and in coastal
engineering, facilitating the selection of
seasonal “weather windows” for vulnerable
marine operations and underpinning the
analysis of climatic variations. Reflecting the
importance of these historical records of
oceanic weather conditions, WMO
established the Marine Climatological
Summaries Scheme in 1963. Under this
scheme, observations recorded in ships’
meteorological logbooks are extracted,
quality controlled, archived, processed into
climatological summaries and exchanged in a
globally coordinated and consistent manner.
In addition, historical marine meteorological
observations recorded in ships’ logbooks
since the nineteenth century form one of the
longest continuous climate records in
existence and are essential to the assessment
of natural and anthropological climate
changes. It is vital that this record be
continued.
In summary, the observations from VOS
continue to provide essential inputs to
operational weather forecasting, supply
“ground truth” measurements for calibration
of satellite readings, add to our growing
knowledge of ocean climates, increase our
understanding of the linkages between the
oceans and the atmosphere and contribute to
the development of important historical
databases. The advent of the age of the
weather satellite has in no way diminished
the importance of reports from VOS.
THE EXPANDING REQUIREMENTS
FOR OCEAN OBSERVATIONS
During the past several decades, three major
factors have combined to increase the need
for observations from the world’s oceans:
(a) The growth in the demand for specialized
marine meteorological services;
(b) El Niño/Southern Oscillation (ENSO) and
the potential for useful long-range
forecasts; and
(c) The spectre of global warming.
VOS meteorological instrumentation is maintained and
calibrated by port meteorological officers.
Specialized marine
meteorological services
Since the end of the Second World War,
marine meteorology has expanded to include
a variety of specialized or tailored services.
Weather routing has become a highly valued
service for vessels engaged in trans-ocean
voyages. The commercial fishing industry has
become increasingly reliant on up-to-date
meteorological and oceanographic
observations and forecasts to optimize fishing
Observations from the oceans are essential to understanding the
Earth’s climate system
Automated
shipboard
observational
and data
transmission
systems are
under
development in
several
countries.
effort. Tailored products support increased
traffic volumes and ship sizes in coastal
regions and harbours as well as the
operations of specialized vessels such as
hovercraft, hydrofoils and high-speed ferries.
Site-specific meteorological support has
become critically important to sensitive
offshore oil and gas operations such as
drilling, pipe laying and re-supply as well as
to respond to oil spills at sea. All of these
services have generated pressures for more
detailed and accurate observational data from
the open sea, coastal waters and harbour
approaches.
Remember:
help improve the quality of
forecasts and warnings and
contribute to the
enhancement of safety at sea.
Become involved with
the VOS!
The promise of accurate
long-range forecasts
Climate is subject to variations on all timescales, from seasons to decades and beyond.
The best known of these variations is
associated with the ENSO phenomenon. This
shift or seesaw of atmospheric pressure
across the equatorial Pacific Ocean occurs
irregularly, roughly every two to seven years
and is linked to changes in tropical seasurface temperature patterns, with the
eastern Pacific tending to be unusually warm
during El Niño years. Around the globe,
droughts, floods, the collapse of important
fisheries and other unusual phenomena are
often associated with El Niño. The existence
of a connection between tropical sea-surface
temperatures and weather in distant regions
for months ahead has raised hopes that
useful monthly to seasonal weather forecasts
can be developed. This has stimulated efforts
to develop such products, bringing increased
requirements for observations from ocean
areas.
(continue in other side)
For more information about the VOS,
please contact:
Ocean Affairs Division
World Meteorological Organization
7 bis, avenue de la Paix
P.O. Box 2300
CH-1211 Geneva 2, SWITZERLAND
✆:
(41 22) 730 82 37
Fax:
(41 22) 730 80 21
E-mail: [email protected]
Internet: http://www.wmo.ch
Unusual weather
conditions are often
experienced around the
globe during the El Niño
years.
The spectre
of global warming
During the past two decades, concern
regarding the potential impacts of global
warming has intensified efforts to understand
the functioning of the global climate system.
In addressing this challenge, the Second
World Climate Conference (Geneva, 1990)
identified the need for a comprehensive
ocean observing system as a vital component
of the Global Climate Observing System
(GCOS). Subsequently, in 1998, the
Conference of the Parties to the United
Nations Framework Convention on Climate
Change (UNFCCC) called on the world’s
Governments to enhance substantially
Both the ocean and atmosphere are
regularly measured from the VOS.
There is a need for a long-term observing
system to monitor, describe and understand
the physical and biogeochemical processes
that determine the ocean circulation, the
seasonal-to-century climate changes in the
ocean, and to provide observations needed
for climate predictions......... Most ocean
measurements are not made on adequate
temporal and spatial scales. ……….. Data
coverage is very poor, particularly in
southern latitudes, in Polar regions, and in
the deep ocean.
systematic monitoring and data collection
activities over and within the oceans.
The provision of specialized services, the
development of long-range forecasts and
climate change research require oceanic
observations with increased accuracy and
coverage. In 1988, WMO initiated the VOS
Special Observing Project — North Atlantic
(VSOP — NA) to address these latter aspects.
This three-year study of the effects on ship
observations of different instrumentation and
observing practices involved 46 vessels from
Expendable bathythermographs sample the structure of the
upper layers of the ocean.
the voluntary observing fleet and has
provided a great deal of invaluable
information2. A related, more recent, initiative
has targeted the creation of a high quality
reference set of ship observations for climate
applications — the so-called “VOS subset for
climate”.
2 Its success is largely attributable to the committed
efforts of the Masters’ and ships’ companies who
participated in the study.
THE IMPACT OF ADVANCES IN OBSERVING
TECHNOLOGY
Recent technological advances have made it
possible for volunteer observers to carry out
complex observational tasks previously
performed by meteorological and
oceanographic specialists. As a result,
voluntary shipboard observing programmes
have expanded to include observations of the
upper atmosphere and subsurface
oceanographic measurements from a
relatively small number of specially selected
ships. Under the aegis of WMO’s automated
shipboard aerological programme (ASAP),
radiosonde ascents from commercial vessels
have grown to around 5 700 annually,
enhancing the accuracy of meteorological
analyses over the oceans. Similarly,
expendable bathythermographs (XBTs)3
deployed from vessels participating in the
IOC-WMO ship-of-opportunity programme
(SOOP) observe the structure of the upper
layers of the oceans along their routes.
Processed XBT data are relayed via the GTS to
meet operational needs4 while the original
XBT measurements are collected at the end
of each voyage, quality controlled and
archived in designated global data centres for
use by the global research community.
3 Expendable bathythermographs sample the water
column as they sink, relaying thermal data to a
shipboard processing unit via a thin copper wire. At
present, about 100 vessels participate in the SOOP.
Most are also VOS participants.
4 These include climate monitoring and prediction,
fisheries, shipping and defense applications.
The Contracting
Governments undertake to
encourage the collection of
meteorological data by ships
at sea and to arrange for
their examination,
dissemination and exchange
in the manner most suitable
for the purpose of aiding
navigation.
General Regulations determined by
the International Conference on
Safety of Life at Sea, London, 1960,
Regulation 4(a), Chapter 5.
Volunteer observer David
Vail of MV Bluerose
receiving an award from
Canadian PMO Randy
Shepherd.
CURRENT CHALLENGES AND FUTURE
DIRECTIONS FOR THE VOS PROGRAMME
Despite its undoubted successes, it is clear
that the WMO VOS scheme faces some
significant challenges. VOS reports are
heavily concentrated along the major oceanic
shipping routes. Large data-sparse areas exist
in oceans in the southern hemisphere and in
high latitudes. Relatively few observations are
received from coastal waters and harbour
approaches. VOS numbers have been
declining and changes in global shipping
practices have made recruitment more
difficult. Today’s modern ships are increasing
in size and becoming highly automated. Crew
size has been substantially reduced, leaving
less time available for voluntary observing
duties. Furthermore, the new climate
modelling and long-range forecasting
priorities impose pressures for enhanced
observational distribution and accuracy.
The need to address these challenges
points to four priorities for the future
evolution of the VOS programme:
(a) The decline in numbers of participating
vessels must be arrested. To that end, the
attention of shipping companies, ships’
officers, navigation schools and colleges
must be drawn to the vital contribution
made by VOS to marine safety and
efficiency, to the prevention and clean-up
of marine pollution, to operational
planning, vessel design and to the
advancement of our understanding of the
climate system;
(b) Additional VOS must be recruited in datasparse ocean areas and increased
reporting encouraged in coastal waters.
This will require more active involvement
of countries with expanding registers of
shipping5, reinforced by substantial
capacity building support to developing
countries adjacent to climaticallysensitive ocean regions6. Equally, as
hydrocarbon and mineral development
steadily expands into “frontier” ocean
regions, efforts must continue to obtain
additional observations from icebreakers,
supply vessels, oil rigs and other coastal
and offshore platforms;
(c) The introduction of software packages
and automated observation systems must
be accelerated to reduce workload and
minimize errors in coding and
transmitting VOS reports. Such systems
have the potential to arrest the decline in
numbers of VOS, encourage recruitment,
improve data quality and reduce
operating costs;
(d) Requirements for observational data to
document climate variations and climate
change and to validate climate model
predictions may be expected to continue
indefinitely. Consequently, continuing
attention must be paid to ensuring
enhanced coverage and accuracy of VOS
observations.
5 Increasingly, the world’s sea-borne commerce is carried
in vessels operating under “flags of convenience”
registered in developing countries or crewed by their
nationals.
6 Countries with well-developed VOS fleets are ideally
placed to provide practical assistance.
CONCLUSION
Meteorological observations from VOS
continue to make a vital contribution to
marine safety and efficiency, providing realtime reports needed for weather forecasting
and historical data needed for planning and
design. They contribute substantially to
increasing our understanding of the
atmosphere — ocean linkages, essential in
addressing the issue of global warming and
for the development of accurate long-range
weather forecasts. They also provide vital
ground truth measurements for the
calibration of satellite observations. These
realities will remain unchanged in the
foreseeable future.
The VOS and its sister programmes
represent a highly cost-effective approach to
oceanic data collection. At a time when
demands for observations from the oceans
are increasing, they also possess significant
potential for expansion in climatically
important, data sparse, regions. Realization
of this potential will, however, require
investments in capacity building, in vessel
recruitment, in software development and in
automated observing systems. It will also
require the continuation of the long tradition
of voluntary ocean data collection by the
world’s seamen which has made the VOS
programme such a classic example of
enlightened cooperation and enduring
partnership.