Overview
The primary goal of the Automated Shipboard Aerological Programme is to collect reliable data baseline upper-air data from remote ocean areas in a cost effective way.
The ASAP in its present form began in the mid-1980s. It involves the generation of upper air profile data from data sparse ocean areas using automated sounding systems carried on board merchant ships plying regular ocean routes. The profile data are all made available in real time on the GTS, for use by operational centres.
ASAP is of vital importance to both the WWW and GCOS. Several National Meteorological Services operate ASAP units, and the programme is coordinated through the ASAP, a component of the JCOMM Ship Observations Team. Most of the soundings are presently from the North Atlantic and North West Pacific Oceans, but the programme is also expanding into other ocean basins, most notably through a new, cooperative Worldwide Recurring ASAP Project (WRAP). The ASAP publishes an Annual Report, giving programme status and statistics on data return and data quality.
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1. Introduction
The primary goal of the Automated Shipboard Aerological Programme is collect data baseline upper-air data from the oceans. As part of the global observing system, ASAP data can be used to support many applications, including global climate studies.
ASAP is establishing itself as an operational programme and is therefore participating in the Joint WMO-IOC Technical Commission for Oceanography and Marine Meteorology (JCOMM) and particularly in its Ship Observations Team (SOT). Data management is taken care of through the Global Temperature Salinity Profile Programme (GTSPP).
2. Background
ASAP in its present form began in the middle of the 1980s and was organized by the World Meteorological Organization’s ASAP Coordinating Committee. In recent years the responsibility for coordinating the overall implementation of the programme, including monitoring its overall performance, both operationally and in respect of data quality, passed to a Ship Observations Team (SOT) established by the Joint WMO/IOC Technical Commission for Oceanography and Marine Meteorology (JCOMM).
The original ASAP system was developed as a modular ‘containerised’ unit that could be quickly installed on, or removed from, a host ship. The system was completely housed within a specially modified standard 6.1 metre (20 foot) shipping container. This container included all necessary electronics and antennas, the balloon launching system, stowage for consumable supplies such as helium, balloons and sondes, and adequate operator workspace. It only required a suitable open deck space and connection to the ship’s power supply.
In recent years an alternative system configuration, known as a ‘distributed’
system, has been developed to expand the versatility of the ASAP concept.
Distributed systems are essentially limited to the required electronics which are installed in existing ship
spaces accessible to the operator, usually on the bridge or nearby.
Manual or remote launching techniques are employed and the consumable supplies are stored in an
appropriate onboard space.
Alternatively a 3.05 metre (10 foot)
container is now often used for both
launching and stowage purposes.
The ASAP programme aims to be cost-effective
The capital cost of the containerised ASAP system was found to be equal to or less than that for a new landbased aerological sounding station.
3. Data
The quality of ASAP data
is generally found to be
very high, comparable to
the quality of data from
dedicated ocean weather
ships, with sounding
heights exceeding 20
kilometres.
The quantity and quality of
data collected in real time
and transmitted over the
Global Telecommunication
System has shown significant improvement since the early years of ASAP. The
total number of ASAP soundings has increased to approximately 5 000 annually
(see figure).
The majority of national programmes have now adopted the Inmarsat C system
for transmitting data. This system has approximately 99 per cent
communications efficiency, allowing data to be communicated as effectively as
other upper-air data on a worldwide basis.
The Global Positioning System (GPS) and Loran are now the most commonly
used systems for determining radiosonde speed and direction.
Go to the ASAP Monitoring Page
Factors to consider when recruiting a new ship, here
5. Future Aims
To work effectively with countries
adjacent to data-sparse ocean
areas to find potential ASAP
operators with routes through
these areas;
To encourage joint ventures to
implement new ASAP observing
programmes;
To continuously analyse, evaluate
and implement more costeffective
means to communicate
ASAP data;
To provide best practice, advice and assistance
to new ASAP operators;
To improve efficiency in
communicating data;
To design more robust, automated and deck-based launching devices.
5. Contacts
Link to points of contact |
