EUMETNET Automated Shipboard Aerological Programme (E-ASAP)
The EUMETNET Automated Shipboard Aerological Programme (E-ASAP) is a fully integrated component of the EUCOS Operational Programme. Programme management responsibilities rest with the Deutscher Wetterdienst (DWD). The Programme Management is assigned to Rudolf Krockauer.
Vertical profiles of wind, temperature and humidity from radiosondes are essential for the analysis of the state of the atmosphere. This is due to their all-weather capability to measure detailed vertical structure which the space based soundings are not expected to measure for many years to come. The interim results from the EUCOS sponsored Terrestrial Study confirm the value of radiosonde soundings in regional NWP. At present, soundings from commercial and research vessels (ASAP) and oil platforms are the only source of profiles over the ocean areas of interest for short to medium range NWP over Europe.
An ASAP system is a radiosonde station designed for operation on board of ships. The system essentially consists of the balloon launcher and the sounding system. The original objective of E-ASAP was to operate 25 ASAP systems producing 9000 soundings per year by 2010. However, due to financial restrictions this target was reduced to 6300 soundings from 18 ships in 2006, based on an assumption of 350 soundings per ship, per year. Experience has shown that this target is too ambitious for all the ships in the E-ASAP fleet and, as a consequence, the overall target of 6300 soundings per annum cannot be met.
Follow this link to watch a Movie of an ASAP ascent and read the article ‘Weather observations’, reproduced from Seaways, December 2009. Seaways is the journal of The Nautical Institute (www.nautinst.org).
During the 2003-2006 period, the main objective of the E-ASAP Programme was to achieve 6,300 soundings per year from 18 ships. Towards the end of this programme phase it was clear that the objective was too ambitious and had to be reduced to 5,440 soundings from 17 ships in 2006. Reasons for the reduction were:
ASAP container launchers
- Higher operational costs per sounding than assumed;
- Higher loss rate of launches than expected;
- Less available sounding days per ship than assumed;
- Problems in acquisition and maintenance of vessels.0
In line with the EUCOS Programme Plan, the E-ASAP Programme objectives during the 2007-2011 period will be:
Key Objectives:
- Deliver 4700 soundings (from 19 ships) onto the Global Telecommunication System to make the data available to all National Meteorological Services;
- Fully compensate the costs of national ASAP stations (which are operated by some European Meteorological Services on a national level) by 2011;
- Offer competence and financial compensation to National Meteorological Services to establish a suitable support and maintenance network in various European ports;
- Produce added value for the forecast models.
Most of the ships in the E-ASAP fleet are container ships in line service in the North Atlantic between Europe and North America. Every now and then reliable ASAP ships have to terminate their participation due to changes in the line service or other reasons. In the case of surprising decommissions an efficient management and timely return of the ASAP stations from seaports on both sides of the Atlantic to Hamburg is required. This is only possible through the active co-operation of ship crews, ship managers, and local sub-contractors (e. g. truck companies, crane services etc.). The same applies when it comes to the selection and installation of ASAP systems on board of replacement ships.
In 2008 E-ASAP fully supported the prototype of the so-called DTS (Data Targeted System). The DTS aimed to provide additional observations in sensitive areas, depending on the actual weather situation. Special communication links were established to enable the DTS team at the European Centre for Medium-Range Weather Forecasts to request extra soundings from the ASAP ships. The prototype ended in December 2008 but E-ASAP is prepared to continue with targeted observations as soon as the DTS becomes operational.
Due to changes in software, hardware, and training, the output (percentage of the number of received data divided by the number of launched balloons) could be improved. Most ships sail with speeds of 15-20 knots which produces difficult launching conditions due to turbulences, head/tail winds etc.. A number of balloons burst at launch. Also the satellite communication remains a source of failure. Not to mention the permanent vibrations from the ship’s machinery which reduce the lifetime of the equipment. But the effort is worth since ASAP soundings are the only source of upper air data over the oceans.