We cannot control the weather, but it can certainly control us. The impact of adverse conditions on air traffic can be severe, and although such conditions cannot be eliminated, through improved systems and processes for meteorological sensing, warning and planning, the effect of adverse weather on flight efficiency and safety can be mitigated.
Given the current drive in the industry to reduce delays and optimise the use of airspace through improved traffic control, parallel improvements in meteorological data gathering and distribution are a necessity.
Olli Marius Turpeinen, chief of meteorology for the International Civil Aviation Authority (ICAO) says, "With growing traffic volume and the congestion that occurs, we must optimise the use of airspace."
"One of the most important challenges to the meteorological service for international navigation is how to upgrade to meet those challenges."
These efforts need to focus on many different fronts, both for facilities on the ground and for aircraft en route. The quality of meteorological information can have a major effect on the capacity of airports, the efficient management of routes and the safety of aircraft in the air.
This is especially important now that the required vertical separation of aircraft in certain jurisdictions, notably Europe, has been halved to 300m. "This means there is less margin for error, so we must reduce possible errors wherever possible," says Turpeinen.
TAKING TECHNOLOGY FORWARD
Investment in technology is a key factor in moving weather data gathering and distribution forward. More sophisticated remote sensing technology could play an important role, certainly in improving the quality of information at aerodromes.
Facilities on the ground can augment visual observation with longer-range scanning to increase the accuracy of weather reports and extend their range.
"Improved accuracy is an important goal for the technology that is developing," says Turpeinen. "It relies on increased use of automation, which, by and large, has a positive impact on accuracy, and provides information that is more consistent than data from human observers."
Bringing this technology into more widespread operation, however, is less a question of systems development than of investment in the technology that is already available.
After all, ground-based weather radar has been available for decades, but the cost of implementing such systems has prevented their wider use. There is understandably a reluctance among airlines to bear the full cost of implementing remote sensing technology, particularly as the information gathered could be used in a different sector, to provide weather forecasting services for the general public, for example.
Cost is also a major obstacle to systems implementation in the developing world. While the technology does have a return on investment in terms of improved efficiency, this return only accrues over a long period of time.
The issue of cost confronts the global industry when it comes to
plans for improving meteorological information streams. It is reassuring, then, that the main demand on technology in the short-term is not so much the improvement of data gathering, but the better use of existing data.
"The challenge is to provide information that is operationally useful and representative for any area of concern," says Turpeinen. "Technology is key here, and in this specific area it is delivered through the greater use of remote sensing along with situational observations." Integration of ATC centres with meteorological data flows is therefore a prime concern for ICAO.
EN ROUTE WEATHER DATA
While sharing information among ground-based facilities is a priority, so is addressing weather-related issues for aircraft en route.
ICAO has identified a number of specific areas where improvement is highly desirable. Key among these is the area of volcanic ash.
As an example of how ash can affect the airline industry, one need only examine an eruption in Iceland in November 2004, which affected Europe's airspace dramatically, forcing large areas to be closed. This resulted in many delays and much greater congestion, as the industry, necessarily, erred on the side of caution in its attempt to balance efficiency with safety.
Turpeinen says, "The challenge is to define what is an acceptable level of ash and establish a threshold where it has little impact on aviation. At the moment, the advice is that any ash is to be avoided. This disrupts air traffic for hours or days, so there is much work needed."
Many other questions need to be addressed, such as the timeliness
of warnings and the need to notify aircraft of eruptions and ash clouds as early as possible. Scientific advances are required, ICAO believes, in order to define the parameters and characteristics of an eruption.
ICAO identifies a need for more sensors near active volcanoes and greater cooperation with state authorities that may already be monitoring key sites.
Again, cost is a thorny issue that is hindering progress, but Turpeinen points out that investing in a solution is a better use of money than reacting to problems once they have arisen.
To show that delays caused by ash clouds have a major cost impact, he cites recent research that suggests that inadvertent aircraft encounters by five aircraft with volcanic ash from the eruption of Miyakejima in Japan in 2000 caused three airline operators to incur costs of over $12m, as well as losses in operating time.
"This information illustrates the potential for savings if improvements are made to the ICAO international airways volcano watch," he says. "There are huge costs related to the inadvertent penetration of ash clouds, so you could deploy many more sensors and still make savings."
IMPROVING THE FLOW OF DATA
The development of the World Area Forecast System (WAFS) for new airspace requirements is a key project for ICAO.
The project centres on further specific problems that aircraft can encounter en route and aims to deliver accurate forecasting of factors such as icing, turbulence and convective cumulonimbus clouds. All of these have a significant impact on safety as well as on the efficient use of airspace.
Improving the quality of data in these areas is part of ICAO's development goal for WAFS, although improvements in the science of understanding these phenomena are needed, alongside improved information sharing.
A WAFS unit is working to get the science right and then developing the appropriate software to use this information in a constructive way. The demands on WAFS are likely to grow as the industry demands not only more detailed information, but also accurate forecasting for extended periods.
"There is a question of the industry wanting longer-range forecasts," says Turpeinen. "At the moment, the longest is 30 hours, but Eurocontrol wants reports two days in advance, so 48 hours ahead. It is not a formal request yet, but we are anticipating it. This means increasing the resolution of the WAFS forecasts to enable industry to reduce errors in flight plans and flying times."
Once again, the issue of cost raises its head, as more data channels will be required and new software will need to be developed. Securing these developments will rely greatly on coordination between ATC and the meteorological authority.
The stream of data from meteorological office to ATC to aircraft and then back along the chain is a crucial area for development. The involvement of all stakeholders, from the meteorological office to the airlines and the regional authorities such as Eurocontrol, is vital.
"The main problem is not standards, but the effective implementation of existing standards, in particular improving the data link for passing on routine information, so that non-routine messages flow more smoothly," says Turpeinen.
ICAO is concentrating on the development, management and coordination of WAFS and the Satellite Distribution System (SADIS) for information related to air navigation, which incorporates efforts to uplink and downlink meteorological information to aircraft using air-to-ground data links.
This initiative is also being linked to the development of warnings for air turbulence, information from the international airways volcano watch and the tropical cyclone warning system.
WAFS data is a key part of the tactical decision-making process of ATC operators, particularly for dynamic aircraft routing and in-flight re-planning. SADIS, which is mostly used for flight planning, is increasingly important and access to the data it provides is being simplified – more users are now accessing the web-based version, which was originally intended only as a back-up system.
All this suggests that the appetite for improved data is being matched by development efforts, as the importance of the meteorological function in planning the dynamic use of airspace grows.
Provided all stakeholders continue to participate and cost issues can be overcome, the industry could soon get the quality of weather data it needs as it adopts a new paradigm for airspace management.