Quantifying the disruptive impact of CAPE (Convective Available Potential Energy) on air traffic flows through UK airspace.

Concern about the environmental impact of aircraft operations is currently high on political and scientific agendas. However, while the relationship between aircraft emissions and climate change has been systematically investigated, far less is understood about the impacts future climate change may have on the aviation industry. While a number of potential impacts of climate change, including sea level rise and temperature changes, on the aviation sector have been identified, there is a dearth of original research that explicitly analyses the infrastructural and operational threats a changing climate may pose to the UK's commercial aviation sector. One of the anticipated outcomes of climate change is an increase in thunderstorm activity.At present, thunderstorms, and associated convective weather activity, represent a major source of air traffic network disruption. The atmospheric environment in and around a thunderstorm represents one of the most hazardous airborne environments an aircraft may encounter, while on the ground, thunderstorms and associated atmospheric phenomena have the potential to close airports, reduce runway capacities for landings and take-offs, and hinder or prevent normal ground servicing and flight turnaround operations. Though the sophistication of modern meteorological forecasts and weather radar means that the location and intensity of storms can be predicted, located, and often avoided with increasing accuracy, a significant number of fatal aircraft crashes have been attributed, at least in part, to aircraft encountering adverse weather conditions in the take-off, en-route, or final approach phases of a flight. Most pilots endeavor to avoid known areas of thunderstorm activity by requesting alternative headings and/or flightlevels and will often accept significant deviations from their submitted flightplans to avoid the most turbulent areas of the atmopshere. This practice almost inevitably results in longer flight times, higher emissions, and greater operating costs for the airlines concerned. By studying the effect of convective weather on air traffic flows through a carefully selected region of UK airspace, this research will address a significant gap in the existing knowledge base. It will quantify the effects of convective weather on air traffic flows in terms of increased fuel burn and emissions and will establish a minimum threshold for CAPE (Convective Available Potential Energy - a measure of energy and a proxy for levels of turbulence in the atmosphere) in J/kg above which disruption to normal air traffic flows is experienced. Then, using future CAPE meteorologies for 2020, 2030, and 2040, the research will assess the likely impact of climate change (in terms of frequency of CAPE threshold exceedence) on air traffic flows through UK airspace. The findings of the research will be of value both to the UK and to the air navigation service providers of overseas nations as it will help them plan for future network disruption thereby minimising costs to users.

The research will deliver cutting edge insights into the impacts of climate change on the UK's commercial aviation sector by establishing a minimum threshold for CAPE (Convective Available Potential Energy, a proxy for turbulence in the atmosphere) above which disruption to air traffic flows is experienced. Then, using future CAPE meteorologies for 2020, 2030, and 2040, the research will analyse the likely implications for the aviation industry of any changes in the frequency with which this threshold is exceeded. Key beneficiaries include air transport decision-makers and aviation regulators, airline industry stakeholders, and academics (see academic beneficiaries section), both in the UK and overseas. It is anticipated that the research will have both an immediate and a longer-term impact on air transport operations, air traffic management, and inform future policy responses to climate change. Within 5-10 years, it is expected that the research may benefit airline passengers by enabling airline industry stakeholders to better prepare for, and mitigate, the effects of future weather-related network disruption and encorporate new flight planning guidelines into their standard operating procedures, thereby simultaneously reducing passenger delays and improving safety. The research will provide vital information to UK Government Departments and aviation industry regulators. The findings will be of direct relevance to the Department of Transport (DfT), the Civil Aviation Authority (CAA), and the UK's Air Navigation Service Provider (ASNP), NATS. The findings will also have broader implications for international agencies including Eurocontrol, the individual ANSPs of overseas nations, IATA (International Air Transport Association) and ICAO (International Civil Aviation Organisation). The research also has the potential to inform the work of a diverse range of aviation businesses and professional bodies including, but not limited to, individual airlines, airport operators, air traffic control providers, and ground handling agents in both the UK and abroad. Strong industry support for the project has already been expressed by the Air Traffic Services Manager at Manchester Airports Group, the Head of Health, Safety, and Environment at BAA Stansted, the Head of Environment at Eurocontrol, and a senior research analyst in the environment division at NATS (see accompanying letters of support).