Airport Thunderstorm and Lightning Alerting System (ATLAS) - Lightning Protection at the Airport
In mid-2007, the Hong Kong Observatory began operation of the Airport Thunderstorm and Lightning Alerting System (ATLAS) to support the Red Lightning Warning at the airport. ATLAS has proved to be an improvement over the earlier system and contributed towards minimising the risk of lightning to ground staff when working under these conditions. Tracking the movement of radar echoes and lightning activities, the system forecasts the time when lightning is expected to affect the airport.
ATLAS generates an AMBER warning whenever cloud to ground lightning, or C-G, is predicted to affect the 5-km perimeter from the aerodrome or when intense radar echoes are within 15 km and C-G lightning is detected or predicted within 5 km. During an AMBER warning, all non-essential activities on the airport apron are suspended. A RED warning is generated whenever C-G lightning is affecting or predicted to affect within 1-km of the airport island. During a RED warning, all personnel on the apron are advised to take protective shelter from the storm. Passengers should also stay inside sheltered areas such as aircraft and Passenger Terminal and follow the instructions of airport and airline staff. As a result of cessation of apron activities, waiting time for passenger embarkation/disembarkation and baggage reclaim may be prolonged.
ATLAS was put through its paces earlier this year when an intense thunder-bearing storm approached the airport from the northwest on the evening of the 25 April. Figure 1 shows the lightning strikes as detected by the Hong Kong Observatory Lightning Information System (LLIS) together with the radar picture at that time during the episode. The storm affected the airport for around 2 hours and for much of that time ATLAS issued the RED Lightning Warning.
While due to the weather situation, the duration of RED Lightning Warning might be prolonged at times causing inconvenience to passengers, the ATLAS was implemented to ensure the safety of passengers and airport staff. All personnel on the apron are advised to follow the guidelines as stated in the Emergency Procedures Manual published by the Airport Authority Hong Kong.
Figure 1 Thunder-bearing storm at 9:29 pm on 25 April 2012 affecting the Hong Kong International Airport. The ellipses designate strike clusters identified and monitored for their movement. At the time of the image the RED warning was in effect.