By using computer model analyses, the past 72-hour backward trajectory of the air mass reaching Hong Kong is estimated by the Observatory on a daily basis. The daily trajectories are compiled into the Monthly Backward Trajectory Map. The Monthly Map for March 2012 is now available on the following webpage:
In March 2012, the air masses reaching Hong Kong mainly originated from the east and northeast, indicating that the territory was influenced by the interchanging northeast monsoon and humid maritime airstreams.
Backward Trajectory of Air Mass reaching Hong Kong in March 2012
For Daily or Seasonal Backward Trajectory Maps, please visit the following webpages: