BAZflyer: Crossing the Climatic Equator

As a round the world and long-range flyer, Bazflyer is often asked; “What do you do while sitting in a small aircraft cockpit for eight or nine hours?” Well, the brief response is to say that it is by no means boring. Monitoring, checking and re-checking flight progress against the plan is a constant process. Engine parameters, ground speed and fuel consumption data are consistently reviewed. Then there are regular radio calls to make giving portion reports to the monitoring agency responsible for the airspace you’re flying in. High Frequency (HF) radio is commonly used to do this usually communicating with an operator thousands of miles distant. This was the case yesterday while flying eight hours from Mount Hagen north of the equator to the island of Guam. The radio operator was on the other side of the Pacific Ocean in San Fransisco.

As well as the routine procedure of flying, a pilot also needs to be cognisant of the environment and yesterday that entailed penetrating and crossing the ever present Intertropical Convergence Zone (ITCZ). This band of equatorial weather is one of the most fascinating and influential features of Earth's atmospheric dynamics. Often referred to as the "climatic equator," this region plays a crucial role in shaping weather patterns and influencing the climate across the globe. But what exactly is the ITCZ, and why is it so important?

The ITCZ is a belt of low pressure that circles the Earth near the equator, where the trade winds from the Northern and Southern Hemispheres meet. This convergence of winds results in a band of intense cloud formation and precipitation. It is not a fixed line; it migrates north and south with the seasons, following the sun's zenith point and influences the monsoon systems in regions such as South Asia, West Africa, and Central America. Understanding the behaviour of the ITCZ is crucial for predicting weather patterns and managing water resources.

Prior to commencing yesterday’s flight, satellite imagery provided Bob and Baz with advance knowledge of where the ITCZ was sitting. Even so, visually picking a safe route through this band of weather was another series of decisions and tasks added to the busyness of everything else. Next time the ITCZ is encountered it will be on the way back from Guam to Papua New Guinea, following an historic global circumnavigation and World Flight 100. Never let it be said; “Flying round the world in a small airplane is ever boring.”