Hadley is a name that all geographers will come across at some point. George Hadley’s name always pops up in school during GCSE or A-Level or perhaps from the weather forecasts on the news. But who was he, what did he do and why is he well known?
George Hadley grew up in London – born on 12 February 1685. In 1700, he went to study at Pembroke College, Oxford, paid for by his father. While he was pursuing a degree in Law, he found himself more interested in the mechanical and physical sciences. He was placed in charge of interpreting meteorological data diaries. He carried out this task for 7 years, ensuring the data was sent to the Royal Society. It was then analysed by observers based across the globe.
What did George Hadley do?
Hadley focused on deducing patterns in temperature and pressure patterns and discovered a few general trends. He published a short paper in 1735 which discussed his explanation for the trade winds. Wind systems that operate on each side of the equator. His discovery was more or less forgotten. Several meteorologists proposed the system of the trade winds and it wasn’t until the later half of the 19th century that Hadley became recognised for first concluding their use and explanation of why they occurred.
Hadley’s theory to explain the trade winds was based on recognising the role that the Earth’s rotation plays relative to air masses. It was later concluded that this effect was more conducive to the Coriolis Effect than the trade winds.
While his suggestion may be incorrect and disproved, Hadley remains a key figure in meteorology. Within weather forecasts and the education sector, the Hadley Cells are often referred to and have great significance. These air cells are those that operate on either side of the Equator, including the trade winds – a recognition of his previous theory.
There is also a Met Office centre named after him, commemorating his contributions to the field.
Hadley Cells are low-latitude circulation systems which move low-pressure air at the equator vertically upwards, denser and cooler. The air is then transferred towards the poles where it sinks in an area of high pressure. The air sinks at around 30° latitude.
The Hadley Cells are responsible for the North East and South East Trade Winds in the Tropics which produce many weather patterns. There is one cell in each hemisphere.
Overall, Hadley’s conclusions were remarkable and his work has not been forgotten. He paved the way for other meteorologists to discover the workings of our atmosphere and his work has been greatly developed on.