The phenomenon which created an orange haze was known as cloud condensation nuclei (CCNs).
CCNs were small particles typically 1/100th the size of a cloud droplet which water vapour can condense on.
The smoke particles in the atmosphere above the North Island were acting as this non-gaseous surface to make the transition from vapour to a liquid.
MetService meteorologist Tahlia Crabtree explained the process when smoke altered the atmosphere in the South Island last week.
"They're little particles in the air and they're big enough that they can interact with the light from the sun which is why it ends up looking quite hazy, scattering the light," Crabtree said.
"The brown or orange tinge is due to the fact it tends to scatter light at the blue end of the visible light spectrum which means eventually the reds and oranges are more significant.
"Especially at sunrise and sunset there is more of the troposphere, the upper atmosphere, that the light has to travel through, and if there's a lot of smoke there's a lot more scattering."
The sun tries to break through the clouds amid smoke and haze from the Australian bushfires. Photo / Dean Purcell
The revelation comes amid warnings people with respiratory conditions could experience trouble breathing because of the smoke.
Asthma and Respiratory Foundation chief executive Letitia Harding said there hadn't been any official reports of increased respiratory problems yet, however, people with respiratory conditions should always be mindful of potential risks.
"If you have a respiratory condition, you should ensure that you keep your medication with you at all times," Harding said.
