Northern New Zealand will experience more droughts due to a change in Southern Ocean winds. A new study by the Australian National University revealed stronger westerly winds from the ocean. The force is believed to be stronger than any time in the last 1000 years. The winds are moving southwards and were observed to be concentrating around Antarctica.
Lead researcher Dr Nerilie Abram said the strong westerly winds were trapping the cool air in Antarctica which meant less rain for New Zealand and southern Australia. Dr Abram said the climate in New Zealand is "very sensitive" to westerly winds, storms and rainfall that come from the Southern Ocean.
She said if the westerly winds will continue to move further south, New Zealand will experience less rain and prolong the dry season. Dr Abram told APNZ New Zealand that although New Zealand remains in the path of the winds, more droughts will be largely felt in the northern regions of the country.
Victoria University's Dr James Renwick said the shift in westerly winds has been observed for several years but the new study has confirmed the trend. He explained that storms and rainbands usually follow the location of the winds. With the westerly winds moving further south, this will mean a greater chance of droughts in the North Island.
Dr Renwick said the possibility of drought in North Island has increased in the next few decades. New Zealand will be drier during the summer. He added that strong southern winds were also affected by the hole in the ozone layer. The hole provides a cooling effect at the pole which only contributes to a great temperature difference.
Aside from New Zealand, the study published in Nature Climate Change also revealed that rising levels of carbon dioxide in the atmosphere were strengthening the winds in the Southern Ocean which usually bring rain to Southern Australia. However, the carbon dioxide has pushed the winds closer to Antarctica. Dr Abram also said the findings were not good for Australia as the rise of greenhouse gases in the atmosphere will only result to bringing less rain in the country.