Heat waves, sometimes called extreme heat or spelled as heatwave, are natural disasters that pertain to abnormally high temperatures and a prolonged period of excessive hot weather.
It can occur at any time of the year, especially during the summer season of a particular region, which is common in countries along the tropics and equator.
In New Zealand, summer heat waves in recent years have been detrimental to the environment, ranging from glacier melt to marine animal deaths due to ocean warming, according to a new study led by scientists from the Victoria University of Wellington in New Zealand.
The researchers involved in the paper said the extreme summer heat has produced "dramatic" climate impacts.
New Zealand Heat Wave Study
AUCKLAND, NEW ZEALAND - JANUARY 06: Alexis Van Niekerk, 8 of Hatfields Beach cools off in the Wynyard Wharf water sculpture on January 6, 2014 in Auckland, New Zealand. Auckland is expected to cool this week, after yesterday humidity reached nearly 100% in some areas.
The said heat wave study in New Zealand suggested that the extreme heat in recent summers are already causing different effects on the environment such as marine heat wave conditions in the northwestern and southwestern waters of the country.
The findings from the previous austral warm seasons saw the region experiencing the most intense oceanic and atmospheric heat waves on record, wherein atmospheric circulation anomalies over land and sea spiked as high as 1.2 to 1.4 degrees Celsius above average.
The results are based on the study published in the journal Weather and Climate and is available on the website of The Meteorological Society of New Zealand.
New Zealand Summer Heatwaves
The New Zealand summer heatwaves from 2017 to 2022 reportedly saw the warmest months on record with over 25 degrees Celsius.
The "warm season heat waves," which spans from November to March all triggered dire climate impacts nationwide, including marine heat wave conditions and significant glacier melt in the Southern Alps, according to Dr. Jim Salinger, the study's lead author and researcher at the Victoria University of Wellington, as cited by Phys.org.
Earlier this year, reports have emerged that the intense heat in New Zealand is already taking a toll to marine ecosystems, where the death of fish populations and other marine organisms can make their predators starve.
The waters around the country are up to 6 degrees Celsius warmer than normal because of climate change, as well as the La Nina weather phenomenon and a cascade of high-pressure systems, according to scientists, Reuters reported.
The Moana Project said that waters surrounding the West Coast of the South Island are currently 4 degrees above normal as of January 2023.
Heat Wave Risks
Aside from environmental disasters, heat waves are also responsible for multiple deaths in recent years, including the catastrophic, deadly 2022 European heat waves that killed over 20,000 people.
For this month, the Moana Project issued its New Zealand marine heatwave forecast, suggesting strong marine heat waves are persistent in the Cook Strait, Otago Peninsula, and Stewart Island from Thursday, May 4, to Thursday, May 11.
This comes as coastal water temperatures across the region reached an excess of 1.5 to 2 degrees Celsius above normal.
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