Ah, spring: a time of new life and old arguments. Shane Gilchrist searches for seasonal signs.
Let’s talk about spring.
More specifically, let’s discuss the timing of the season, a subject as perennial as wobbly-legged lambs or the sprays of floral colour that offer signs of new life as the sun warms the soil.
For some, including meteorologists and media, spring began on September 1.
For others, including astronomers, it will arrive with the equinox this Friday, September 23, when daylight and night-time share 12 hours each.
There’s certainly nothing official about the September 1 date.
There is no legislation covering seasons in New Zealand.
That’s not to be confused with the Department of Internal Affairs’ legislative responsibility for defining daylight savings, which begins next Sunday, September 25.
Meteorologist Philip Duncan, founder of New Zealand website WeatherWatch.co.nz, says he’s privy to arguments every time there’s a change of season.
"Debate fires up over just why we start and end our seasons earlier than most other countries.
"Many argue the September 1 date makes no sense, that it is the sun and Earth’s axis that define the seasons. The thing is, there is really no single answer to it," Duncan says.
"I looked into this about 10 years ago when I started up Weather Watch. I had always thought spring began on September 1, largely because television and other media had talked about it. Then I got all this push-back from people, so I asked around and it was explained to me that it had do with the astronomical and meteorological dates."
He went so far as contacting the Department of Internal Affairs, asking if there was an official start date for the seasons.
The answer: there is no agency, or law, responsible for regulating seasons.
"Because there is nothing official resulting from legislation or regulation, then it might be an issue that needs to be raised informally, for example, through community forums and debate."
Or newspaper articles.
Why did we arrive at a first-of-the-month seasonal demarcation?
It has to do with statistics and simplification, Duncan says.
"When weather record-keeping began in the 1800s, it was much easier to keep records by using entire months."
The elliptical path of Earth’s orbit around the sun every 365.24 days means the length of the astronomical seasons varies (between 89 and 93 days).
For meteorologists, these variations in seasonal duration present problems when comparing climate statistics.
Hence, the meteorological seasons are broken into groupings of three months (from 90 days for winter in a non-leap year to 92 days for spring and summer).
Less variation equals easier statistical analysis.
Duncan says he has conducted a range of polls over the years and the majority of respondents have preferred their season to begin on the first day of the month.
"In a recent poll, 38% said they believe each new season kicks off at the start of the month. Of the other 62%, just 26% supported the astronomical dates around the equinoxes and solstices and 36% agreed, ‘It doesn’t have a date, it arrives when it arrives’."
Spring is the most talked about season, he says. Much of this hot air has to do with New Zealand’s changeable climate.
"I often say there are three dates to spring: the astronomical date, the meteorological date, and when mother nature feels like she’s ready to start.
"I think New Zealand actually has about eight months of spring and autumn; the rest of the year comprises a two-month summer and a two-month winter.
"New Zealand largely comprises two small islands, one in the Roaring Forties and one in the subtropics. We don’t really have a long-lasting summer, nor do we have a long winter. Every single season in New Zealand can be skewed by one single air-pressure system. That’s another reason why it’s so hard to fully define seasons here.
"People think spring is warm, that the snow has finished, the frosts are done. Then, when there is a weather event like that storm last week, their expectations become confused."
Ian Griffin, director of Otago Museum, has more than 25 years of experience as an astronomer, including heading Armagh Planetarium, in Northern Ireland, and the Auckland Observatory.
He enjoys this time of year, largely because it means he can engage in some gentle arguments.
"I always have people on. When they say spring has arrived, I tell them it hasn’t. Then when you get a cold blast like we did last week ... I was madly pointing out the error of everyone’s ways.
"There’s been a lot of discussion about the date that spring begins. Some claim that September 1 is the first day of spring; as an astronomer, I’d prefer it to start at the equinox, which this year is September 23.
"Essentially, most weather patterns are driven by the sun, at a really gross level; that’s not true on a daily basis.
"As the sun gets higher in the sky and heats the oceans, certain weather patterns result. The position of the sun in the sky is as good a way as anything to defining the start and end of seasons."
Yet there is another argument that says the equinox shouldn’t define the start of spring.
Instead, it could be seen to mark the season’s halfway point.
Dr Griffin says Chinese astronomers have the equinoxes and solstices as the centre of their seasons.
Thus their seasons begin and end on "cross-quarter days".
By this definition, spring in the southern hemisphere would begin around August 7-8 and continue until November 7-8.
"I do see the logic in the Chinese approach ... it would mean the middle of summer would be the longest day. I would be reasonably comfortable in the idea of spring starting on the cross-quarter and the equinox being the middle of spring.
"I don’t think there is a right or wrong to any of the dates. I think it is a scale of grey rather than black and white."
Gail Oates, a Taieri Mouth resident with a long-held interest in astronomy and astrology, is more adamant in her views: to define the start of spring by the start of the month is to deny scientific fact.
"Saying spring begins on September 1 is like stating the Earth is flat," she says.
"Summer solstice is the longest day; winter solstice is the shortest. And spring and autumn equinox are when the days and nights are equal. The seasonal changes should be observed on those occasions.
"Using the first of January for New Year is as random for us as the first of the ninth marking the beginning of spring. Likewise, December 1 for summer, March 1 for autumn and June 1 for winter.
"I think if we can get back to recognising the reasons for the seasons, and how we relate to the sun, we will have more connection with the environment. It’s a reminder that we are all part of nature, which is more powerful than humanity."
In pondering springtime, Dunedin Botanic Garden curator and team leader Alan Matchett looks not to the sky but to signs closer to hand.
"In some ways, spring is a subjective thing. It might be deemed to begin on September 1, but that doesn’t really mean much."
That said, he does think spring has arrived.
"We are seeing flowers you’d traditionally associate with spring start to bloom. The rhododendrons are starting to come into their own now ... The cold snap last week affected some plants in terms of their performance, although not their timing.
"We do get that equinox change that can bring the wind. And that can knock off blossoms. There is a row of flowering cherries on Arden St, near my office, which were in full flower last week. Well, after that storm, they lost a lot of the blossoms.
"In the world of plants, things can change from one week to another. We can get late frosts which affect a lot of plants, particularly when they are flowering.
"It is a vulnerable time of year."
Season of the eel
"The stars were just indicators that the season was coming, as opposed to being a demarcation of any sort.
"It wasn’t a case of looking at the stars and saying, ‘well, this constellation is there so it must be spring’. However, if certain stars were on the rise, they would then look for other signs in the natural world.
"Spring was defined by events such as when the kowhai bloomed, when the lamprey eels ran, when whitebait could be found.
"The word used in association with this period is kana, which is the Maori name for the lamprey eel. In some areas there is this term ‘koanga’, referring to a time of blossoming. There was definitely a term for summer, which was ‘raumati’; and, in the south, winter was ‘makariri’, which meant cold.
"As you can imagine, there was quite a marked difference in when events occurred. It depended on where you lived in this country. It can be quite confusing as things such as shellfish and birds can have different names in different areas."
Spring was typically a time for travel, Potiki says.
"As the big snow melt started, the pathways over to the West Coast would open; the weather was mild and they would have still had supplies.
"The big thing about spring — along with autumn — was harvest. It was time when there was an abundance of food. More food was gathered in autumn than in spring and food preservation techniques over winter allowed them to survive quite well.
"But there wasn’t a huge amount of food that was able to be stored through spring. That meant people could starve in summer. February was often the time of war."
In contrast, spring was often a time of peaceful cooperation.
"Different hapu and family would divide land up very clearly. You might have had a family on either side, working together ... but they’d stray on to someone else’s territory at their peril. Sometimes, these boundaries would be quite rudimentary, yet they were fiercely protected."
Potiki says although there was a shared understanding of how the seasons might work, the way this knowledge was articulated could differ from location to location.
"These localised bodies of knowledge evolved within a more generalised body of knowledge, yet were specific to certain areas.
"For instance, I grew up at Karitane, but it wasn’t until I was an adult that I comprehended how we used to act on natural signs, such as seagulls coming inland when a big southerly was on its way.
"That’s just one wee example, but if you take such knowledge and extend it over successive generations, package it up as a message to pass on, then those understandings and observations become more sophisticated."
