False Spring

[Philip Veerman <>]

Thanks for that Martin………. It could reasonably be argued that defining the start of spring by the equinox date reduces the aspect that the season is a transition. If the start of spring is 21 September, it is less of a transition, because the fundamental change in day length has already happened.

 

From: Martin Butterfield [ Sent: Sunday, 2 September, 2018 12:19 PM          To: Mark Clayton; COG List            Subject: Re: [canberrabirds] False Spring

 

Mark

 

The definition of seasons is very much a matter of choice, like everything else to do with classifications.  However in the same way that Birdlife Australia are the official definers of bird taxonomy in Australia, the official definition of seasons must come from the Bureau of Meteorology who say:

Seasons

In Australia, the seasons are defined by grouping the calendar months in the following way:

·         Spring - the three transition months September, October and November.

·         Summer - the three hottest months December, January and February.

·         Autumn - the transition months March, April and May.

·         Winter - the three coldest months June, July and August.

These definitions reflect the lag in heating and cooling as the sun appears to move southward and northward across the equator. They are also useful for compiling and presenting climate-based statistics on time scales such as months and seasons.

The use of the equinox as defining seasons is a hang-over from the Old Dart.

 

Martin

Martin Butterfield

http://franmart.blogspot.com.au/

 

On Sun, 2 Sep 2018 at 11:05, Mark Clayton <> wrote:

Geoffrey,

He still has until September 23 to get his tail right. That is the official start of spring, not September 1 like everyone thinks.

Mark

 

On 2/09/2018 10:01 AM, Geoffrey Dabb wrote:

 

 

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