Re: [Phys-L] definition of spring

[Larry Smith <larry.smith@snow.edu>]

Apparently there are various definitions (astronomical, meteorological, etc.). 

My colleague thinks the definition of spring hinges on the definition of winter which he would like to define in terms of daylight or temperature: the 91 shortest days or the 91 consecutive coldest days on average. Neither of these allow for spring to start as late as March 21 in the northern hemisphere. He thinks it makes more sense to have the vernal equinox be the middle of spring. While definitions are somewhat arbitrary, why do astronomers say spring _starts_ on the vernal equinox?

Larry




> On Mar 23, 2021, at 5:39 PM, Anthony Lapinski <alapinski@pds.org> wrote:
>
> I think you meant March 21.
>
> And also ...over the equator at noon.
>
> Interestingly, the equator is the only location that gets 12 hours of
> daylight every day of year. My astronomy students every year find this
> difficult to understand/explain.
>
> On Tue, Mar 23, 2021 at 7:22 PM Brian Whatcott <betwys1@sbcglobal.net>
> wrote:
>
> >  Astronomical Spring in the northern hemisphere is the vernal equinox -
> > when the sun is directly over the equator.
> > Meteorological Spring is counted as the three months following March 1st.
> >    On Monday, March 22, 2021, 06:18:40 PM CDT, Larry Smith <
> > larry.smith@snow.edu> wrote:
> >
> > What is the definition of spring (the season) and why?
> >
> > Thanks,
> > Larry
> >
> > _______________________________________________
> > Forum for Physics Educators
> > Phys-l@mail.phys-l.org
> > https://www.phys-l.org/mailman/listinfo/phys-l
> >
> > _______________________________________________
> > Forum for Physics Educators
> > Phys-l@mail.phys-l.org
> > https://www.phys-l.org/mailman/listinfo/phys-l
>
> -- 
>
>
> <http://www.pds.org>
> <https://www.facebook.com/princetondayschool> 
> <https://twitter.com/PDSPanthers> 
> <https://www.youtube.com/channel/UCVE-nTva0BlK0rT6vayqpIQ> 
> <https://www.instagram.com/princetondayschool/>
>
>
> *CONFIDENTIALITY NOTE:* 
> The information transmitted, including attachments, is intended only for 
> the person(s) or entity to which it is addressed and may contain 
> confidential and/or privileged material. Any review, retransmission, 
> dissemination or other use of, or taking of any action in reliance upon 
> this information by persons or entities other than the intended recipient 
> is prohibited. If you received this in error, please contact the sender and 
> destroy any copies of this information.
>
>
>
>
> Please consider the environment 
> before printing this email.
>
>
>
> _______________________________________________
> Forum for Physics Educators
> Phys-l@mail.phys-l.org
> https://www.phys-l.org/mailman/listinfo/phys-l