Winter solstice

Aussie2005 · Unread post by **Aussie2005** » Wed 21/06/2006 21:12

Thursday 22/6/06 00:23 hrs in New Zealand, Wednesday 22:23 here in Oz, summer just about on its way

Flutterbye · Unread post by **Flutterbye** » Wed 21/06/2006 21:22

Just a tad optimistic at this stage

Gary Roberts · Unread post by **Gary Roberts** » Wed 21/06/2006 21:25

Flutterbye wrote:Just a tad optimistic at this stage

Nah, I can even feel the tan...!

Flutterbye · Unread post by **Flutterbye** » Wed 21/06/2006 21:26

Gary Roberts wrote:
Flutterbye wrote:Just a tad optimistic at this stage
Nah, I can even feel the tan...!

Yeah right

Willoughby · Unread post by **Willoughby** » Wed 21/06/2006 21:29

Aussie2005 wrote:...summer just about on its way

Can see the convection spirialing up right before my eyes

NZ Thunderstorm Soc · Wed 21/06/2006 21:45

...tonight is going to be a long night

possbly the longest night of the year?

JohnGaul
NZTS

Flutterbye · Unread post by **Flutterbye** » Wed 21/06/2006 21:48

NZ Thunderstorm Soc wrote:...tonight is going to be a long night
possbly the longest night of the year?

JohnGaul
NZTS

I don't know about the longest but it feels like the coldest.

Aussie2005 · Unread post by **Aussie2005** » Wed 21/06/2006 22:06

Flutterbye wrote:Just a tad optimistic at this stage

With a max of 17.9Â° today even the weather thinks summer is on the way. Pity that weather has a bad memory !

Flutterbye · Unread post by **Flutterbye** » Wed 21/06/2006 22:08

Aussie2005 wrote:
Flutterbye wrote:Just a tad optimistic at this stage
With a max of 17.9Â° today even the weather thinks summer is on the way. Pity that weather has a bad memory !

I still have spring flowers blooming in the face of the cold - strange

Willoughby · Unread post by **Willoughby** » Wed 21/06/2006 22:24

Flutterbye wrote:
Aussie2005 wrote: With a max of 17.9Â° today even the weather thinks summer is on the way. Pity that weather has a bad memory !
I still have spring flowers blooming in the face of the cold - strange

Are you sure? I remember you saying you have Daffodils springing in May I think it was.. we have ones that look like daffodils that have sprung already.. might be those ones? By the look of the trees and flowers around here.. I think it's going to be a long hard winter.

Flutterbye · Unread post by **Flutterbye** » Wed 21/06/2006 22:37

Foggy Hamilton wrote:
Flutterbye wrote: I still have spring flowers blooming in the face of the cold - strange
Are you sure? I remember you saying you have Daffodils springing in May I think it was.. we have ones that look like daffodils that have sprung already.. might be those ones? By the look of the trees and flowers around here.. I think it's going to be a long hard winter.

The first lot that bloomed in May are still out and the rest have followed suit. Amazing - might be that the cold is preserving them. Must get a picture tomorrow.

Willoughby · Unread post by **Willoughby** » Wed 21/06/2006 22:43

You guys got a very warm May didn't you? if things calm down there.. it should again become warmer than normal with those sea temps still looking very warm right around from Fjordland to Timaru

Flutterbye · Unread post by **Flutterbye** » Wed 21/06/2006 22:46

Foggy Hamilton wrote:You guys got a very warm May didn't you? if things calm down there.. it should again become warmer that normal with those sea temps still looking very warm right around from Fjordland right around to Timaru

I think we did but I know April was warm - all seems so long ago

Storm Struck · Unread post by **Storm Struck** » Wed 21/06/2006 22:52

I thought the shortest day was today going by calendars etc

.
It's like when Karren said the shortest day tomorrow and I thought no hang on that was today.
so what day is it then

.
Cheers
Jason.

NZ Thunderstorm Soc · Wed 21/06/2006 22:58

Jasestrm wrote:I thought the shortest day was today going by calendars etc .
It's like when Karren said the shortest day tomorrow and I thought no hang on that was today.
so what day is it then .
Cheers
Jason.

There IS no shortest day, it's the longest night, that's the issue
21 and 22 should be equal lenght?

JohnGaul
NZTS

Aussie2005 · Unread post by **Aussie2005** » Wed 21/06/2006 23:54

There IS no shortest day, it's the longest night, that's the issue
21 and 22 should be equal lenght?

JohnGaul
NZTS[/quote]

I do not have a scientific background but I would think that the length of day on the 21st and 22nd will / can vary even if the difference is only minor as the time when solstice occurs varies as seen in the following ...
06-21-2005 06:36 UTC
06-21-2006 12:23 UTC
06-21-2007 18:11 UTC
06-21-2008 00:00 UTC

Just to complicate things a bit more I found this article ..

The longest day is longer than the longest night, and the shortest day is longer than the shortest night, for the reason that sunrise occurs when the upper edge of the disk of the Sun appears on the horizon, and sunset is at the moment when the upper edge disappears below the horizon. These are the instants of first and last direct sunlight; but at these times the center of the Sun's disk is still 50 minutes of arc vertically below the horizon, because the semidiameter of the sun is 16 minutes of arc, and in addition the Sun is seen 34 minutes of arc above its actual geometric position on account of atmospheric refraction. Consequently, the length of every day exceeds the time that the center of the Sun is geometrically above the horizon by the intervals of time required for the Sun to move through these extra amounts of 50 minutes of arc in altitude at both rising and setting, or 100 minutes of arc altogether; this shortens the night by the same amount.
On any two dates when the center of the Sun is at equal distances north and south of the equator, as it is at the summer and winter solstices, the center is geometrically below the horizon on one date for the same length of time as it is above the horizon on the other date; but on both dates the upper edge of the disk is visible longer than the center is geometrically above the horizon by the time required for 100 minutes of arc of motion in altitude, and therefore the day that is the longer exceeds the night on the other date by twice this amount, i.e., by the time equivalent of 200 minutes of arc in altitude. This excess is greater the higher the latitude because the path of the Sun at rising and setting is at a smaller angle with the horizon, and more time is required in this slanting motion to cover a given vertical distance.

Latitude .. Longest Day .. Longest Night .. Shortest Day Shortest Night .. Excess of Day over Night

25Â° N .. 13h 42m .. 13h 25m .. 10h 35m ..
10h 18m .. 17m
35Â° N .. 14h 31m .. 14h 12m .. 9h 48m ..
9h 29m .. 19m
40Â° N .. 15h 02m .. 14h 40m .. 9h 20m ..
8h 58m .. 22m
45Â° N .. 15h 38m .. 15h 14m .. 8h 46m ..
8h 22m .. 24m
50Â° N .. 16h 23m .. 15h 56m .. 8h 04m ..
7h 37m .. 27m
60Â° N .. 18h 53m .. 18h 08m .. 5h 52m ..
5h 07m .. 45m

Michael · Unread post by **Michael** » Thu 22/06/2006 10:00

I think its taken at 00 UTC or something ie the sun is at 5.57 RA and 23.26.14 N 21st and 23.26.17 today at 6.01RA

Gary Roberts · Unread post by **Gary Roberts** » Thu 22/06/2006 10:19

http://en.wikipedia.org/wiki/Solstice

squid · Unread post by **squid** » Thu 22/06/2006 11:26

yay summer ijs on its way now that the shortest day os over and done with

Michael · Unread post by **Michael** » Thu 22/06/2006 13:07

Didnt you want winter and rain

squid wrote:yay summer ijs on its way now that the shortest day os over and done with

squid · Unread post by **squid** » Thu 22/06/2006 14:18

na summer and rain hate winter

Manukau heads obs · Thu 22/06/2006 15:49

and to complicate things
the earliest the sun sets and the latest the sun rises for winter, and the opposite for summer occur about 10 days or so either side of the shortest/longest day....look up a table of tide/sun/moon times and you will see what i mean

RWood · Unread post by **RWood** » Thu 22/06/2006 16:00

Yes, because of the variable length of the "actual solar day" (length between successive sun zenith transits) - resulting in in the midpoint of the day varying between about 11.43 and 12.13 in UT/GMT terms. The midpoint is getting later between an April date and one past midwinter, hence the earliset sunset here is a bit before solstice and the latest sunrise a little after it. In December the midpoint advances quite rapidly and so the earliest sunrise is earlyish December etc. Of course in lower latitudes where daylength varies less the effect is more pronounced. To see the pure effect, look at sunrise/sunset tables for an equatorial location.

Gary Roberts · Unread post by **Gary Roberts** » Thu 22/06/2006 16:33

http://en.wikipedia.org/wiki/Solstice

Just in case you missed it the first time.

squid · Unread post by **squid** » Thu 22/06/2006 20:15

oh my small brain too much for it

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