Sunshine

thetonynator · 21-06-2010 10:18pm #1

I was thinking today - ( no it didnt hurt!!) Today being the longest day of the year, with wall to wall sunshine, could a record for the longest hours of sunshine recorded in one day be broken?

I know that here, we lost a half an hours sunshine this evening when cloud covered the west, but some weather station somewhere surely had sunshine all day?

Mothman · 21-06-2010 10:45pm

It happened yesterday. Today's figures will be out at about 7.20 am (06z synops)
Casement 16.4hrs.

Certainly the highest daily value record in Republic for past 60 odd years and quite possibly in recorded history. Perhaps a northern station like Malin Head recorded longer in times pasat.

Deep Easterly · 22-06-2010 12:33am

Mothman wrote: »

It happened yesterday. Today's figures will be out at about 7.20 am (06z synops)
Casement 16.4hrs.

Certainly the highest daily value record in Republic for past 60 odd years and quite possibly in recorded history. Perhaps a northern station like Malin Head recorded longer in times pasat.

Maybe so, but 16.2hrs was Malin's top daily total within the 61-90 series at least.

http://www.met.ie/climate/malinhead.asp

while Casement tops (before today) was 15.8hrs.

Mothman · 22-06-2010 8:22am

21st June
Dublin Airport topped with 15.8 hours

Su Campu · 22-06-2010 9:05am

Mothman wrote: »

21st June
Dublin Airport topped with 15.8 hours

Really? There were one or two fog METARs there around lunchtime which I thought would have affected the sunshine, but there was unbroken sunshine at Casement. Strange how Dublin saw more. Maybe the weather station's location a couple of kilometers to the west of the observer meant it didn't actually get fog while further east did.

EDIT: Actually those METARs were for VCFG (Fog in the vicinity) so the airport didn't actually get any

EIDW 211500Z 14008KT 100V160 9000 VCFG FEW035 21/14 Q1021 NOSIG
EIDW 211430Z 13010KT 9999 VCFG FEW001 20/13 Q1021 NOSIG
EIDW 211400Z 12009KT 080V150 9000 VCFG FEW001 20/12 Q1022 NOSIG
EIDW 211330Z 12009KT 9000 VCFG FEW001 19/13 Q1022 NOSIG
EIDW 211300Z 12008KT 090V160 9999 VCFG FEW001 19/14 Q1022 NOSIG
EIDW 211230Z 12008KT 9999 VCFG FEW001 20/15 Q1022 NOSIG
EIDW 211200Z 11007KT 060V150 9999 VCFG FEW001 20/14 Q1022 NOSIG
EIDW 211130Z 10007KT 070V130 9000 VCFG FEW020 20/15 Q1022 NOSIG

Deep Easterly · 22-06-2010 7:29pm

Mothman wrote: »

21st June
Dublin Airport topped with 15.8 hours

Is daily sunshine total, like temperature and so forth, measured using the 0900hrs to 0900hrs rule? For example, is any sunshine recorded before 9am added on to the previous days total from 9am?

Mothman · 22-06-2010 7:38pm

Deep Easterly wrote: »

Is daily sunshine total, like temperature and so forth, measured using the 0900hrs to 0900hrs rule? For example, is any sunshine recorded before 9am added on to the previous days total from 9am?

No its 00-24h figure. as is the temperature data on Yesterday's Weather on Met.ie

Some climate stations do change cards at 09z, but the final total will be the 00-24h figure.

My climate station is 50m from my door and I change card after sunset, which means I can't have an early night at this time of year

Danno · 22-06-2010 7:54pm

LOL!!! Mothman, and for some of us, we only come to life when the sun goes down!

I miss those clear blue skies already.

Su Campu · 22-06-2010 9:52pm

Mothman wrote: »

No its 00-24h figure. as is the temperature data on Yesterday's Weather on Met.ie

Some climate stations do change cards at 09z, but the final total will be the 00-24h figure.

If a station changes a card at 09Z, how can they be sure some of the imprint isn't from that morning and not the day before? These mornings there could be nearly 5 hours of sunshine before the card is changed.

Mothman · 22-06-2010 10:05pm

Su Campu wrote: »

If a station changes a card at 09Z, how can they be sure some of the imprint isn't from that morning and not the day before? These mornings there could be nearly 5 hours of sunshine before the card is changed.

It is changed at 09z every morning, so the one card is only subjected to the pre 09z sunshine once.
The date and time of placement and removal are entered on the card so that the reader of the card knows the period that the card is in the recorder.

Su Campu · 22-06-2010 10:12pm

Mothman wrote: »

It is changed at 09z every morning, so the one card is only subjected to the pre 09z sunshine once.
The date and time of placement and removal are entered on the card so that the reader of the card knows the period that the card is in the recorder.

Ah OK, makes sense. Just another question, does rain affect the card. If it's showery weather, will sunshine be recorded immediately after the passing of a shower or is some of it lost in trying to burn through the wet card? (I haven't a clue what the cards are made of!)

Mothman · 22-06-2010 10:38pm

Su Campu wrote: »

Ah OK, makes sense. Just another question, does rain affect the card. If it's showery weather, will sunshine be recorded immediately after the passing of a shower or is some of it lost in trying to burn through the wet card? (I haven't a clue what the cards are made of!)

The Campbell Stokes recorder has many flaws, but continues to be used for continuity of record because it has been difficult to electronically replicate though there are recorders that do this.
Some of the issues.
Dew/frost on ball in morning. I bring ball into house during winter, not practical in Summer.
Birds doing business. Ball needs regular cleaning. Birds pulling the cards and tearing them to bits. This happened to me couple weeks ago but I replaced card before "losing" any sunshine.
Blobs of water on the ball after a shower can defract the burn and in winter (weaker sun)prevent the card being marked. I don't know how a damp card affects it but still likely to get scorched even if not burned through.
The human factor with the interpretation of the burn on the card. Not an issue with clear sky, but broken cloud and 2 readers of same card could differ by 10%

I've attached a photo of a recorder

Thomas828 · 27-06-2010 1:44pm

Well, we didn't get all day sunshine on the solstice in London. It started promisingly enough but by 3pm it had completely clouded over. Bummer!

owenc · 27-06-2010 1:56pm

Thomas828 wrote: »

Well, we didn't get all day sunshine on the solstice in London. It started promisingly enough but by 3pm it had completely clouded over. Bummer!

But its still bright so thats counted as sunlight hours.

thetonynator · 27-06-2010 8:11pm

owenc wrote: »

But its still bright so thats counted as sunlight hours.

Well I was talking about sunshine, not sunlight in my OP.

Guru Maith Agut · 02-07-2010 1:52am

Not trying to hijack here but a question for you in the know. . What time is first light at say for tomorrow? I dont mean sunrise, I mean first light.

Thank you in advance.

Joe Public · 02-07-2010 2:08am

Guru Maith Agut wrote: »

Not trying to hijack here but a question for you in the know. . What time is first light at say for tomorrow? I dont mean sunrise, I mean first light.

Thank you in advance.

If you're a smoker it's when you have your first fag in the morning.

Another definition is - when the center of the morning sun is 12° below the horizon.

Mothman · 02-07-2010 7:04am

Guru Maith Agut wrote: »

Not trying to hijack here but a question for you in the know. . What time is first light at say for tomorrow? I dont mean sunrise, I mean first light.

Thank you in advance.

How long is a peice of string?

If night is clear its not dark at all. If its cloudy, another matter...

To answer as I suspect you mean it...

The birds are starting about 4.15am and they may be a good indicater for first light.
Sunrise for my location is at 5.03am today

WolfeIRE · 02-07-2010 8:47am

Guru Maith Agut wrote: »

Not trying to hijack here but a question for you in the know. . What time is first light at say for tomorrow? I dont mean sunrise, I mean first light.

Thank you in advance.

is there not a 15-20 min difference between first light on East Coast and first light on West Coast? keep that in mind.

owenc · 02-07-2010 8:52am

Guru Maith Agut wrote: »

Not trying to hijack here but a question for you in the know. . What time is first light at say for tomorrow? I dont mean sunrise, I mean first light.

Thank you in advance.

About 3.40 am.

owenc · 02-07-2010 8:53am

Mothman wrote: »

How long is a peice of string?

If night is clear its not dark at all. If its cloudy, another matter...

To answer as I suspect you mean it...

The birds are starting about 4.15am and they may be a good indicater for first light.
Sunrise for my location is at 5.03am today

The sun rises at 4.40 its going to be brighter wayy before 4.15 i'd say 3.40/50 plus it doesn't even get dark here we have nautical twilight all night. Heres a sunshine calculator http://akweathercams.faa.gov/srsscalc.php

Mothman · 02-07-2010 2:12pm

owenc wrote: »

The sun rises at 4.40 its going to be brighter wayy before 4.15 i'd say 3.40/50 plus it doesn't even get dark here we have nautical twilight all night. Heres a sunshine calculator http://akweathercams.faa.gov/srsscalc.php

Time of sunrise is down to location, the only location we have to go on is "Home"

Westport 5.12am
Ashford Co. Wicklow 5.03am
Cork 5.19
Coleraine 4.52

As for first light, entirely a question of interpretation

DOCARCH · 02-07-2010 3:20pm

Mothman wrote: »

Time of sunrise is down to location, the only location we have to go on is "Home"
Westport 5.12am
Ashford Co. Wicklow 5.03am
Cork 5.19
Coleraine 4.52

As for first light, entirely a question of interpretation

Is first light not defined? I thought first light was reached/calculated when the sun is something like 10 degress below the horizon, so first light is usually approx. half an hour before sunrise in these parts?

owenc · 02-07-2010 4:02pm

DOCARCH wrote: »

Is first light not defined? I thought first light was reached/calculated when the sun is something like 10 degress below the horizon, so first light is usually approx. half an hour before sunrise in these parts?

The sun doesn't go below 10 degrees in the summer. It is twilight all night. Cival twilight would be the first light as that is when the sun is just below the horizon, which means its basically bright.

DOCARCH · 02-07-2010 4:11pm

What I was trying to say is that first light can be given a precise time, by definition, for a specific location obvioulsy along with a precise time for sunrise.

I'm not sure if Mothman was saying that first light is undefined or open to interpretation?

Mothman · 02-07-2010 4:21pm

DOCARCH wrote: »

I'm not sure if Mothman was saying that first light is undefined or open to interpretation?

Yes Doc you are correct but my interpretation of the original question was not referring to this.

First Light is often refered to as the beginnning of nautical twilight which is when the sun is 12° below horizon. Currently at my site this is at 2.47am.

owenc · 02-07-2010 4:23pm

Mothman wrote: »

Yes Doc you are correct but my interpretation of the original question was not referring to this.

First Light is often refered to as the beginnning of nautical twilight which is when the sun is 12° below horizon. Currently at my site this is at 2.47am.

What happens if you have nautical twilight all night? As i don't call that light, its bright enough to read a book or to walk but not bright bright.

Sunshine

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