latitude, light hours duration... and strange observation

[pirataloko]

I hope i'm not the only one that perceived this, but i didn't find another topic in the forum, so please if some moderator consider there is another thread about this subject, merge with this one.

I live in Spain, located in Northern Hemisphere, in December 21Th the winter begins and is the day with the lagest night. Nothing new in this point. The night arrives where i live between 17:20 - 18:00 (more o r less) for a long time (probably until March) obviously these observations are the ones i can see every year. But not this year

But i noticed mid January that at 18:30 day light was perfectly visible when in this date usually at 18:00 (probably long before) the night is totally seated, two days ago i commented this with some students, and we saw that at 18:50 the sun light could be seen on the horizon. I think this is a relevant sign and i'm really interested in know about it. The only thing i can relate to this was the new about Greenland early dawn this year ( two days before).

But even more amazing that this phenomenon, is the fact that a great amount of people is not aware of this, and who is aware has a reaction really strange with no interest in knowing the reason for this.

My initial thought is that it can be related to the pole shifting and the latitude may be changing, that could be an explanation to these "extra light" hours. I only wanted to share this and to encourage you to see this phenomenon, and a feedback about this subject may be interesting to compile data about the light hours in different locations it could tell us about the way these changes are happening.

 

[mkrnhr]

Hi Pirataloko,
Most of the time, the perceived light after sunset depends upon the atmospheric conditions, so maybe there is a link. Could you give an approximative time for the disappearance of the daylight?

 

[pirataloko]

Hi Pirataloko,
Most of the time, the perceived light after sunset depends upon the atmospheric conditions, so maybe there is a link. Could you give an approximative time for the disappearance of the daylight?

Since my view in a city ( buildings, Thursday 3 Th, at 18:50 pm i observed the lastest light of the sun in the day in this city. And it isn't a sunset..... normally (years before) at 18:00 more or less the sunsent had hapenned totally (in this case at 18:50 it was dark night) and now (this year) at 18:50 i can see the lastest lights. At 17:00 pm i observed the sun the same Thursday and it was quite higher than expected in the sky for this time in the year.

Today i arrived to my friend's house few minutes before 19:00 and i'd seen the last rays of light, or daylight, i think i'm aware of this since mid January, i use to work in the evenings in the hour that the sunsent happens and i leave a window to see everyday the time that the sun goes, and this year it's happening at 18:50 or later and it's not "the usual" in this days of the year, a diferent thing as i interpreted what i observed: is the sunset and how can affect the atmosferic circunstances to it.

 

[mkrnhr]

Hello Pirataloko,

Here i gathered for you some data for the Sun rising and setting from three locations in Spain this week in Local Time. You can choose the closest city as a reference.

Location
Name Spain, Barcelona
Coordinates 002° 09' 00" E 41° 21' 00" N
03/02/2011
Dawn 06:27 / 06:59 / 07:32
Sunrise 08:01
Sunset 18:10
Dusk 18:39 / 19:12 / 19:44
04/02/2011
Dawn 06:26 / 06:58 / 07:31
Sunrise 08:00
Sunset 18:11
Dusk 18:40 / 19:13 / 19:45
05/02/2011
Dawn 06:25 / 06:57 / 07:30
Sunrise 07:59
Sunset 18:12
Dusk 18:41 / 19:14 / 19:46
06/02/2011
Dawn 06:24 / 06:56 / 07:29
Sunrise 07:58
Sunset 18:13
Dusk 18:42 / 19:15 / 19:48
07/02/2011
Dawn 06:23 / 06:55 / 07:28
Sunrise 07:57
Sunset 18:15
Dusk 18:44 / 19:16 / 19:49
08/02/2011
Dawn 06:22 / 06:54 / 07:27
Sunrise 07:56
Sunset 18:16
Dusk 18:45 / 19:18 / 19:50
09/02/2011
Dawn 06:21 / 06:53 / 07:26
Sunrise 07:55
Sunset 18:17
Dusk 18:46 / 19:19 / 19:51

Location
Name Spain, Madrid
Coordinates 003° 41' 00" W 40° 26' 00" N
03/02/2011
Dawn 06:50 / 07:21 / 07:54
Sunrise 08:23
Sunset 18:35
Dusk 19:04 / 19:36 / 20:08
04/02/2011
Dawn 06:49 / 07:21 / 07:53
Sunrise 08:22
Sunset 18:36
Dusk 19:05 / 19:37 / 20:09
05/02/2011
Dawn 06:48 / 07:20 / 07:52
Sunrise 08:21
Sunset 18:37
Dusk 19:06 / 19:38 / 20:10
06/02/2011
Dawn 06:47 / 07:19 / 07:51
Sunrise 08:20
Sunset 18:39
Dusk 19:07 / 19:39 / 20:11
07/02/2011
Dawn 06:46 / 07:18 / 07:50
Sunrise 08:18
Sunset 18:40
Dusk 19:08 / 19:41 / 20:12
08/02/2011
Dawn 06:45 / 07:17 / 07:49
Sunrise 08:17
Sunset 18:41
Dusk 19:09 / 19:42 / 20:13
09/02/2011
Dawn 06:44 / 07:16 / 07:48
Sunrise 08:16
Sunset 18:42
Dusk 19:11 / 19:43 / 20:15

Location
Name Spain, La Coruna
Coordinates 008° 24' 00" W 43° 22' 00" N
03/02/2011
Dawn 07:10 / 07:44 / 08:18
Sunrise 08:48
Sunset 18:48
Dusk 19:18 / 19:52 / 20:25
04/02/2011
Dawn 07:09 / 07:43 / 08:17
Sunrise 08:47
Sunset 18:49
Dusk 19:19 / 19:53 / 20:26
05/02/2011
Dawn 07:08 / 07:42 / 08:15
Sunrise 08:45
Sunset 18:50
Dusk 19:20 / 19:54 / 20:28
06/02/2011
Dawn 07:07 / 07:40 / 08:14
Sunrise 08:44
Sunset 18:52
Dusk 19:22 / 19:55 / 20:29
07/02/2011
Dawn 07:06 / 07:39 / 08:13
Sunrise 08:43
Sunset 18:53
Dusk 19:23 / 19:57 / 20:30
08/02/2011
Dawn 07:05 / 07:38 / 08:12
Sunrise 08:42
Sunset 18:54
Dusk 19:24 / 19:58 / 20:31
09/02/2011
Dawn 07:04 / 07:37 / 08:11
Sunrise 08:41
Sunset 18:56
Dusk 19:25 / 19:59 / 20:32

Here are the conventional definition i took from _http://www.usno.navy.mil/USNO/astronomical-applications/astronomical-information-center/rise-set-twi-defs

Sunrise and sunset conventionally refer to the times when the upper edge of the disk of the Sun is on the horizon, considered unobstructed relative to the location of interest. Atmospheric conditions are assumed to be average, and the location is in a level region on the Earth's surface.

Sunset it the easiest to observe. If you have a clear horizon you can note the time (approximatively) at which the Sun sets down and compare it to the above chart.

Twilight: Before sunrise and again after sunset there are intervals of time, twilight, during which there is natural light provided by the upper atmosphere, which does receive direct sunlight and reflects part of it toward the Earth's surface. Some outdoor activities may be conducted without artificial illumination during these intervals, and it is useful to have some means to set limits beyond which a certain activity should be assisted by artificial lighting. The major determinants of the amount of natural light during twilight are the state of the atmosphere generally and local weather conditions in particular. Atmospheric conditions are best determined at the actual time and place of events. Nevertheless, it is possible to establish useful, though necessarily approximate, limits applicable to large classes of activities by considering only the position of the Sun below the local horizon. Reasonable and convenient definitions have evolved.

Of course, the amount of light after Sunset when it comes to visual observation is a little subjective. It depends upon the atmospheric conditions (clouds on the horizon etc.), the local horizon, and also on the eyes of the observer :) so it is better to oberve the Sunset (or the Sunrise) to reduce the error.

Anyway, here are the different definitions of twilight from the same page:

Civil twilight is defined to begin in the morning, and to end in the evening when the center of the Sun is geometrically 6 degrees below the horizon. This is the limit at which twilight illumination is sufficient, under good weather conditions, for terrestrial objects to be clearly distinguished; at the beginning of morning civil twilight, or end of evening civil twilight, the horizon is clearly defined and the brightest stars are visible under good atmospheric conditions in the absence of moonlight or other illumination. In the morning before the beginning of civil twilight and in the evening after the end of civil twilight, artificial illumination is normally required to carry on ordinary outdoor activities. Complete darkness, however, ends sometime prior to the beginning of morning civil twilight and begins sometime after the end of evening civil twilight.

Nautical twilight is defined to begin in the morning, and to end in the evening, when the center of the sun is geometrically 12 degrees below the horizon. At the beginning or end of nautical twilight, under good atmospheric conditions and in the absence of other illumination, general outlines of ground objects may be distinguishable, but detailed outdoor operations are not possible, and the horizon is indistinct.

Astronomical twilight is defined to begin in the morning, and to end in the evening when the center of the Sun is geometrically 18 degrees below the horizon. Before the beginning of astronomical twilight in the morning and after the end of astronomical twilight in the evening the Sun does not contribute to sky illumination; for a considerable interval after the beginning of morning twilight and before the end of evening twilight, sky illumination is so faint that it is practically imperceptible.

So it's better to use the Sunset as a reference.

Edit: quotes

 

[pirataloko]

Well mkrnhr, i guess we're not speaking about the same subject. I'll try one more time (and sorry for my explanations in english, that may be is the problem here).

First of all i agree with the information about the sunset you put in the previous messagge. But this isn't the point.

I'm observing this everyday. My question is related to the hour that this phenomenon happened the years before 2011. I think there is a difference and now the sunset happens after the hour it happened in other years.. so the point is the hour it's happening this year versus the time it was happening in previous years. I know i can find information in the internet, in only asked if someone else in another location has the impression that this year is happening at a different time that in previous years.

A student that lives in the country told me that people there are seeing the light longer than other years too, and this have been commented.

As an example , when i was in University at 18:00 "The Simpsons" were emitted from monday to friday, and at 18:00 in winter months it was dark/closed night (for a great amount of days), this observation related with my observation in mid january (that at 18:30 the sun light was seen only 3 weeks after the winter equinox) makes me think that some change has happenned or is happening. That's all. I hope i can be undesrtood.

 

[Laurentien2]

I know i can find information in the internet, in only asked if someone else in another location has the impression that this year is happening at a different time that in previous years.

I understand you pirataloko and checked last year 2010 chart for sunrise and sunset for Barcelona Spain and they are the same for February 2010 and 2011. You can easily find the information on the net.

 

[pirataloko]

I understand you pirataloko and checked last year 2010 chart for sunrise and sunset for Barcelona Spain and they are the same for February 2010 and 2011. You can easily find the information on the net.

Ok thank you. I guess i have to think why am i having this strange sensation? it seems strange ;D

 

[mkrnhr]

I think there is a difference and now the sunset happens after the hour

Don't worry about the English, we are all trying :)
I forgot to tell you that the chart i sent you was made by an old software that has like ten years old. So if something changed this year, you will see a difference between the chart (what was expected ten year ago for the hour of sunset) and reality (what you see, the hour of sunset).
It is good to compare our perception to something because how we see lights in the city and darkness is sometimes subjective :)

mod fixed quotes

 

[Nević Nenad]

I understand you pirataloko and checked last year 2010 chart for sunrise and sunset for Barcelona Spain and they are the same for February 2010 and 2011. You can easily find the information on the net.

Ok thank you. I guess i have to think why am i having this strange sensation? it seems strange ;D

You are not alone. I'm also seeing that strange times of sunsets, but I am not in Spain, and it goes some 4-5 years in the past, not just last two years or so. Also I have noticed different times of dawn, and what is the most interesting to me, somehow angle of Sun looks different, more to the southern horizont. But maybe all of that can be explained with changes in the atmosphere. Light is behaving differently in different atmosphere.

Do you remember comet 17P/Holmes, from 2007?

http://www.sott.net/articles/show/142415-Sudden-Naked-Eye-Comet-Shocks-the-Astronomy-World

It was first time seen in the October, but I'm still convinced that my brother and I saw it in September, exactly one month before her "official appearance". Whole that month we were watching it, trying to find what is that, showing people but no one was interested, until "big" news. But we was watching it whole month before that. I don't know how it is possible, but I'm pretty sure in what I was seeing (the same thing on the sky as like it was officially one month later).

So, I'm even stranger :P

 

[Laura]

I think that, perhaps. members of this forum are being sensitized to observe our world more closely. And, perhaps, not having done so very much in years past, along with some anxieties created by rumors, may think they are seeing things that are actually quite normal.

I was sitting downstairs yesterday and the winter sun was shining brightly in the salon and I thought "hmmm... just a month or so ago it was getting dark at 4/30 or 5 p.m. and now it is after six and the sun is still shining!" Well, I'm not sure about the getting dark times, that was just what it felt like to me at the time.

This morning, there are a lot of birds chirping like it was spring and it is something like 0 degrees C outside. So, I wonder: "why are those birds chirping like it is spring?"

Anyway, I think it is useful to have a calendar that gives the times of sunrise and sunset and to keep track of those things by observing them. Also, the phases of the moon. We should be in touch with our environment, but let's just observe for awhile and get used to it!

 

[rrraven]

I think it is useful to have a calendar that gives the times of sunrise and sunset and to keep track of those things by observing them. Also, the phases of the moon. We should be in touch with our environment, but let's just observe for awhile and get used to it!

lets observe and record...dry erase white board markers work well on windows...find a window (one you haven't taped up with alu foil yet,lol)with a view of the sun or moon and start to mark the position and time and date like your personal stonehenge :)

there is a old farmers almanach site on FB

Founded:
1792
About:
The Original Farmer's Almanac. "Useful with a pleasant degree of humor." Now in our 219th year! The 2011 edition can be found in local bookstores, on newsstands, or online at Almanac.com/Store. To order by phone or for questions, call 1-800-256-2622.

maybe handy to have around

 

[clerck de bonk]

I think that, perhaps. members of this forum are being sensitized to observe our world more closely. And, perhaps, not having done so very much in years past, along with some anxieties created by rumors, may think they are seeing things that are actually quite normal.

that's what I thought until I read this...

This morning, there are a lot of birds chirping like it was spring and it is something like 0 degrees C outside. So, I wonder: "why are those birds chirping like it is spring?"

Same wonderings(for a week now), same conditions(about) here too. So what You might say.
It's just that You live in southern France(correct?) and I live in southern Finland...

Anyway, I think it is useful to have a calendar that gives the times of sunrise and sunset and to keep track of those things by observing them. Also, the phases of the moon. We should be in touch with our environment, but let's just observe for awhile and get used to it!

Second that :)