Do skies get better in winter?

[evilgeenius]

Hi

Do the skies get better in Winter? I know we get more dark hours, but apart from that is the actual seeing better? Why is this?

Cheers

[spidan]

The surface of the planet is colder so less heat is radiated back up during the night.

[Nova]

the colder tempratures will provide better seeing. During the warmer months as the surface of the planet cools at night and the heat "haze" can make objects appear to wobble. To me it sometimes looks as if water is running over my fov. As there is less heat during the winter months this effect is reduced

[RikM]

The skies are darker in winter so you have better contrast for DSO's against the background sky. If you observe from in town though, you can have thermal plumes from poorly insulated houses messing up the local seeing though, so it's not all good.

[umadog]

Seeing and transparency: Seeing and Transparency in Astronomy Defined for the Beginner

Transparency is better in the winter when there is less water vapour, pollen, etc, in the skies. Where I am, transparency accounts for about a 1.5 magnitude limiting difference between winter and summer. Some of the best seeing, on the other hand, occurs on those muggy still days with no wind and air-motion. So it's quite possible to have poor transparency and good seeing (as well as the inverse).

[MorningMajor]

Well, they can't get any worse can they!

Seriously though, what you also get in winter is more opportunity - how many clear evenings have we had in summer which slowly cloud over to be useless by the time it's dark - if it's clear a 6pm in December get out there!

[Neilius]

In winter you have a relatavely normal sleeping pattern, whereas in summer you are practically a walking zombie by September!

There is generally more to see in winter skies too

[ronin]

The sun is at a lower angle = less intense.

Less sunlight = less heating.

Less heating = less evaporation off the Atlantic.

Less evaporation = less cloud

Less cloud = clearer nights.

We have in general a West to East weather so the Atlantic is very relevant.

If the weather comes from the East then there is a lot less water so again less cloud and clearer nights.

Cannot recall what happens with the jet stream but that also is highly relevant. Worth looking up as I recall.

One hiccup is that the gulf stream will show hysteresis so there will be a lag in the ocean temperature compared to the atmosphere temperature, so I would expect the "heating/evaporation" to last a bit longer after the summer solstice then it effect before.

[hemihaggis]

Seriously ...?

[Vali x]

that...i didnt knew ! now i do...thanks

[russ]

There is a common misconception that winter nights are better. But it's simply not the case. Transparency should be better but the last two winters have been dreadful, with highly muted skies. The transparency simply hasn't been very good at all.

While people automatically think that winter will produce better seeing but it's actually the reverse. The summer provides, normally, the better seeing.

Things are well messed up with our climate, just not as it should be. I personally am not wishing anything away because last Autumn/Winter was 6 months of misery.

[shaunster]

Russ speaks the truth.

The sun is at a lower angle = less intense.

Less sunlight = less heating.

Less heating = less evaporation off the Atlantic.

Less evaporation = less cloud

Less cloud = clearer nights.

We have in general a West to East weather so the Atlantic is very relevant.

If the weather comes from the East then there is a lot less water so again less cloud and clearer nights.

Cannot recall what happens with the jet stream but that also is highly relevant. Worth looking up as I recall.

One hiccup is that the gulf stream will show hysteresis so there will be a lag in the ocean temperature compared to the atmosphere temperature, so I would expect the "heating/evaporation" to last a bit longer after the summer solstice then it effect before.

Nice theory, not true but interesting anyway

[brantuk]

It does get darker though, and earlier. So stuff's easier to see, and you do get more chance to go outside with the gear.

But it is true that winter's not what it used to be

[evilgeenius]

russ, what is the explanation as to why the summer nights are better? just that they have been better recently?

So opinion is divided. Why would this be? Surely people are giving these answers from experience?

WHAT IS THE TRUTH!?

Is it simply that we get more hours of darkness in winter, therefore there is more oppurtunity for clear skies? Or do a lot of people not go out in summer because it get's dark quite late?

Clear Winter/Summer Skies!

[rwilkey]

Personally speaking, I think Winters are better for the longer nights and I also prefer the Winter constellations including Taurus and Orion, of course, my favourites

[todd8137]

i had a great night last night, M31, which was dim,, m13 that was mega its a great glob cluster not my fav but all the same the 10mm uwa gave me a mega look and was twinkleing ,m92 some say not as good but i love this one as well,m57 as normal,cassiopeia,cygnus saggita, spoilt for choice last night saturn and mars if you have a clear path to them commets theres lots out there they was easy with the 12"dob

the 90mm frac was fair game as well i can see most if not all with albeit smaller and brighter

winter as its pros and cons good seeeing yes frost cold hands ,coffee going cold to quick frosty telescopes blah blah enjoy these warm nights

pat

[laser_jock99]

The clearest conditions can occur when the air mass changes from low to high pressure or the even other way round. There is frequently a window of clear transparent air between weather systems that may only last a few hours. It can also be windy during these changes which doesn't help the 'seeing'. But if it's transparency you're after then keep an eye on the forecast and learn when to expect these brief spells of optimum weather.

[Rob]

To be fair its a mixed bag in the UK.. BUT, and its a big but I grant you. You can be blessed with some gob smacking skies from time to time. I usually grab a good handful in the summer time, late I grant you. November can be iffy.. but December & January (my fave month) can pay dividends I can tell ya!.

Hang in there.. this is astronomy, rough n smooth. But when its smooth.. its just fantastic

[geoff_k]

I think Russ is right. Recent winters expecially the last one have not been particularly good.

You obviously get more 'darkness' as it were, but that just seems to mean more time to be disappointed.

Perhaps the upcoming winter will prove me wrong but I wouldn't count on it.

[russ]

Perhaps the upcoming winter will prove me wrong but I wouldn't count on it.

Lets hope so. At the moment cold crystal clear winter nights of old are becoming things of myth and legend.

russ, what is the explanation as to why the summer nights are better? just that they have been better recently?

Winter nights should be the more transparent. A mass of twinkling stars on a velvet black background from a dark site. But the last few winters just haven't delivered on the promise. Highly turbulent air with murky washed out skies. Not as winter skies should be.

Summer skies are better for planetary viewing believe it or not. They produce the more steady seeing needed for good planetary views.

I enjoy the skies all year round. There simply isn't a boring sky. But if pressed, my favourite period is just starting now. Late July through too September. All my all time favourite objects in the sky at once.......Veil, Wild Duck, Double Cluster, M31, M57, M27, M56, M13

Personally speaking, I think Winters are better for the longer nights and I also prefer the Winter constellations including Taurus and Orion, of course, my favourites

Longer nights are great but for me personally i enjoy the darker mornings. Get up a little earlier and get in a good session before running for the train. But the darker evening are wasted. By the time i get in from work, have dinner, see the kids and sit down with my wife, it's never earlier than 10pm before i can get out.

[ollypenrice]

Winter skies look clearer subjectively, for some reason, but aren't. Looking at the circumpolar objects confirms this.

Certainly where I live (Lat 44) there is no need for dewheaters in the summer but in winter they are essential. The sky, therefore, is far drier in summer than in winter, as confirmed by our weather stations. OK this is at ground level but you still have to look through what's there.

Of course, the long nights and early starts of winter are wonderful but what can be better than the summer Milky Way arching overhead, the Great Rift splitting it around that mysterious centre?

I love 'em both, though being well south of the UK means a minimum of four hours' darkness, which changes everything.

The role of the jetstreams seems to be to push aside the flow of cold northerly polar air before it gets into mainland Europe. Living in mainland Europe I am naturally happy to see the UK keep the polar stuff all to itself!! (Runs for it...)

It has been suggested that in quiet sun years the jetstreams slow down and we get more of your polar air than we'd like. Roll on sunspot maximum!! This theory does seem to agree with recent observation but that is hardly conclusive.

Olly

[studio1one]

There is one very simple answer to this question.

YES!!

[martin_h]

I seem to remember this conversation taking place last summer - remember the BBQ summer?? No I thought not!

Roll on winter everyone was saying, crisp clear skies. What did we get? Snow! Where does snow come from.....ruddy great clouds.

[dazmoraz]

i bought myself a scope last xmas and i froze my knackers off looking through it!

[hemihaggis]

56 degrees north , is only dark for about 3 hours a night , and evenj then its not proper winter dark , at midnight at the start of july i could read a newspaper outside . roll on winter ....