mike Meehan

Many a true word...........snow over the Atlas Mountains - certainly not an impossibility

Don't forget folks that a lot of this precipitation is snow to start off with - it's just that it melts on the way down

I would say that in a situation such as this it is never over until the fat lady sings - there is always a chance that the Scandi High could re-invigorate, block the Atlantic and maintain the easterlies but probably not on this occasion, though stranger things have happened.

I usually look at my windows, not 100% accurate but usually you can see wet drops arriving as wet drops, though there is the heat of the house which can melt snow if it is just below freezing, wet snow you can normally see the the flake before it melts and with dry snow there is not normally any adherence to the glass - plus it saves going out in the cold to see the cloches. Car windscreens are good as well and have the added advantage of being able to see the flakes in the headlights at night - it generally follows the same rules as above but at -5C and below the snow does not normally stick the the windscreen when the car is in motion. Another indication I use is to watch the surface of puddles - drops of water mixed in the precipitation will cause small splashes, though hail could do the same but snow does not make the same splashes, then there is the sensation as it hits your skin water feels wetter than snow. I find this is good most of the time but there are occasions when you have to concentrate to discern the difference between drizzle and 'snizzle, both of which can occur at below freezing.

After they made him they broke the mould - He was a star! - I always loved the Sky at Night - not only that he was quiet a good musician and cricket was his other love.

I'm not quite sure what you are getting at Kon. Pressure decreases with height because as you get higher there is less atmospere above you, so the weight becomes less and it is the weight of the atmosphere which causes the pressure but it is not a straightforward linear graph but exponential.

I love blue skies and tend to get a little depressed if we go too long without sunshine - fair weather cu are ok and very nice to look at and the occasional storm adds interest. We had a Bartlett high when I did my gliding course during the early part of 1959 - it was generally cold and I could have sworn that there were slivers of ice on the wing of one glider which had just landed - launches generally gained just short of 1000 feet and that day you could just skirt with the bottom of the cloud base - towards the end of the course it cleared up a bit and my instructor managed to find a thermal.

Aircraft are fitted with aneroid altimeters which work on the pressure of the air which varies with height, however it is important that they are corrected during flight with the insertion of sea level pressure and this is known as the QNH. When a pilot is using this it is important also for him to know the height of the airfield where is is landing so he can make the necessary adjustment. Another setting is known as the QFE and this is the setting at a particular airfield. On the altimeter there is a little knob which is turned until the pressure given appears in the window - this is done manually. What normally happens in practise is the pilot will get updates during his flight from air traffic control so he will be able to maintain an accurate height - this is very important because with the amount of traffic in the sky aircraft travelling in different directions have to maintain different flight levels to avoid chances of a collision in the air. Nowadays most aircraft commercial aircaft also have altimeters which are based on reflecting a radar signal off the ground and this too can show the height of an aircaft but since it operates through electricity they is a chance of this failing whereas the old fashioned aneroid altimeter operates purely on air pressure and there is little that can go wrong with it, so these are always fitted as far as I am aware and a necessary backup. The other method of finding one's height these days is through the use of a GPS (SatNav) - most of the time these are fairly accurate but there have been times when driving a car in coastal regions I have felt the need to have a periscope fitted because SatNav indicated I was driving below sea level!

About a half hour ago I noticed that some of that white stuff was coming down, light to moderate but not settling, still falling as sleet, not so heavy, temp dropped from 2.5C to 2.2C, now rising a tad to 2.3C.

I am no expert but I think it indicates that the conditions where they have come from are quite severe, for example in Scandinavia and northern Russia at the moment, so, especially if they can get a favourable wind, they head for 'greener' pastures where more food is available. There may be a certain amount of truth in our winters being more severe because, if, as per my example, the Scandinavian/northern Russia winter is severe, there is always a chance of the cold overspilling to reach our area with the right synoptics.

Peter Cockroft reminded me of the spell we had of foggy weather 50 years ago when it was a real pea souper of freezing fog. It was probably the last we ever had like that because shortly afterwards the Clean Air Act kicked in. At that time I was a scientific assistant at Heathrow and recall a temp of virtually a -5C for a few days. December of 1962 was pretty cool with ice starting to form on the Thames - my mate Banny had a houseboat on the Thames near Richmond and there was ice on his walls ON THE INSIDE!

http://uk.news.yahoo.com/london-sydney-spaceflight-edges-closer-162046726.html

Thanks RP - I do note that entropy occurs in an isolated system though, so does this mean that if the universe were to be infinite we would no longer have a isolated system, therefore no entropy? The other point I raised in post 14 is that the 'big bang' must have had a trigger to set it off, so if this were to be the case the trigger must have been in existence before the 'big bang' Any comments?

It took me a long while to be convinced of the' big bang' theory but now I am getting used to the idea but there must have been a trigger point to set this off in the first place and if this was the case then something must have existed pre big bang, or just as stars have life cycles might the same thing apply to universes?

For entropy could we say variations and don't the variations we have in nature push forward evolution?

My little brain tells me that the ice ages were not caused just by one event but a number dovetailing to create the event, simliar to the recent of flooding of New York being a consequence of both high on shore winds associated with Sandy and a higher than normal high tide making landfall at the same time. The world climate is controlled first of all by the energy from the sun which can vary especially when you consider that the Earth's orbit is somewhat eliptical meaning that at different periods of time, say the northern hemisphere is more favoured than at others. It is also suggested that through periods of time there are some fluctuations in the actual output of energy from the sun. With continetal drift we have a gradual changing of the landmasses and here the Antarctic typifies the tendency to be colder than the Arctic because the former consists of a landmass whilst very much of the latter is sea. In addition to the changes in landmass and energy received we also get changes in the ocean currents which can be further changed by variations of salinity. On top of this greenhouse gases which do not just mean CO2 but include methane and water vapour also have an effect. On the other hand water vapour is required to kick start an ice age because this will fall as snow in the hight latitudes and altitudes and without a significant layer of snow I doubt that an ice age as we know it would begin. So we need moisture to make the snow especially during the winter and colder summers to slow the melt so the areas of snow and ice gradually increase - as they do they will reflect more energy away and become colder - as they become colder these areas will increase in size and this system will feed on itself causing glaciers in high latitude and high altitude regions to form and continue their expansion until they reach the warmer areas at sea level at lower latttitudes until eventually we end up with the limit of ice extending to St Johns Wood in London as it has done in the past. CO2 is closely associated with the formation of ice ages and less of it means colder conditions and more warmer conditions but we are not totally sure of the mechanics governing this, though there is a suggestion of carbon hungry plant life gulping it out of the atmosphere thus causing cooling. Volcanic action can also have an effect - a great deal of ash and sulpher dioxide pumped into the atmosphere can shield some of the sun's energy from reaching the surface causing cooling whilst at other times volcanoes can spew out a lot of carbon di-oxide leading to warming. The interesting thing is that the last encroachment of ice finished pretty quickly about 12000 to 15000 years ago, which is a short time by geological standards, so there must be tipping points in both ice formation and melting. So I would suggest to kick start, snow and lots of it in the winter coupled with minimal melting in the summer to allow the ice to build up in the first place, then after a time an equilibrium is reached where there are drier periods but the cold does not allow for very much warming and finally a warming period which melts the ice.

Thinking about solar panels and going from the sublime to the ridiculous, is there a stage whereby the number of solar panels absorbing the energy from the sun could affect the amount of energy being absorbed by the atmosphere? I would have thought that at today's usage the effect would be minimul, but say, if we were to cover 10% of earth's surface with solar panels, would this have an affect? I am thinking along the lines of the principal that you can't have your cake and eat it and any energy taken by the solar panels would mean that much less for the atmosphere.

Maybe this will convince them now.

My daughter living at Bedmond in Herts told me that there was a covering of snow first thing in the morning but it soon melted. It seems that snow in October is becoming more prelevant.

Interesting post - It just shows what can happen when you get a number of factors 'dovetailing'. I would expect that at ground level the 'ventura effect' could cause localised higher gusts as the wind passes through a series of largish buildings. The approaching 250mms of rain would not help either with it being unable to drain away into a surge tide. It was well forecasted and gave the authorities some time to get emergency procedures, such as evacuation, into operation. It brings back memories of our 1953 'North Sea Sea Surge', which wasn't so well forecasted at all but this really shows the advance in technology and techniques over the years rather than anybody falling down on the job - London is now better protected than what it was with the Thames Barrier but the topography of New York Harbour does not lend itself a similar contruction. I expect the alternative they will consider would be higher sea walls which would be a considerable undertaking. Thank God they closed down the subway. It also reminds me of the floods we had in the area of France a few years ago, where we are at the moment - here gale force SE winds forced a 'high tide' causing the water to back up into the Aude whilst torrential rain in the Corbiere area was trying to drain out, the result being that Cuxac d'Aude, about 5 miles south of us, was under 2 metres of water. Now they are building extensive flood drainage channels.

So that is how the biblical scourge of rivers running red arose.

Can't remember the weather on 24.10 2011, though it is her birthday but generally the last two weeks of October were merde in the south of France with quite a but of LP in the Med and on the way home at the beginning of Nov lots of the vinyards prior to reaching the Massif were flooded. This year, it is quite different, virtually no cloud and calm with a temp of 23C inland and 20C on the coast where spent an agreeable afternoon.

I remain optimistic that if they search hard enough something will be found, though the problem will be avoiding contamination.

That is exactly the point I was trying to make that it is not expedient for many to decrease their carbon output; that is why I am trying to look at other methods of trying to keep the CO2 in balance. I did not know about the Azolla Event but it is comforting to know that nature is not so daft as the species, Homo Sapien, which sometimes appear to be a contradiction in terms. But no doubt this event occurred over several millenia which is time we do not have. So as I understand it, the melting ice caps would form a layer of fresh water over the arctic regions which when warmed allows the Azolla to propagate and in doing so it absorbs the CO2 from the atmosphere, though to seed all our fresh water lakes which would be suitable would create havoc with their eco systems but it is being used on a more minor scale who use it in flooded paddy fields in order to create a fertiliser for the later rice crop. If we are to redress the carbon balance some kind of geobiological engineering would appear to be necessary and this would not be quick either. Not only that we would have to be careful not to produce something which does not have a runaway effect and could be kept under control - that is the reason I suggested, for example the irrigation of the Sahara Desert through desalinated water, though it would be a gigantic undertaking with political/social problems to take into account along the way. I would be interested to hear what proposals you may have along these lines.

Just assuming that all these blokes wearing sandwich boards portraying the message 'The End is Nigh' are correct, we are not getting a lot of success in obtaining international agreements to limit the amount of CO2 and other greenhouses gases discharged into the atmosphere - the Americans have never been wholehearted about these different agreements and the developing countries quite natuarally want to catch up with the west but in the course of doing so using older technologies which put out CO2, the degree of ice melt in the arctic summer seems to be a clarion call to those who fill us us with yet more foreboding, despite 4WD's post indicating that climate change and melting ice were big topics of conversation back in in the 30's, 75 years ago, so if these are correct and some appear to consider that action is urgently needed, what are we going to do? Clearly the idea that all the countries of the world should co-operate in the urgent reduction of the greenhouse gases isn't working since they need sources of power to improve their economies. The other alternative as I alluded to a couple or so posts ago was to concentrate on the biospere and literally enrourage the growth of 'carbon sinks' First and foremost immediate action should be taken to prevent any further destruction of the rain forests, Secondly a long term project could be started by nibbling away at the desert regions of the world by using solar energy, of which there is an an abundance, to desalinate sea water to use for irrigation whereby a mixture of trees and cash crops could be planted. These trees and crops would put out water vapour in the atmosphere in those regions which would have the effect of making the air less moist, initially having little effect on the local weather conditions but this increases with the increases in area under cultivation - a few thousand years ago the Sahara desert was much more fertile with forests growing along the coastal areas and was in fact used as the 'bread basket' by the Romans. The extra vegetation would help in taking some of the CO2 out of the atmosphere, it would help cool the region if done on a large enough scale, the dead and decayed vegetation would help fertilise the soil and these would have an added benefit of contribuiting more food to help the world's increasing population. We have the technology to do this now. Doubtless it will be an extremely long process covering several centuries but wouldn't it be better to start the process now instead of sitting about wringing our hands in despair? As it is at the moment the desertification of our world is increasing and with the will and use of modern technology this does not have to be the case.