1

Just Chat! / Does anyone have a tried and trusted method for stretching leather boots?

« on: 13/01/2010 02:38:46 »

Just bought some new boots. The left one fits like a glove but the right one is tight. I have walked around in them to try and stretch them but no luck. So Does anyone have a tried and trusted method for stretching leather boots?

Ta.

2

The Environment / Is increased snow fall a sign of a climate cooling trend?

« on: 10/01/2010 20:44:29 »

Is increased snow fall a sign of climate cooling

Yes and no. Yes it's a sign of the climate cooling in the short term, days or weels. But No, it's not a sign of long term cooling...but it also could be. It's complicated.

What we can say with confidence it that it is not caused by Global Warming/CC. People may use this a sign that CC is or is not real, but either way it's too early to tell, 30 years too early. It could be simply a sign of cyclical cooling but that again will have to wait for 30 years (or so) for us to know.

The main problem is that in this 24 hour media age everything is blown up and there has to be spin because news is on the hour every hour with updates every 15 minutes. Headlines need to be big and bold and they dont always reflect the truth too well. Headlines and official figures are not always the whole story.  For Example:

From Philip Eden. Ex Vice President of the Royal Meteorological Society:

the summer floods of 2007, which turned Tewkesbury into an island. Much was made of the claim that May, June and July comprised the wettest such three-month period in 242 years of records. It was a key statistic in the Government's review of the official response to the floods.
Sounds truly exceptional, doesn't it? It allows ministers to use the U-word - "unprecedented". But it was only the wettest May-to-July period. If you look at all the three-month periods on record, May-July 2007 was merely the 42nd wettest; in other words, such a large total will recur once every six years, on average. In fact, higher rainfall totals occurred in the winter of 2002-03 and the autumn of 2000.
It is important to emphasise that it is not normally a whole season's rainfall that creates a flood. The flooding during the of summer 2007 was associated with individual downpours that each lasted 24 to 48 hours.
The seasonal rainfall total contributes to groundwater levels - during a wet summer, the saturated ground allows individual floods to develop more quickly and to become more extensive - but the great majority of summer floods in Britain in the past were caused by one- to two-day downpours during wet seasons.
In that respect, 2007 was not unusual and cannot be regarded as "unprecedented" even within a generation, far less the 240-odd years of reliable rainfall records.
do you remember the "drought" that preceded the downpours? The abiding memories of the drought of 2005-06 were the doom-laden warnings of the water industry Jeremiahs that never quite materialised, and the disgraceful manipulation of rainfall statistics by organisations that should have known better..
Rainfall records for a small area of Hampshire and Surrey, the driest part of the country, were presented as if they referred to Britain as a whole. In the final analysis, the 2005-06 drought did not even make the top 40 since comparable records began in 1766.
One water company spokesman described the spell at the end of June 2005 as "eight months of almost unprecedentedly dry weather". He could get away with it - just - because of that little word "almost", but he knew that everyone reading it would focus on the word "unprecedentedly".
Using his technique one might suggest that such a comment is almost a bare-faced lie. More to the point, how would we have coped if we had endured a real drought along the lines of, say, 1975-76?
What we are lacking these days in the reporting of severe weather events are proper historical and statistical contexts. Destructive summer floods such as those of 2007 have happened before: in 1986, in Wales and north-west England; in 1968, across the West Country and the Midlands in July and in London and the South East in September; in 1930 and 1931 in Yorkshire; and in 1912 in East Anglia.

Although the ongoing cold spell is breaking records in parts of the Northern Hemesphers, perhaps one quote from Philip Eden should be remembered:

Extreme weather is part and parcel of our climate and it is wrong to treat it as new every time it happens...Calling such events "unprecedented" provides an excuse for failure for those we pay to maintain the infrastructure.

Philip Eden:
http://www.weather-uk.com/

It is also wrong to say that this winter was not forecast. Back in June Accuweather's Cheif Meteorologist Joe Bastardi forecast that the coming winter would be colder than anyone else forecast. Forecasting a "very special winter" for America, Asia and Europe. His forcast being based on the El Nino and a cold PDO.
But what nobody could forsee was what was going to happen to the AO, Artic Oscillation. As Al Gore spoke in Copenhagen the AO went in to, and is still in a negative phase. This turned the weather on it's head. Forecasts based on statistics and averages went out the window and those like Joe's turned out to be cautious.
So it's really impossible to say what the consequences from one event are or will be in the grand scheme of things. But we need to know that a summer of record highs does not validate global warming and a winter of record lows does not dismiss global warming. Only the stats can do that, on then it depends on who's stats you read and what data may or may not be missing.

3

The Environment / Why is lightning a blue colour?

« on: 30/12/2009 22:13:19 »

I may be wrong but isn't lightning white? As for coloured lightning and again I may be wrong but I think the colour of lightning depends on atmospheric moisture/water vapour, pollution/aerosols, the time of day and the severity of falling rain or even hail.

It's (iirc) to do with scattering and absorption of different wavelengths. I'm not clever enough to try and explain this but depending on what's between the lightning and you affects the colour you see. One example of this is during a violent theunderstorm, you may have heard that the cloud appears green in colour. One theory for the green colour is that rain and or ice absorbs the red colours and the cloud itself absorbs the blue leaving the green. This then is what makes the lightning from that cloud system look green or blue.

An area of high concentrations of ozone can make lightning look blue. You also get yellow, purple, white and pink lightning. White lightning, as well as being the cider of choice for teenagers, is also lightning that occurs in a dry atmosphere

For examples of how the severity of rain and  the rain curtain can affect the colour of lightning, this link has some pictures:
http://www.nightskyhunter.com/Lough%20Neagh%20Thunderstorm%20-%20April%2025th%2009.html

A quick look on the net gives this:

NOAA NSSL severe storms lab
"Lightning can appear to be many different colors depending on what the light travels through to get to your eyes. In snowstorms, where is somewhat rare, pink and green are often described as colors of lightning. Haze, dust, moisture, raindrops and any other particles in the atmosphere will affect the color by absorbing or diffracting a portion of the white light of lightning."
http://www.nssl.noaa.gov/faq/faq_ltg.php

And this from the weather guys at USA Today:
"In researching this graphic, I came across several theories regarding the cause of colored lightning. Some posit that it is the concentration of gases at the point of the strike that result in different colors. This explanation doesn't ring true to me as the lower atmosphere is very well-mixed and would not likely show significant differences in concentrations to result in lightning coloration. David Cook from Argonne National Laboratory agrees, "There has to be a significant concentration of particular chemicals that create colors during ionization; those concentrations don't occur even in highly polluted air."
Another explanation that is sometimes offered is that it is variations in the temperature of lightning that result in the different colors. Again, David Cook weighs in:
Lightning light in the troposphere is white, and includes all solar visible wavelengths, no matter what the temperature of the lightning. The temperature of lightning actually varies little from the weakest to the most energetic of strokes and is equivalent to or higher than the temperature of the surface of the sun."
http://blogs.usatoday.com/weather/2008/07/what-causes-col.html

4

The Environment / Why Was The First Few Minutes of snow..BIG Snow ?

« on: 26/12/2009 18:12:39 »

Sorry DiscoverDave.

I posted before fully reading your comments. You did mention temperature. My lazy Reading often leads to skipping words, sentances or even chapters...

5

The Environment / Why Was The First Few Minutes of snow..BIG Snow ?

« on: 26/12/2009 18:02:53 »

The one thing missing from (my quick scan) of the topic is temperature. Temperature also plays a part in the snow being "wet", "dry", big or small.

The larger, wetter flakes have fallen through relitively moist, mild air and can be as large as  2 cm in diameter.
The smaller flakes tend to be flakes that have fallen through cold, dry air.
You may notice the difference between the flakes when you try making snowballs. The smaller dryer flakes are not as good as the larger wetter ones.

Another difference is that the smaller flakes tend to be single flakes. These dry single flakes don't bind to eachother whereas the larger flakes, are actually make up of hundreds of smaller flakes that have bonded and stuck to eachother.

So another variable is the fall time from cloud to ground. Not only is it the temperature of the cloud, the air the flakes falls through and the avaliable moisture within the cloud a factor but the fall time.
A longer fall time allows more wetter flakes to stick to eachother as they fall.

The wind strength can also affect the size and shape of the flake. Stronger winds may shred the snowflake or rip/snap parts off causing odd looking and smaller flakes.

There are a lot of factors that go in to producing the flakes on your lawn, but I would stick with the answer that the flakes winessed by Neilep were because of the way the avaliable moisture was used up. I say that due to the speed of change and that there was relatively little wind during last weeks fall.

As an aside, snowflakes are not all hexagonal theyare quite commonly triangular in shape. And they are not always White. Snow has fallen (iirc) red, blue and black/grey. 

The largest reported flakes were in Montana sometime in the last centuary. They were reported to be pizza sized flakes! I don't know if this is true or if Montanans had pizza in the late 1800's early 1900's. 

6

The Environment / Does the amount of cloud remain constant?

« on: 25/12/2009 13:01:48 »

Presently, global cloud cover is fairly constant with between 65 and 68% of the Earths surface. But this hasn't and isn't always the case. These figures seem to change on a 30 (ish) year cycle.

Between the years 1960 and 1987 cloud cover increased above most continents. More noticable were the increases over the US of 10% and of 5% over Europe. This was the cause of Global Dimming

From 1987 to 2001 global cloud cover decreased by 4% and we are now in an increasing state / phase / cycle.

What you don't want to do is get bogged down in a global warming dispute over cloud cover and how it affects the models. The variables are too great unless this is your field of study or expertise.
Reason being that, for one, it depends on the atlitude and latitude of the clouds and this is something we can't predict.

Low and mid level cloud is increased by urban pollution and again this increase is dependant on the volume of airbourne pollutants. While air traffic leads to an increase in high altitude cloud.

The circulation of the atmospheric can also affect cloud cover. circulation. Low pressure systems have greater cloud cover associated with them than high pressure systems.

Try googling the "nternational Satellite Cloud Climatology Project"

7

The Environment / Why Was The First Few Minutes of snow..BIG Snow ?

« on: 24/12/2009 16:33:01 »

Why's that then ?..why was the first few minutes of snow big fat snow ?

because of the avaliable moisture In the atmosphere. The bigger flakes indicate that the atmosphere has a high moisture content, as this moisture is used up by making the larger flakes there is less moisture avaliable so you get smaller flakes.