"ron button" wrote in message
...

"Len Wood" wrote in message
...
On Thursday, November 6, 2014 5:52:19 PM UTC, Scott W wrote:
On Thursday, 6 November 2014 09:16:16 UTC,
wrote:
Quite impressive. Below freezing widely in SE and Central Southern
England (eg -2 in Wokingham) but + 6.7 deg as I arrived at work on
Fleet Street just after 0800.

I'm 7.2 miles as the crow flies east from Fleet Street and it was -1.3C
before the temp began rising at 0658z. I ride in most days and it always
amazes me the difference in just a few miles.

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There's an awful lot of underground passages and sewers under the streets
of London.

These unquestionably contribute to the UHI.
May be accounting for 3 Degrees according to Will's weekday/weekend
figures.

A good PhD (Piled high and Deep) topic for some geographer if you ask me.

Len

-----------------------------------------------------------------------------

Are the sewers colder at the weekends Len ?
Altitude also has a factor with calm nights,I live just a couple of miles
from Scott,but around 250ft,so on calm clear nights my mins are several
degrees above the lower lying places around here like Wanstead.

Ron,

The boundary layer lapse rate is ~9 K per km so I would expect you
to be 1 C below that recorded at lower lying places, especially if the
Heat Island effect is operative. Presumably, those places are in frost
hollows?

Indeed when I lived in the middle of industrial Stratford during the '63
winter which was very built up and heated by many coal fires (no central
heating in those days !),I clocked a minimum of minus 13C on the morning
of January 23rd..
Yes my clogs were too cold to wear without wrapping my feet with newspaper
first.......

LOL,

Cheers, Alastair.

On 08/11/2014 11:09, Alastair McDonald wrote:
"ron button" wrote in message
...

"Len Wood" wrote in message
...
On Thursday, November 6, 2014 5:52:19 PM UTC, Scott W wrote:
On Thursday, 6 November 2014 09:16:16 UTC,
wrote:
Quite impressive. Below freezing widely in SE and Central Southern
England (eg -2 in Wokingham) but + 6.7 deg as I arrived at work on
Fleet Street just after 0800.

I'm 7.2 miles as the crow flies east from Fleet Street and it was -1.3C
before the temp began rising at 0658z. I ride in most days and it always
amazes me the difference in just a few miles.

--

------------------------------
This email was sent by a company owned by Pearson plc, registered office
at
80 Strand, London WC2R 0RL. Registered in England and Wales with
company
number 53723.

-----------------------------------------------------------------------------
There's an awful lot of underground passages and sewers under the streets
of London.

These unquestionably contribute to the UHI.
May be accounting for 3 Degrees according to Will's weekday/weekend
figures.

A good PhD (Piled high and Deep) topic for some geographer if you ask me.

Len

-----------------------------------------------------------------------------

Are the sewers colder at the weekends Len ?
Altitude also has a factor with calm nights,I live just a couple of miles
from Scott,but around 250ft,so on calm clear nights my mins are several
degrees above the lower lying places around here like Wanstead.

Ron,

The boundary layer lapse rate is ~9 K per km so I would expect you
to be 1 C below that recorded at lower lying places, especially if the
Heat Island effect is operative. Presumably, those places are in frost
hollows?

Indeed when I lived in the middle of industrial Stratford during the '63
winter which was very built up and heated by many coal fires (no central
heating in those days !),I clocked a minimum of minus 13C on the morning
of January 23rd..
Yes my clogs were too cold to wear without wrapping my feet with newspaper
first.......

LOL,

Cheers, Alastair.



Alistair, I think you'll find that the top of the inversion doesn't
follow topography but is relatively constant. So higher ground can
easily be warmer than lower. For example, Will on Haytor can be above
any fog that might form and can certainly be warmer than surrounding
valleys - without them being frost hollows. To cite an extreme case, I
used to plot tephis at Heathrow and with some of the Canadian ones in
winter, the coldest part of the ascent was the surface!That was -40 or
thereabouts.

Ron, I see you were rich. You could afford newspaper!

On Thursday, 6 November 2014 20:48:06 UTC, Len Wood wrote:
On Thursday, November 6, 2014 5:52:19 PM UTC, Scott W wrote:
On Thursday, 6 November 2014 09:16:16 UTC, wrote:
Quite impressive. Below freezing widely in SE and Central Southern England (eg -2 in Wokingham) but + 6.7 deg as I arrived at work on Fleet Street just after 0800.

I'm 7.2 miles as the crow flies east from Fleet Street and it was -1.3C before the temp began rising at 0658z. I ride in most days and it always amazes me the difference in just a few miles.

--

------------------------------
This email was sent by a company owned by Pearson plc, registered office at
80 Strand, London WC2R 0RL. Registered in England and Wales with company
number 53723.

-----------------------------------------------------------------------------
There's an awful lot of underground passages and sewers under the streets of London.

These unquestionably contribute to the UHI.
May be accounting for 3 Degrees according to Will's weekday/weekend figures.

A good PhD (Piled high and Deep) topic for some geographer if you ask me.

Len

Luke Howard wrote about the urban heat island, though this was decades before Bazalgette and the Great Stink in 1858. It would be interesting to compare the figures before the sewerage system was built, say 1808, T.J Chandler's study in the 1960s and now...

--

------------------------------
This email was sent by a company owned by Pearson plc, registered office at
80 Strand, London WC2R 0RL. Registered in England and Wales with company
number 53723.

"Len Wood" wrote in message
...

There's an awful lot of underground passages and sewers under the streets
of London.

These unquestionably contribute to the UHI.
May be accounting for 3 Degrees according to Will's weekday/weekend
figures.

A good PhD (Piled high and Deep) topic for some geographer if you ask me.

Len

Len,

Is that due to them releasing methane, a powerful greenhouse gas? Or is
there some other theory?

Cheers, Alastair.

On Saturday, November 8, 2014 11:10:07 AM UTC, Alastair wrote:
"Len Wood"

There's an awful lot of underground passages and sewers under the streets
of London.

These unquestionably contribute to the UHI.
May be accounting for 3 Degrees according to Will's weekday/weekend
figures.

A good PhD (Piled high and Deep) topic for some geographer if you ask me.

Len

Len,

Is that due to them releasing methane, a powerful greenhouse gas? Or is
there some other theory?

Cheers, Alastair.
-----------------------------------------------------------------------------
I can't put my finger on it Alastair.
I am assuming the sub-terraining heat remains the same throughout the week.
There is more surface fabric heat to be retained at night, in the weekdays though.
I would imagine the difference between weekdays and weekends in central London has diminished in recent years though.

Len
------------------------------------------------------------------------------

"Len Wood" wrote in message
...
On Saturday, November 8, 2014 11:10:07 AM UTC, Alastair wrote:
"Len Wood"

There's an awful lot of underground passages and sewers under the
streets
of London.

These unquestionably contribute to the UHI.
May be accounting for 3 Degrees according to Will's weekday/weekend
figures.

A good PhD (Piled high and Deep) topic for some geographer if you ask
me.

Len

Len,

Is that due to them releasing methane, a powerful greenhouse gas? Or is
there some other theory?

Cheers, Alastair.
-----------------------------------------------------------------------------
I can't put my finger on it Alastair.
I am assuming the sub-terraining heat remains the same throughout the
week.
There is more surface fabric heat to be retained at night, in the weekdays
though.
I would imagine the difference between weekdays and weekends in central
London has diminished in recent years though.

Len
------------------------------------------------------------------------------

When you wrote "Piled high and Deep" I thought you were referring to sewage
that was causing the HI effect! If that had been the case then I doubt you
would have wanted to put your finger on it :-)

But I am interested in this. If it is methane then it would fit with my
other research. Is there any evidence to show that sewers do contribute to
the HI?

Cheers, Alastair.