Stormy Weather

[Serial_Apologist]

Be that as it may, records going back to 1766 isn't anything like far enough to make any assumptions, being a mere tiny speck in the history of the globe. I remain unconvinced that 'climate change' is anything to do with human activity and is no more than a normal cyclical change. Attributing the current crop of storms, the tiniest of tiny specks in terms of historic time, to 'climate change' is something that cannot be proved beyond any doubt and this report is actually saying as much in muddled and confusing language which is classic bureaucratic fence-sitting.

Ice cores correlating increases in CO2 with industrialisation since circa 1800?

[David-G]

I'm not sure that this is what they are saying. Take this for example:

"We have records going back to 1766 and we have nothing like this," she said. "We have seen some exceptional weather. We can't say it is unprecedented but it is exceptional."

The report links the recent extreme weather in Europe and North America to "perturbations" in the North Atlantic and Pacific jet streams, partly emanating from changing weather patterns in South East Asia and "associated with higher than normal ocean temperatures in that region".

"The attribution of these changes to anthropogenic [caused by humans] global warming requires climate models of sufficient resolution to capture storms and their associated rainfall".

If anyone can make any sense whatever out of the closing paragraph I'd be grateful for a translation into plain English.

Be that as it may, records going back to 1766 isn't anything like far enough to make any assumptions, being a mere tiny speck in the history of the globe. I remain unconvinced that 'climate change' is anything to do with human activity and is no more than a normal cyclical change. Attributing the current crop of storms, the tiniest of tiny specks in terms of historic time, to 'climate change' is something that cannot be proved beyond any doubt and this report is actually saying as much in muddled and confusing language which is classic bureaucratic fence-sitting.

Petrushka, is the paragraph that you would like "translated" this one:

"The attribution of these changes to anthropogenic [caused by humans] global warming requires climate models of sufficient resolution to capture storms and their associated rainfall".

If so, I will do my best to "translate" for you.

[Serial_Apologist]

Petrushka, is the paragraph that you would like "translated" this one:

"The attribution of these changes to anthropogenic [caused by humans] global warming requires climate models of sufficient resolution to capture storms and their associated rainfall".

If so, I will do my best to "translate" for you.

I for one would be very grateful, DG.

[Petrushka]

Petrushka, is the paragraph that you would like "translated" this one:

"The attribution of these changes to anthropogenic [caused by humans] global warming requires climate models of sufficient resolution to capture storms and their associated rainfall".

If so, I will do my best to "translate" for you.

Yes it is. I find it meaningless waffle basically saying that they haven't got a clue.

[Serial_Apologist]

Yes it is. I find it meaningless waffle basically saying that they haven't got a clue.

It's probably some underling's summation of what someone authoritative said more precisely. But, what about those ice cores?

[David-G]

"The attribution of these changes to anthropogenic [caused by humans] global warming requires climate models of sufficient resolution to capture storms and their associated rainfall".

I can try to explain the statement; but I cannot vouch for the conclusion which is drawn.

I first have to try to explain how these climate models work. They are similar to the models used to forecast the weather. The region of the atmosphere to be modelled – which may cover the whole world, or may cover a more restricted area – is divided into a large number (many millions) of boxes, called cells. The sizes of the cells are typically between 3 and 200 miles, depending on the model. Each cell contains a pressure value, x- y- and z-velocity values, a temperature value, a humidity value, etc. Each of these values is thought of as being representative of the whole cell. The task of the model is to predict how these values in the individual cells develop with time.

The models are based on the fundamental physical laws governing fluid motion, expressed in mathematical terms. These represent conservation of mass, conservation of momentum, and conservation of energy (heat). Thus for example, conservation of mass requires that at any given time, the total mass flow out of a cell balances the total mass inflow into the cell. Momentum conservation includes the effect of forces such as pressure gradient, and coriolis forces due to the earth’s rotation. Energy conservation includes effects such as solar heat gain, and latent heat effects due to condensation or evaporation of water droplets.

The conservation laws, which are represented as partial differential equations, are approximated as "difference equations" connecting the pressure, velocity, temperature values in adjoining cells. The whole system of difference equations can be thought of as a set of millions of simultaneous equations. A complex mathematical algorithm is used to solve the equations, i.e. to work out the values of the variables in the individual cells. This is an immense computing task, requiring some of the most powerful computers in existence, and taking hours or days to calculate.

Climate models, as opposed to weather-forecast models, may need to include additional effects, such as interaction with the oceans and with sea ice.

The size of the computational task is determined by the number of cells used in the model. Using smaller cells allows prediction of local effects in greater detail, but more cells will be required, increasing the overall computational time requirement. For any given complexity level of modelling, the practical limit on the time taken for the model to run will dictate a minimum practical cell size.

What the statement is saying (I cannot vouch for the accuracy of it) is that the individual cells in a climate model are too large to properly model the dynamics of individual storms. (This is a little bit like a digital photograph, where the individual pixels limit detail that can be made out.) The statement is saying that to predict the behaviour of individual storms, and their associated rainfall, in the context of a large-scale climate model, a finer grid of cells would be required. To do this would require more powerful computers.

[MrGongGong]

Ah, that's the one thing that's not been organised, as far as I am aware, Pabs. The government are always quick enough to send aid out to other countries, but when it co0mes to their own, they just seem to bury their heads in the sand!!

Erm
Whilst its obviously no fun being flooded in Somerset
there is a huge difference between this and disasters in other places that we quite rightly send aid to, no one is going to get malaria , starve to death or have to live under a plastic sheet!
The ridiculous nonsense that one hears from a certain loudmouth comedy politician suggesting that the UK stops sending bribes OOOOPS I mean AID to India etc in order to fund the clearup just shows (again) how ignorance and "common sense" are often bed partners.

[Petrushka]

Thanks for taking the time to reply, David-G, and while I can grasp the basis I'm afraid most of this goes over the top of my head.

[MrGongGong]

Thanks for taking the time to reply, David-G, and while I can grasp the basis I'm afraid most of this goes over the top of my head.

Does that make it "waffle" ?
Seems fairly simple to me, think sample rates
or reel to reel tape

15 vs 30 ips

and so on

[David-G]

Thanks for taking the time to reply, David-G, and while I can grasp the basis I'm afraid most of this goes over the top of my head.

The gist of it is that it's not too difficult to model small-scale things (storms in this case), or large-scale things (e.g. the whole earth's climate); but to do both simultaneously requires very much greater computational resources, exceeding what is currently available.

[Serial_Apologist]

The gist of it is that it's not too difficult to model small-scale things (storms in this case), or large-scale things (e.g. the whole earth's climate); but to do both simultaneously requires very much greater computational resources, exceeding what is currently available.

These concepts are difficult for the layperson to understand, so I'm grateful for your taking the trouble to explain them in as straightforward a manner as the subject allows, David-G.

[David-G]

I saw Peter Grimes at the ENO last night. (Wonderful!) It seemed very prescient of our present weather, as shown by these extracts from the libretto.　

Chorus of Fishers

And if the spring tide eats the land again

Till even the cottages and cobbled walls of fishermen

Are billets for the thievish waves which take

As if in sleep, thieving for thieving's sake –


　

Balstrode (looks seaward through his glass)

Look! The storm cone!

The wind veers

In from the sea

At gale force.

Chorus

Look out for squalls!

The wind veers

In from the sea

At gale force.

Make your boat fast!

Shutter your windows!

And bring in all the nets!

All

Now the flood tide

And the sea-horses

Will gallop over

The eroded coast

Flooding, flooding

Our seasonal fears.

Look! The storm cone

The wind veers.

A high tide coming

Will eat the land

A tide no breakwaters can withstand.

Fasten your boats. The springtide’s here

With a gale behind.


Boles (passionately)

God has his ways which are not ours:

His high tide swallows up the shores.


Omnes

O Tide that waits for no man

Spare our coasts!


(Bob Boles and other fishermen enter. – The wind howls through the door and again

there is difficulty in closing it.)

Boles

Did you hear the tide

Has broken over the Northern Road?

(He leaves the door open too long with disastrous consequences. A sudden gust howls

through the door, the shutters of the window fly open, a plane blows in.)


Fisherman

There’s been a landslide up the coast.


Ned

Have you heard the cliff is down

Up by Grimes's hut?


Mrs. Sedley

The carter’s over half an hour late!

Balstrode

He’ll be later still: the road’s under flood.


Hobson

The bridge is down, we half swam over.

[amateur51]

These concepts are difficult for the layperson to understand, so I'm grateful for your taking the trouble to explain them in as straightforward a manner as the subject allows, David-G.

I've read David-G's piece three times now & I've got the hang of it - many thanks

[BBMmk2]

The locals in the worst affected areas are continually mentioning about a lack of dredging in the rivers nearby. When it's too late, the government sits up and listens!!!

[Richard Tarleton]

The locals in the worst affected areas are continually mentioning about a lack of dredging in the rivers nearby. When it's too late, the government sits up and listens!!!

Excellent piece in yesterday's Sunday Times by Charles Clover. The silt which the rivers on the Levels are full of and which the farmers want dredged is topsoil from their farms. There's been a shift to growing maize instead of grass, to feed to cattle. Maize is harvested in autumn, leaving bare soil vulnerable in steep catchments, like the Tone. [Its root-mat also contributes greatly to run-off, something he doesn't mention]. An Exeter University study says that about half the sediment transported downstream by the River Tone comes from erosion from maize fields. When it gets to the Parrett, it meets silt washed upstream by the tide.

In other words, it's in part down to [changing] land use in the catchment. By the time the silt ends up in the rivers, it's too late. He goes on to compare and contrast the Levels with the Fens and the Camargue. It really is an excellent piece.