on 18 April 2007
Not bad but I didn't find it gave very clear explanations of how the weather works ie the dynamics and laws that explain how weather systems develop. Nor did was there much helpful information about forecasting. The problem was partly that the book spent time on the wrong issues (for me). There was lots of space devoted to describing the weather in different parts of the world (including a lot of unappealing detail at the front and another long section at the back describing weather in different cities). But there was comparatively little space given to explanations of how weather systems work and still less to forecasting. The other problem was that I didn't find the writing very clear. The explanatory material needs an introduction giving an overview of the big picture. For example, it talks a lot about the warm air masses and cold air masses - well, does the whole lower atmosphere consist of these? If not, how do they interact with other parts of the atmosphere? And then, for example, where do winds come from - do they just consist of moving air masses or movements within air masses or what? This kind of overview was lacking. On the other hand, the book is reasonably comprehensive in its coverage. And it would be good for someone who wants to know what the weather is like in different parts of the world.
on 19 June 2007
For me this book was a real disappointment. The format is handy and the illustrations are attractive, but that's as far as it goes. The book falls down heavily on the text and what would appear to be abysmal editing. The figures and illustrations have no numbers and the connection between them and the text is never specified. The reader is often left looking at a figure and wondering which bit of text it refers to.
I got as far as p.27, with the following observations, before deciding to go to a later section to see if there was any improvement.
p.8 `The average change in temperature from the surface of the Earth up through the atmosphere is generated from vast numbers of thermal observations taken by meteorologists ......' This seems to suggest that there was no average change in temperature until meteorologists appeared on the scene.
p.8 `Zonal mean is the average of all the separate values within a latitude band'. This legend refers to a globe coloured with various shades of blue. Do these signify temperature, and if so, of what? Of air, sea, land?
p.10 `The gases that comprise the `dry' atmosphere occur in fixed proportions up to about 100 km (62 mi) above sea level. This well-mixed layer is known as the turbosphere ....' The illustration on the previous page shows the turbosphere extending to a height of only 80 km.
p.10 `This region [the turbosphere] is capped by the `turbopause' .... The illustration on p.9 does not show a `turbopause', but shows the turbosphere being capped by a `mesopause'. Are mesopause and turbopause the same thing?
p.11 `Air at the harbourside in New York is about 3% denser than the air at the top of the Empire State Building.' According to the table on p.10 it is 5% denser (air density 1.23 kg/m3 at mean sea level, and 1.17 on Empire State Building).
p.14 `This layer [the stratosphere] extends up to 50 km (31 mi) above sea level'. According to the figure on p.9, it extends only up to 45 km above sea level. Quite possibly there are seasonal or other variations that would encompass both these figures, but if there are, no explanation is given.
p.14 The figures showing the reversal of polar stratospheric winds from winter to summer have big red lines going across Arabia and North Africa. Is this really where the polar stratospheric winds are situated, and if so, why? There appears to be no explanation in the text.
p.15 `The existence of ozone at these levels is due to the splitting , or dissociation, of oxygen molecules into two oxygen atoms by the action of that same short-wave radiation'. This statement leaves us with lots of individual oxygen atoms; there is no further explanation as to how or why three of these should then link up to form ozone.
p.17 The right-hand column of the table showing the components of the thermosphere is headed `Fraction of total molecules'. Most gas concentrations in the table are given in parts per million (e.g. helium, `5 parts per million'), but four are presented decimally (e.g. oxygen, `0.2095') with no mention of units. Does this mean that the thermosphere contains 0.2095 ppm of oxygen, or does it mean that it contains 209,500 ppm?
p.22 `The principal warm ocean currents of the southern hemisphere are known as the Brazil and Agulhas Currents'. The map shows the Brazilian current, but there is no evidence of the Agulhas current.
p.24 Discussing the recording and averaging of weather conditions, the author states that `When these values are mapped across the Earth, they reveal the large-scale average patterns of weather phenomena that span weeks, months, seasons or even years.' The word `even' suggests an element of surprise that such long periods can be encompassed, but surely this is a central part of what weather recording is all about?
On the same page, a paragraph is devoted to explaining that `There is no particular value that makes an area of low pressure `low'.......' On p 26, high pressure gets the same treatment. The word `relative', which does not appear, would have expressed this simple concept much more efficiently. It's as if the author is grappling with a new and unfamiliar subject.
pp.24 and 25 Maps are presented showing mean-sea-level pressure over both oceans and land masses. The text gives no indication as to what they mean when applied over land; for instance, is the mean-sea-level pressure in the Himalayas arrived at by some process of extrapolation? And what would be the purpose of such extrapolation?
p.25 Reference is made to the `extensive cold continents' without stating which ones. North America, Asia, Antarctica?
p.27 ` ..... across the intensely heated southern continents of South America, Southern Africa and Australasia.' Surely Southern Africa is not a continent but rather part of a continent?
And surely the editor should have spotted these:
p17. `.... from the extremely short ultraviolet to the very long waves that are used to for radio broadcasts.'
p.21 `.... this is the reason why, for example, that the storms that run across western Europe .......'
p22. The `Kuro Siwa' current in the text, `Kuro Siwo' on the map.
Having given up on the first 27 pages, I moved on to the section entitled `Explaining the weather'. On the first page, p.56, I read
`Broadly, the passage of a warm front brings warmer, moister air and a veering of the wind direction. This means that the wind shifts in a clockwise direction ...... from southeasterly to southwesterly [90 degrees] in the northern hemisphere; in the southern hemisphere, the wind shifts from northeasterly to southwesterly [180 degrees].'
In light of the book's shortcomings already noted, I'm left wondering if this is correct. Would a complete reversal of wind direction be referred to merely as a shift? And if the statement is correct, what is the reason for this radical difference between the northern and southern hemispheres?
At this point I gave up completely.