Sunday, 6 April 2008
The theme this year is Explore Your World...
"We want you to carry out a project that involves you exploring the world around you. The project must be completed somewhere in the UK, and must involve you getting out into the real world and making a geographical investigation – it could be a survey of your local streets or a study of a stretch of coastline. We want you to bring geography alive and show how it helps us to understand the world in which we live. Your entry can take whatever form you think is most appropriate – be it a written report, a short video film, a photographic essay, an annotated map, an audio file or a mix of all of these. The important thing is that you get out of the classroom, away from your computer screen and into the outside world."
Great prizes to be won! Full details here... Get exploring!!
The idea is that you choose a disaster scenario - one of which is a hurricane in the Caribbean - and then you are responsible for making decisions about how to protect the community from the inevitable disaster...
Leave a comment and tell us how you get on!
Saturday, 5 April 2008
- hurricanes in the USA and Caribbean
- cyclones in India, Bangladesh and other parts of southern Asia
- typhoons in Asia Pacific (esp. Japan)
- willy-willies in Australia
...are large storms (300-400 miles across, and 5-6 miles high) rotating round areas of extreme low pressure.
They occur between 5o and 20o N and S of the equator (Coriolis force nearer to the equator is too weak to cause the storm to rotate) where sea surface temperatures are 27oC or greater.
There's a nice summary from the Met Office here, an animated guide from the BBC, and you might like to have a look at Towers in the Tempest which looks at how "hot towers" cause hurricanes to intensify.
Plenty of info also from the National Weather Service and the National Hurricane Center.
As well as understanding how TRSs form, you need to know about the effects they have, and how these are likely to be different in countries/regions at different levels of development.
hit the south-eastern USA in August 2005. It is believed to have killed about 1500 people, and with the cost of damage estimated to have been about $300 billion, was the most costly disaster to hit the USA.
The Met Office have put together a very good case study page (click on the satellite image of Katrina above) which looks at the physical impacts, human impacts and responses, and also has a set of activities for you to have a go at.
There are lots and lots of other sources of information available - one of the best is probably the BBC's In Depth Guide and it's well worth spending some time investigating this properly.
This "Storm Viewer" shows the track of Hurricane Katrina, but also shows you how the pressure, wind speeds and precipitation changed with the development of the hurricane. Various similar animations of other hurricanes here.
Cyclone Sidr next...
- associated with mid-latitude depressions where there is a steep pressure gradient
- tend to cause disruption to power supplies and transport
Great Storm of 1987...
Michael Fish's infamous "hurricane" weather report...
(Remember though, that, although there were hurricane force winds, this wasn't actually a hurricane!)
Friday, 4 April 2008
For those of you who missed the discussion at the end of this afternoon's lesson, we also talked about getting together to go through some questions, etc. - my frees are p4 and 5 on Mondays, p4 on Thursdays, and p3 and 4 on Fridays. If we can all agree one of these times, we will - if not we'll organise a couple of after-school sessions (any day except Monday)... Let me know if you want to come along and if so which time(s) would be best.
There are some interesting satellite image sequences on the Met Office website - looking at these, together with the pressure charts and keeping an eye on what the weather's actually like will help you to make more sense of the work we've done over the past couple of weeks.
Wednesday, 2 April 2008
Appear very clear on satellite images... On weather maps, closed isobars which are widely spaced and with a gentle pressure gradient between the centre and edge of the anticyclone... therefore, gentle winds blowing out from the centre (clockwise in N. Hemisphere).
- Lack of cloud = direct insolation = rapid heating... therefore hot (and dry) weather.
- Lack of cloud = rapid cooling at night... relatively cold ground may cause formation of dew and early morning mist.
- Possibility of sea frets along east coast.
- *Convectional rainstorms may occur in the afternoon.
- Lack of cloud BUT sun at a low angle in the sky so inefficient heating = remains cold all day.
- Rapid cooling at night = formation of mist, radiation fog and frost.
- Temperature inversions may mean that air pollution is trapped.
Remember, stable and slow-moving systems that may stay in more or less the same place for several weeks. Blocking anticyclones over the British Isles will cause depressions coming in from the Atlantic to move northwards and bypass us.