Unit 3 Mini Case Studies Flashcards
Where are the highest temperatures over land in January?
Australia and Southern Africa
Where are the lowest temperatures over land in January?
Siberia and Greenland and the Canadian Arctic
Where are anomalies in annual temperature patterns?
Usually there is a decline in temperatures northwards from the Tropic of Capricorn but some anomalies are the Andes in South America and the effect of the cold ocean current off the coast of Namibia
Where are maximum temperatures in July?
In the Sahara, Near East, North India and South USA and Mexico. Areas in the Southern Hemisphere are cooler than in January
What is high pressure like over Antarctica?
Generally high pressure over the 3-4km high eastern plateau but the high pressure is reduced by altitude
What happens to the STHP belts over South Africa and Australia
In summer they are broken
What happens to high pressure over continental areas?
High pressure only occurs over ocean as discrete cells like the Azores and Pacific highs. Over continental areas like southwest USA, South Asia and the Sahara, major fluctuations occur
What happens to pressure in the Northern hemisphere and polar regions?
In N hemisphere there are strong winter low pressure zones over Icelandic and Oceanic areas but over Canada and Siberia there is high pressure due to the coldness of the land. In polar areas, pressure is quite high throughout the year especially in Antarctica due to the coldness of the land
Where does the ITCZ lie in July and August?
Well north of the equator over Africa, Asia and Central America before moving South into South America, Central Africa and Australia by January and February
2005 India monsoon
In 2005 a strong monsoon devastated west India. It first hit Gujarat. Over 100 died. It then hit Maharashtra. Flooding here killed over 1000. On july 26th 2005 Mumbai received 39.1 inches of rain
What air masses is the UK affected by?
It sits on the boundary between warm tropical air to the south and cold polar and arctic air to the north. It is at the edge of the European continent and so is influenced by both dry and continental air and humid maritime air. This means the UK is a battleground between many air masses fighting to influence the weather
The UK and Rossby waves
In winter the jet stream is further south, directly overhead. In the summer it is often north of the UK. This shift influences weather. In summer a more northerly jet stream allows Tm and Tc air to move north over the UK bringing warmer and maybe drier air and settled, sunny conditions. The polar front boundary between polar and tropical air is north of the UK. In winter this boundary sits over the UK allowing Pm, Pmr and Am air bringing cooler, wetter conditions and often strong winds
Depressions tracks in the UK
UK weather is often dominated by low pressure, cyclonic weather systems (depressions). Wet and windy weather comes with these as they move over the UK from west to east
The UK ad Rossby waves, Omega blocks and Arctic blasts, polar outbreak and arctic plumes
Norway
Iceland
USA
The Rossby wave meander prevents Pm and air depressions passing over the UK and directs them north to Iceland and Norway. If the Omega block sits to the west of the UK it can allow Am air to flood down from the north or Pc air to move in from the east
In an Arctic blast, polar outbreak or arctic plume, deep southward meanders develop in the jet stream allowing areas of cold polar air to extend south over the UK and Great Lakes of the USA. This can bring very cold weather and snowfall. Can persist for weeks. In 2009-2010 and 2010-2011 the UK experienced this. Large pockets of cold air can become detached and sink as far as Oklahoma USA
Negative NAO phases and the UK, North America, Europe, France, Spain and Italy
Cold outbreaks and Arctic blasts occurs over the UK and North America
The polar jet stream loops south into southern Europe bringing depressions to France, Spain and Italy
