Unit 3 Mini Case Studies Flashcards
the normal stuff is hard enough no
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
Were the 2009-2011 Uk winters unusual or normal?
Unusual - sign of global warming
Impacts of 2015-2016 El Nino
Short term changes in weather conditions affecting fisheries and agriculture, impacting food security and health
Usually heavy rain in SE South America, E Africa and SE USA and reduced rain over Indonesia, Australia, S Africa and N South America. Makes vulnerable to forest fired
Burning of trees increases CO2 and reduces air quality
Features of 2015-2016 El Nino
Subsequent La Nina was weaker than expected
Warm water hovered around the equator of the central pacific in 2014
Early building peaking in January 2016
Covered a large area to 21N (Haiwai)
Warm water reduced temperature gradient and the trade wind strength
The Pacific Decadal Oscillation is a large long term pattern of sea temperature changes (5-20 years) impacting ENSO. Enhances El Nino and La Nina. Lasted for 3 years since 2014, strengthening El Nino
Cyclone Winston
More tropical cyclones occur in Pacific due to vertical wind shear
The 2015-2016 cyclone caused 50 deaths and damages were $1.405 billion, reaching cat 5 on the Saffir-Simpson scale
Occurred on February 12 2016, the system was 2C higher than average. Approached Fiji from the East. Reached cat 5 on Feb 19 and 20 also. Costliest to ever hit the South Pacific Basin
USA El Nino Impacts
Usually warmer NW and colder SE
Atmospheric rivers cause extreme flooding
In 1997-1998 rain caused 17 deaths and $883 million in damages across California
40 out of 58 countries were declared disaster zones
30 inches of rain in Southern California
Can restore water supplies leading to wasted unnecessary preparations
Ethiopia drought
Causes 80% of the harvest to fail and 22 million were affected
Malnutrition and migration rose
Risk of insect diseases due to heavy rain, rift valley fever and cholera
Disease monitoring, vaccines, promotion of hygiene and access to medical services are increasing resilience
Paraguay floods
100000 evacuated due to floods in Asuncion and borders or Argentina and Uruguay
Schools and military buildings used as shelters
Looting
60 million affect worldwide by 2015-2016 El Nino
Monitoring, predicting and adapting is needed
2017 El Nino
February and March 2017 Peru and Colombia has major rainfall. 94 died and 700000 homeless in Peru. $3.1 billion cost to the economy in damages which is 1.6% of their GDP
Mudslide in Colombia killed 450
Waters off the coast of Peru are warmer than normal suggesting El Nino
More severe may occur later
Climate change and El Nino
2016 was hottest year an increase of 0.12C
Sea rose by 7mm due to thermal expansion
For 12 consecutive months, temperatures hit new records
In 2015-2016 El Nino:
-warmest winter in 48 states
-wettest December in 48 states
-highest snowfall from 1 storm in Pennsylvania, Newark and NY
Global warming could produce stronger or more frequent El Ninos involving changes in the worlds heat balance
Sea ice in the Arctic and Antarctic
Decreased in Arctic, increased in Antarctic
Melting of Arctic ice and Thawing of permafrost
Melting of Arctic ice could trigger changes in ocean currents in North Atlantic
Thawing of permafrost in Northern Russia and Canada could release CO2 and methane, accelerating global warming
Crops due to global warming
Farms in Canada and Northern Europe may benefit from warmer conditions. May be a drop in crop yields in Africa of 35%
Chinas power stations
China is building 1 coal-fired power stations every week because not doing so would be harmful. Some countries feel that there is little point in cutting back on fossil fuel use while India and China continue to build lits of fossil fuel powered stations
Effects of increased global temperature change
Rise in sea levels in Netherlands, Egypt and Bangladesh
Decline in USA’s green belt
Rise in Canadas growing season
Reduced rainfall over USA, Southern Europe and CIS causing widespread drought
35% drop in crop yields across Africa and Middle east if temps rise by 3C
60 million more Africans could be exposed to malaria if temps rise by 2C
Positive effects of climate change in UK
Increase in timber yields (up to 25% by 2050) especially in the North (small fall in South)
Northward shift of farming zones by about 200-300km per 1C of warming or 50-80km per decade will improve some forms of agriculture especially pastoral farming in North west
Enhanced tourism potential and recreation as a result of increased temperatures and reduced precipitation in the summer especially in the south
Negative effects of climate change in the UK
Increased damage effects of increased storminess, flooding and erosion on natural and human resources and human resource assets in coastal areas
Increase in animal species especially insects as a result of northward migration from the continents and a small fall in the number of plant species due to the loss of northern and mountain types
Increase in soil drought, soil erosion and shrinkage of clay soils
Wind farms in UK
In the UK the government has encouraged wind farms but these are expensive, regarded as ugly and only efficient when the wind is blowing
