Extreme weather events

Question 1

important research areas

Answer 1

improving observational capability, extending the record of observations, improve diagnostic process studies, develop models, conducting integrated impact assessments

Question 2

reasons for increase in extreme events

Answer 2

climate change

Question 3

whats a hazard

Answer 3

process, phenomenon or human activity that may cause loss of life, injury, property damage, social/economic disruption or envtl degradation

Question 4

whats a risk

Answer 4

chance, high or low, that any hazard will actually cause somebody harm

Question 5

whats weather

Answer 5

reflects the conditions of the atmosphere over a short period of time

Question 6

whats climate

Answer 6

refers to the average weather/atmospheric patterns over an extended time period

Question 7

whats happened to the intensity and deadliness of cyclones across the atlantic

Answer 7

they’ve increased alot

Question 8

whats the palmer drought severity index (PDSI)

Answer 8

prominent index of drought and measures the cumulative deficit in surface land moisture by incorporating previous precipitation and estimates of moisture drawn into the atmosphere into a hydrological accounting system

Question 9

whats the trend of precipitation in USA

Answer 9

increased - concentrated inn heavy events, particularly in the northeast and midwest

Question 10

ACE index

Answer 10

accounts for combined strength and duration of tropical storms and hurricanes during a given season by computing theism of squares of the 6 hour maximum sustained surface winds in knots while the storm is above tropical storm intensity
-levinson 2005

Question 11

have amount and length of storms increased?

Answer 11

those lasting 2 days have not increased

those lasting less than 2 days have increased a lot - maybe due to better observations

Question 12

what else could wildfires be affected by

Answer 12

land management and regulatory decisions

people building homes at the wildland urban interface

Question 13

costs of weather variability

Answer 13

9 weather and climate disaster events with losses exceeding $1 billion each in USA

Question 14

overall impact

Answer 14

wet gets wetter, dry gets dryer

Question 15

what does disproportionate warming of the poles do

Answer 15

reduce meridional temp gradient, impacting speed and waviness of jet stream.
jet stream moves further north

Question 16

what happens to jet stream

Answer 16

moves further north
slows
becomes more wavy
more episodes of severe cold weather

Question 17

whats the most pronounced mode of coupled atmosphere-ocean variability

Answer 17

el nino

- largest source f climate variability in the instrumental record

Question 18

an atmosphere ocean coupling

Answer 18

Normally, the tropical Pacific Ocean features strong trade winds that blow from east to west - warm water piles up near Indonesia
These trade winds bring ocean water with them, which gets heated up by the sun. piles up in the western Pacific. The large warm pool of water near Indonesia causes the air above it to rise, creating rainfall. Meanwhile, back east along South America, frigid water deep down in the ocean gets pulled up closer to the surface — cooling the waters around Peru.
sea levels are about half a meter higher in Indonesia than they are in South America. Sea surface temperatures near Indonesia are also about 8°C (or 14.4°F) warmer than near Peru
- convective loop

Question 19

el nino

what is it and effects

Answer 19

pacific trade winds disrupted every few years.
- warm water near Indonesia sloshes back E
- thermocline starts sinking
- waters near Peru start warming
- less rain in sahel region of Africa so less triggering of African easterly waves (seeds for cyclones)
This all causes sea surface temperatures in the east and central Pacific to start rising and the trade winds to weaken further - positive feedback
el Nino associated with drier weather in places like Australia and Indonesia

Question 20

who is sir Gilbert walker

Answer 20

boomerang

pacific so vast - ENSO system is a major driving force in global climate

Question 21

whats la nina

Answer 21

cold and dry in california

Question 22

attribution

Answer 22

process f evaluating relative contributions of multiple causal factors to a change or event with assignment of statistical confidence

Question 23

2 classes of attribution

Answer 23

• those that rely on observational record to determine change in probability and magnitude
• those that use model simulations to compare the manifestation of an event in a world of human caused climate change and one without

Question 24

climate models can be ran several times with variations in:

Answer 24

• diff future warming scenarios
• diff models
• account for natural ‘random’ variability in earths system

Question 25

solution to each simulation giving slightly diff answer

Answer 25

run it enough and get a mean

Question 26

what do we look out for in events to see change

Answer 26

• frequency
• intensity
• duration
• timing

Question 27

winter of 2013/14 storm in UK

Answer 27

record rain and flooding. thames river valley was damaged - £1billion

Question 28

in the SE England whats the chance of exceeding the current rainfall record in at least one month in any winter

Answer 28

7%

Question 29

confidence in attribution results is strongest for extreme events that

Answer 29

• have long term record
• simulated adequately in climate models
• purely meteorological in nature and we understand the driving physical mechanisms

Question 30

are all the events purely meteorological?

Answer 30

no they have human components till

Question 31

are the impacts always the same

Answer 31

no, depends what intervention and mitigation occurs

many cities located near coast

Question 32

benefits of understanding links between cc and weather events

Answer 32

• prediction
• mitigation
• international corporation and investment
• insurance and risk transfer

Question 33

why can temp rise effect weather

Answer 33

• increase in evapotranspiration
• atmosphere hods 4% more water vapour now than 40yrs ago
• disproportionate warming of poles compared to equator
• changes in sea surface temp