Science and Impacts Flashcards Preview

Climate Change > Science and Impacts > Flashcards

Flashcards in Science and Impacts Deck (38)
Loading flashcards...
1

What is climate?

The average weather (its mean and variability) over a specific time period

2

What is Climate Change?

The change in climate with time due to natural variability or human activity (IPCC)

3

Examples of observed climate variables ...

Temperature, Precipitation, humidity, cloud cover, snow cover, sea-ice thickness and extend, natural modes (ENSO, NAO)

4

How are anomalies used?

To identify positive and negative excursions from a start/end point or around a long-term trend

5

Summary of surface temperature changes

In the 20th century there has been a consistent large-scale warming of the land and ocean surface

6

Which time period saw the greatest warming?

the last 30-50 years (IPCC, 2013)

7

When did surface observations of temperature begin?

1880 - use of thermometers

8

What do radiosondes do?

Measure variables (e.g. temperature, relative humidity, wind speed) at discrete altitudes, transmits to a computer by radio

9

How do we measure upper air temperature?

Radiosondes and Satellite

10

What do satellites do?

Measures radiation emitted by earth to get temperature and moisture readings

11

Why are satellites useful?

Broad coverage ... can make up for northern hemisphere bias of surface readings

12

Upper air temperature trends, relative to the 1981-2010 mean ...

-lower troposphere has warmed globally
-lower stratosphere has cooled

13

What impact do volcanic eruptions have on the troposphere and stratosphere?

Cools the troposphere and heats the stratosphere

14

How have Arctic temperature trends changed over time?

Average arctic temperatures have increased at almost twice the global average in the past 100 years

15

What happened to sea ice during the global warming 'hiatus'?

Arctic sea ice continued to decrease

16

How have glaciers changed worldwide? The Alps?

Glacier retreat worldwide
-Alps: 500m decrease in length since 1950

17

What is the North Atlantic Oscillation (NAO)?

A mature of circulation patterns in the northern hemisphere

18

What does a positive NAO imply?

Warmer European conditions

19

How have positive NAO indices changed?

Greater occurrence from 1980s-1990s

20

Climate extremes in the last 50 years ...

-more extremely warm days and nights in a year
-fewer extremely cold days and nights in a year
-fewer frost days in mid-latitudes

21

What causes sea-level rise?

-Thermal expansion
-Ice cap melt
-Isostatic rebound (since ice sheet melt, land recovering, can move up and down)

22

Which is more straight forward to model-temperature or precipitation?

Temperature

23

What is the precipitation trend in the higher latitudes?

More precipitation falling as rain, rather than snow

24

What different indicators do we have to know the world has warmed?

(IPCC AR5)
-Decrease in ... glacier volume, snow cover, sea ice area
-Increase in ... air temperature, water vapour, land temperature, ocean heat content, sea surface temperature

25

When was the European heat wave?

2003 ... probably the hottest summer in Europe for 500 years

26

When did European tide gauge measurements begin?

As early as 1670

27

When did southern hemisphere tide gauge measurements begin?

Late 19th century

28

What is the issue with tide gauges?

Large gaps in time and geographical spread

29

When did NASA and NOAA start tracking global ocean topography?

1992

30

What does satellite altimetry do?

Capture variations in sea level across most of the planets oceans every 10 days