Cryosphere Lecture 7

Get Revising

Created by: P GREENWOOD
Created on: 03-01-17 20:58

Impact of climate on ice

Direct impacts - gain/loss of mass, Indirect impacts (surface meltwater)

1 of 14

Ocean control on major ice sheet extent

Driven by changes in atmosphere / wind?

2 of 14

Ice sheet change (climate driven) impact on ocean circulation

=> Impact of ice on climate through ocean circulation change

3 of 14

Demonstrates sensitivity of one aspect of the climate system to the other

=> Dynamic system!

4 of 14

RCP2.6

V.Low baseline And heavy mitigation, Medium (cropland and pasture), Medium-low

5 of 14

RCP4.5

V.low baseline, Or heavy mitigation, V.Low (cropland and pasture), Medium

6 of 14

RCP6

Med. Baseline, Or some mitigation, Medium cropland, very low pasture, Medium

7 of 14

RCP8.5

High Baseline, Medium (cropland and pasture), Medium-high

8 of 14

The future? – Greenland Ice Sheet

Increasingly negative surface mass balance (mass loss) Dynamic (marine driven) retreat ongoing Up to ~ 0.2 m sea level equivalent over the next decade

9 of 14

The future? – Antarctic Ice Sheet

Increasingly positive surface mass balance Potential for large dynamically driven mass loss Up to ~ 0.2 m sea level equivalent over the next decade

10 of 14

Uncertainty in climate forcing

RCPs are “scenarios” rather than “predictions”

11 of 14

Natural variability / internal regulation

Marine driven thinning a function of NAO / SO? Zwally effect Lower winter velocity offsets summer increase? (Sole et al., 2013) Marine ice sheet instability Ice stream thermal feedback mechanism might lead to a velocity decrease? Changes in geotherma

12 of 14

Uncertainty in models

Process representation Parameter uncertainty Input data uncertainty/ lack of data

13 of 14

The cryosphere is complex & difficult to predict!

We don’t fully understand all the processes going on as yet Danger of extrapolating long term trends from short term data Important that we do understand the cryosphere more fully!

14 of 14

Other cards in this set

Card 2

Front

Ocean control on major ice sheet extent

Back

Driven by changes in atmosphere / wind?

Card 3

Front

Ice sheet change (climate driven) impact on ocean circulation

Back

Card 4

Front

Demonstrates sensitivity of one aspect of the climate system to the other

Back

Card 5

Front

RCP2.6

Back

View more cards

Get Revising

Cryosphere Lecture 7