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Response of Australian Temperature Extremes to Climate Variability and Change

Regional Climate Research SectionNCAR Earth System Laboratory

NCAR is Sponsored by NSF and this work is partially supported by the Willis Research Network, the DOE Research Program to Secure Energy for

America and NSF EASM Grants 1048841 and 1048829

Greg Holland

Collaboration with Cindy Bruyere Mari Jones and Abby Jaye

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• Working Hypothesis: o Global temperature extremes change

slowly- if at all – under GWo Maxima from advection increase substantially.

• The Record Australian Summer 2013

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Summary

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Stations Used

Giles

Sydney

Mel

Alice

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In Situ and Advective Extremes

15 20 25 30 35 40 45 500

0.2

0.4

0.6

0.8

1

1.2Giles Jan 1957-2013Mel Jan 1857-2013

Maximum Temperature (oC)

Norm

alized

Fre

qu

en

cy

In Situ/Advective

In Situ

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Both Can Occur Together

Advective

In Situ

(Mari Jones)

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Seasonal: Desert In Situ Temperatures

• Extremes bumping up against the maximum possible• Skewed distribution develops

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Giles Maxima

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Climate Change: In Situ Temperatures

Variable, but marked increase in hot days and no change in extremes.

• Analysis Bdy Conditions, including SST, Interactive Land

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WRF Simulations

WRF Vs Observed Max TemperaturesAfter 17 days integration

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Hea

t Bui

ld U

p

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Diu

rnal

Var

iatio

n

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2xCO

2 Si

mul

ation

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Clim

ate

Chan

ge Im

pact

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Trend 1970-2011>35oC Maximum Temperature

(Bureau of Meteorology 2013)

In Situ Advective

• Global extreme temperatures change slowly, if at all, with GW

• For In Situ temperature extremes, PDF skews to more hot temperatures

• Advected temperature records increase substantially

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Summary