Geoscience Reference
In-Depth Information
1
WesternClimateChange
Philip W. Mote and Kelly T. Redmond
CONTENTS
Introduction................................................................................................................ 3
Observed.Climate.Variability.and.Change.in.the.Western.United.States................... 5
Temperature.Variability.and.Change...................................................................... 6
Dependence.of.Trends.on.Elevation...................................................................... 6
Variability.and.Changes.in.Precipitation............................................................... 8
Hydrologic.Responses.to.Changes.in.Temperature............................................... 9
Global.Teleconnections........................................................................................ 10
Detection.and.Attribution..................................................................................... 13
Modeled.Future.Change........................................................................................... 14
Spatial.Patterns.of.Change................................................................................... 15
Temporal.Change.of.Western.Mean.Temperature.and.Precipitation................... 15
Statistical.Properties.of.Change........................................................................... 18
Changes.in.Variability.......................................................................................... 18
Summary................................................................................................................... 20
Acknowledgments.................................................................................................... 20
References................................................................................................................ 21
INTRODUCTION
Earth's.global.climate.is.determined.by.a.balance.between.absorbed.solar.radiation.
and.emitted.infrared.radiation..The.amount.of.absorbed.solar.radiation.in.turn.is.
determined.by.the.sun's.emissions.and.the.Earth's.relectivity,.primarily.the.frac-
tion. of. the. planet. covered. by. clouds. and. ice.. Infrared. emissions. come. predomi-
nantly.from.gases.in.the.atmosphere:.water.vapor,.carbon.dioxide,.methane,.nitrous.
oxide,.and.many.more..The.atmosphere.also.emits.energy.toward.Earth,.keeping.
it.warmer.than.it.would.otherwise.be,.and.providing.roughly.twice.the.energy.as.
is.provided.by.absorbed.solar.energy.(e.g.,.Trenberth.et.al..2009)..At.the.surface,.
the.absorbed.solar.energy.plus.atmospheric.infrared.energy.is.balanced.globally.
by.radiation.of.infrared.radiation.plus.latent.and.sensible.heat.lux.(Trenberth.et.al..
2009),.all.of.which.are.mediated.by.vegetation,.especially.moisture.luxes..In.turn,.
the.expression.of.global.climate.and.of.atmospheric.luctuations.helps.determine.
the.distribution,.health,.function,.reproductive.rates,.and.much.more,.of.organisms.
on.the.landscape.
3
