Evidencias Atmosféricas del Cambio Climático en el Pacifico Sur Oriental

René D. Garreaud

Departamento de Geofísica Universidad de Chile

Centro del Clima y Resiliencia

Reunión conformación grupo expertos nacionales en Cambio Climático del Sistema Marino

Valparaiso, 21-Dic-2018

120°W 90°W 60°W 30°W

60°S

30°S

0°S

S. Atlantic Anticyclone

Midlatitude Storm track

Continental Low Level Jet

SE Pacific Anticyclone

Midlat. Precip.

Tropical rainfall

SCu & Cold SST

The big picture v qt

LLJ

1000 m ASL

Is t

he r

eg

ion

al co

oli

ng

of

the

Hu

mb

old

t E

BU

S a

lread

y t

akin

g p

lace?

Offshore

Coast

Inland

West Andes

East Andes

Falvey & Garreaud 2009

Is t

he r

eg

ion

al co

oli

ng

of

the

Hu

mb

old

t E

BU

S a

lread

y t

akin

g p

lace?

Aguirre et al. 2009

Vwind & SST trends (1979-2015)

Is the regional cooling of the

Humboldt EBUS already taking place?

Over the Pacifc SST trend looks very similar to the PDV patter

2006-1979

Falvey & Garreaud 2009

Is t

he r

eg

ion

al co

oli

ng

of

the

Hu

mb

old

t E

BU

S a

lread

y t

akin

g p

lace?

Observed (ERA) PDO-Congruent

AMIP (Ocean forced) Hist (CC)

SLP trends (1979-2015)

Aguirre et al. 2009

Central Chile Southern Chile Annual rainfall trends

(1960-2016)

Precipitation trends over land

Boisier et al. 2018, Elementa

Frequency Area Chlorophyll Discharge Nitrate Phosphate

Plume River Load

43

45

55

61

61

75

45

96

39

46

45

46

104

59

21

41

51

65

55

62

55

70

100

83

55

88

86

96

102

102

Numbers and colored areas indicate the mega drought (2010-2014) mean values of selected variables as a percentage of the past decade (2000-2009) averages for five rivers in central Chile. Maipo, Mataquito and Maule river have P and Ni data until 2011 only.

39°S

31°S

Massoti et al. 2018, Frontiers

Impact of Mega drought in coastal zone

Precipitation trends 1960-2005: Attribution Both O3 depletion and GHG increase, but O3

effect dominates in summer

Boisier et al. 2018, Elementa

What about

Extreme Events?

Puelo summer

Puerto Montt annual

Trend and Variability

Leon-Muñoz et al. 2018, Sci. Reports

Greening

Drying

No change

-90 0 +90 %

Chiloe Island

Aysen River

Coyhaique

NW

Pat

ago

nia

Puerto Montt

(a) Precipitation anomalies (b) Enhanced Vegetation Index anomalies (a) Streamflow anomalies

The awful 2016

El Niño! Natural….

SAM! Antrophogenic

r = -0.2

Large scale conditions JFMA 2016

Garreaud 2018, Sci. Res.

Mortality

Uptake

Encystment

Grazing Advecction Transport

Turbulence Upwelling

Harvesting Consumption

Competition

Dormancy

Alexandrium Catenella

Other Algae communities

(Diatoms)

Bloom Zooplankton

Shell fish

Pelagic fish

Solar Radiation

Photosynthesis

Consumption Filtering

SXT accumulation

Cell growth

Physical processes

Biological processes Macro algae

Cyst

Zygote

© RGarreaud / DGF-UCh + CR2

Nutrients (P,N,Si)

Solar Radiation

Heat Fresh Water Momentum

Atmosphere/Land Boundary Conditions

Nutrient Fluxes (N, P, Si)

Upwelling

Aquaculture

Excystment Sedimentation Deep

Water

Poisoning

Fluxes

Upwelling

Ocean state:

• Temperature • Stratification ((z)) • Vertical velocity • Currents • pH

Uptake

Advecction Transport

Turbulence Upwelling

Alexandrium Catenella

Bloom

Solar Radiation

Photosynthesis

Cell growth

Physical processes

Biological processes

© RGarreaud / DGF-UCh + CR2

Nutrients (P,N,Si)

Solar Radiation

Fresh Water

Atmosphere/Land Boundary Conditions

Deep Water

Fluxes

Ocean state:

• Temperature • Stratification ((z)) • Vertical velocity • Currents • pH

The awful 2016

Balance De Masa

GCMs (more than 40)

Socio-economic development pathways

How much CO2 will be emitted in the future ?

Climate Scenarios

+300

0

-300

°C mm/yr +4

0

-4

+1

0

-1

PSU

(a) Sea Surface Temperature (b) Precipitation (c) Surface salinity

Projected changes End of century under heavy emission scenarios

Least warming

Marked drying

Garreaud 2019, submitted to JFD

Southern SA Climate Change Projections Towards the end of century under A2 (RCP8.5)

Estudio DGF/UCh-CONAMA 2007 empleando PRECIS

Environmental extremes and change Social tensions

Local activities Climate variability Climate change

9 de Junio 2016 - Posición: 36.4°S 72.9°W 5 millas náuticas frente a la desembocadura

del río Itata - Región del Bio Bio

© Cesar Hormazabal

Medir, medir, medir…

Belmar et al. 2019???