Atmospheric Sciences at DGF – U. Chile (Santiago) - Departamento ...

Atmospheric Sciences at DGF – U. Chile (Santiago) - Departamento ...

Climate change in theSubtropical Andes (20-40ºS)René D. GarreaudDepartamento de GeofísicaUniversidad de ChileFirst ACCION Meeting, 2-3 Feb 2012

Atmospheric Sciences at DGF U. Chile (Santiago)•Laura Gallardo (Atmos. Chemistry)•Maisa Rojas (Climate dynamics and Paleoclimate)•Roberto Rondanelli (Climate Dynamics)•Ricardo Muñoz (Micro-meteorology)•René Garreaud (Climate dynamics, weather)•José Rutllant (Part time, weather, climate)•Patricio Aceituno (PT, Climate)•Humberto Fuenzalida (PT, Climate)•Mark Falvey (Modeling)•Rainer Schmitz (Air quality)•Dave Rahn (coastal Meteorology)•Max Viale (Mountain Meteorology)•∼10 M.Sc. Students (Claudio Bravo….)Our Tools / Methods•Regional Climate Modeling•Reanalysis & Satellite data analysis•In-situ observations (Sfc. And upper-air)•UAV and Instrumented aircraft• Hydro meteorogical modeling (snow & glaciers)

The big picture0°SContinentalLow Level JetS. AtlanticAnticyclone30°SSE PacificAnticycloneMidlat. Precip.Tropical rainfallSCu & Cold SSTMidlatitudeStorm track60°S120°W90°W 60°W 30°W

Zonal wind just upstream of the Andes (over the SE Pacific)

Never forget: Interannual / Interdecadal VariabilityInterannual Precipitation Variability (UdW data)

Never forget: Interannual / Interdecadal VariabilityP and SAT projected on ENSO IndexGarreaud et al. 2009

Geographical setting and global contextSAMPDO

Tendencias observadas (últimos 30 años): Temperatura

EastAndesObserved trends (last 50 years): SATWestAndesinlandcoastoffshoreFalvey & Garreaud 2008

Tendencias observadas (últimos 30 años): TemperaturaEnfriamientoCalentamientoFalvey & Garreaud 2008

How are the models doing?Not good but no so bad..∂T/∂tcentral Andes∂T/∂toff Central Chile

Precipitation Changes….warming, drying southmm/10 años150100500-50TENDENCIA DE LA PRECIPITACIONANUAL - 1950-2000• Rainy climate• MAP ∼ 1000-3000 mm• σ(IA)/MAP ∼ 0.1• Weak ENSO Impact• Significant drying trend-100-150-2003032Ref.: Quintana, 20043334353738Latitud Sur3940424553• Semiarid climate• MAP ∼ 30-500 mm• σ(IA)/MAP ∼ 0.3 0.5• Strong ENSO Impact• No significant trend

Multimodel precipitation and surfacetemperature Changes (A2-BL)© IPCC 2007: WG1-AR4 (2007)

Regional Climate Simulations at DGF-UCh (Rojas et al.)All outpus available via DODs: Chile Domain:PRECIS-Altiplano25 km hor res.WRF-ChileCentral15 km hor.res.Forced by HadCMBL (1960-1990)A2 (2070-200)B2 (2070-2100)Forced by ERABL (1958-2002)PRECIS-CONAMA25 km hor. Res.Forced by ECHAMA1b (1970-2080)

Differences A2(2100-2070) BL(1960-1990)Obtained with a regional climate model (PRECIS) forced by HadCM3 / A2Temperatura Superficial (SAT)Precipitación (P)-1° 0° 1° 2° 3° 4° 5° CPRECIS-DGF-UCH-50 0 +50 mm/mes

PRECIS-DGFAcomplamiento con modelos hidrológicos.

PRECIS-DGF Acomplamiento con modelos hidrológicos.

2006 186 2006 2962006 339En el producto en lapagina web, seestablece un pixelcon nieve si su valoresta entre 30 y 100

MODIS-derived Seasonal Snow Cover in Subtropical Andes (2001-now)

5000Snow depth at Lagunitas [cm]Inter-stormAblationSnD MaxAug. 20SnD = 0 fromSep. 25 onwards450040003500300025002000Snow line height [m ASL]Julian day [days since 01-01-2008](*) Snow line height from MODIS product at Aconcagua en Chacabuquito

MODIS-Snow line height at Maipo en el ManzanoWinter (MJJAS) precipitation at Quinta NormalNov. 30 ± 5 daysSep. 30 ± 5 days

Maipo en el Manzano01-07-2009 al 01-06-20Caudal medio diario [m3/s]Amplitud diaria de Q (max-min)Fracción nivalm 3 /s50250Q− Qmax minQ med≈ 0.15Q− Qmax minQ med≈ 0.25

Take home messages* Climate change superimposed on climate variability.* Climate data in the last 30-years marginally enough tovalidate GCM/RCM along the Andes. Main problem: lackof high-altitude stations, lack of metadata.* DGF-UCh offers to ACCION and other programs itsexpertise in Andean Climate, regional climate simulationsand hydromet modeling (hopefully for a collaborativework). No much actual data to offer but it couldimprove.

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