Air Quality Forecast in Santiago, Chile Pablo Ulriksen and Manuel Merino Centro Nacional del Medio Ambiente Universidad de Chile GURME Air Quality Forecasting Workshop Santiago, Chile October 2003

Air Pollution in Santiago Geographical location Meteorological conditions Urban population and activities

Geographical location

Santiago City Area

Climate Santiago *

Anticyclon subsidence inversion Fig. from R. Sanguineti, CONAMA

Surface Wind, Winter afternoon

Surface wind, Winter night LPLA MALL PIRQ QUIL LREI EMAN PAIC POLP LCAÑ LTIL LPIN CODI MPIN PAIN 1 m/s Viento promedio Mensual Julio 1999, 03:00 a 05:45 Hrs

Santiago City Statistics Metropolitan Region Population (40% Country) Santiago City Population Houses Daily trips~ 8.8 million/day Vehicles~ (56 % catalytic)

Santiago City Statistics Labor Force Activities, Santiago Metropolitan Region, 2001 Agriculture3.6 % Industry17.2 % Construction6.8 % Transport8.1 % Commerce21.2 % Finantial Services12.0 % Social and Professional Services30.2 % Mining0.4 % Elec, Water, Gas0.5 %

Air Quality Standards Exceedance during Days TSPCO 1 h O3O3 PM10CO 8 h Air Quality in Santiago City

Maximum AQI values during 1995 Air Quality Index PM10O3COSO Air Quality in Santiago City

PM10 Monthly Averages, Santiago, Chile, (Dicothomous Samplers) Year PM10 (ug/m3)

Air Quality Standard Level 1 Alert Level 2 Pre-Emergency

PM10 Air Quality Standard and Episode Levels PM10 Air Quality Standard (24 h period): 150 ug/m3N Episode Levels related to PM10 24h concentrations: Level 1 (Alert) ug/m3 Level 2 (Pre-Emergency) ug/m3 Nivel 3 (Emergency)330 ug/m3 or higher

Definición de Índice de Calidad del Aire para Partículas ICAP y Niveles que definen condiciones de Episodio Concentración MP10 (  g/m 3 ) ICAP Preemergencia Emergencia ( > 330  g/m 3 ) Alerta Norma de Calidad (150  g/m 3 ) Bueno a Regular

Meteorological Conditions Related to PM10 Episodes (J. Rutllant and R. Garreaud, 1995) Episodes Type A(Anticyclonic conditions, Coastal Low) Episodes Type BPF(Pre-Frontal Conditions)

Episodio Tipo A Mapa de 500 hPa

Episodio Tipo A Mapa de Superficie y Espesor hPa

Radiosondeo Quintero 17 Mayo hora local-A

Temperatura y H.R. en Lo Prado

Episodio Tipo BPF Mapa de 500 hPa

Episodio Tipo BPF Mapa de superficie y Espesor hPa

Quintero 08 Abril hora local- BPF

Ocurrencia de episodios Tipo A y BPF (Abril-Sep )

Condiciones Meteorológicas y MP10 Episodios Alta del Pacífico Inestabilidad post-frontal Actividad frontal PM-10 PROMEDIO Episodios Tipos A y BPF Alta del Pacífico Inestabilidad post-frontal Actividad frontal

Temperatura y H.R. en Lo Prado

Episodio Pudahuel 26 Junio 2001

Meteorological Index (PMCA) Air Pollution Meteorological Potential (PMCA) related to PM10 in Santiago (Represent an inverse of Ventilation factor) 5 Index Classes: 1 Low 2 Low to Medium 3 Medium 4 Medium to High 5 High Each Index Class is associated to one or more synoptic and mesoscale configurations Upper air variables ranges associated to each Index Class. Meteorological conditions follow up and analysis support expert forecast.

Meteorological Index Classes Class 1 Low Active Frontal Systems Intense Instability Class 2 Low to Medium Frontal Systems Instability Intense Humid Air Advection Segregated Cold Lows Class 3 Medium Anticyclone Conditions Light Humid Air Advection Class 4 Medium to High Type A Episode Type BPF Episode Medium Zonal Circulation Index Class 5 High Intense Type A Episode Intense Type BPF Episode Low Zonal Circulation Index Episode Conditions

Meteorological Index Classes Objective Classification Rules based on selected upper air forecasted variables

Daily Meteorological Index (PMCA) and PM10 time series

Air Quality Forecasting System for Santiago Forecast Requirements: Next day PM10 maximum 24 h value estimated at each monitoring station Forecast Accuracy > 65% at each monitoring station Independent expert validation Operational considerations: –Report episode levels not forecasted –Report changes in meteorological conditions that affect episode declarations –Report monitor stations perturbations that affect representativity

Air Quality Forecasting System for Santiago CENMA Air Quality Forecast Program: Use all the information and forecast tools available Operational use of forecast tested methods Final forecast decision by expert meteorologist Assure timely report deliver 2 persons (at least) dedicated every day, 7 days per week Permanent interaction with counterparts Permanent internal evaluation of analysis and forecast results Search Expert Evaluation and Recommendations

Air Quality Forecasting System for Santiago Conceptual Squeme Meteorological Conditions Synoptic and Mesoscale Meteorological Conditions Basin and Urban Scale Air Quality Emissions Meteorological Conditions Synoptic and Mesoscale Meteorological Conditions Basin and Urban Scale Air Quality Emissions Meteorological Index (PMCA) Present (Observed) Conditions Future (Forecast) Conditions

Air Quality Forecasting System for Santiago Data Sources

Air Quality Forecasting System for Santiago Meteorological Conditions Synoptic and Mesoscale Meteorological Conditions Basin and Urban Scale Air Quality Emissions Numerical Weather Forecast Models: NCEP (AVN), NOGAPS, ECMRF ETA (CPTEC Brasil), MM5 (U.Chile) CENMA Local Scale Meteorological Forecast (Meteorological Index, PMCA) Statistical Model (J. Cassmassi) Future (Forecast) Conditions Day of Week Air Quality Variation Data Sources

Regional Meteorological Network supporting Air Quality Forecast

Continuous monitoring: PM10 CO SO2 NOx O3 HC Meteorology Air Quality Monitoring Network in Santiago (MACAM2, 1997 )

Air Quality Forecast Model PM10 Forecast Model for Santiago Developed by J. Cassmassi (SCAQMD, California) Statistical relationships obtained by Multilinear Regression, PM10 maximum 24h values estimated for each monitoring station, one day in advance. Variables: –Observed: upper air meteorology, PM10 concentrations, week variation of PM10 (subrogate for emission variations) –Forecast and observed: Meteorological Conditions Index (PMCA) Data period: –Model Development: , April – Sep –Model Validation: 1999, April – Sep Independent evaluation: H. Fuenzalida, U. de Chile

Meteorological Index Forecast Evaluation Air Quality Forecast Evaluation

Air Quality Forecast Model Evaluation General agreement of observed and predicted values Over–prediction of Episode Level 1 Alert (False Alerts)

Air Quality Forecast Evaluation PM10 Observed and Forecast Values, March-Sep 2002

Air Quality Forecast Results PM10 Mean Concentration Increase last years

Air Quality Forecast Results PM10 Episode days Increase last years

Discussion Meteorology Index Forecast shows good perfomance Posible improvements: Refined NWP models for this Region Continue meteorology - air quality relationships analysis Air Quality Forecast: Adjust statistical model to air quality scenario changes Test other approaches (MOS, neural network, pattern classification,...?) Study Santiago North West Sector, where highest PM10 levels are observed.