1. SOA vs POA in the Amazon: Current model estimates and predicted change Colette L. Heald heald@atmos.colostate.edu Aerosols in the Amazon Workshop February 18, 2008

2. SOUTH AMERICA DOMINATES GLOBAL SOA PRODUCTION (IN CURRENT MODELS!) Large contribution from South America driven by simulated isoprene emission in the Amazon: 1.How accurate are the emission factors for the Amazon? 2.How accurate are predicted changes in biogenic emissions? 3.Is SOA formation more efficient over the Amazon (low NOx)? 2100 (A1B) Emissions and Climate Simulated using NCAR CAM/CLM [Heald et al., JGR in press]

3. BIOGENIC EMISSIONS IN SOUTH AMERICA Simulated in NCAR CLM model for year 2000 (annual mean), based on MEGAN v2 algorithms. ISOPRENE: 32 % of global total MONOTERPENES: 16% of global total

4. ANNUAL MEAN CONCENTRATIONS IN 2000 Large seasonality, but generally in phase with peak in dry season Simulated using NCAR CAM/CLM

5. EMISSION/PRODUCTION CHANGES PREDICTED FOR 2100 SOA 24.3 POA 45.0 SOA 30.2 (+24%) POA 72.0 (+60%) Production/Emission Tg/yr 20002100 A1B SOx 150.0 SOx 56.4 (-62%) GLOBAL SOA 9.7 POA 7.7 SOA 11.8 (+22%) POA 10.5 (+38%) Production/Emission Tg/yr 20002100 A1B SOx 4.5 SOx 4.3 (-4%) SOUTH AMERICA

6. PREDICTED LAND-USE CHANGE? 2000 2100-2000 Deforestation (loss of isoprene emitters) at expense of cropland expansion. Additional effects of economics on crop choices, of climate change… Based on IMAGES 2.2 model of IPCC scenario A2 (adapted to CLM by Johannes Feddema)