Ozone Formation and Impact on Agricultural Yield and Human Health

1. Ozone Formation and Impact on Agricultural Yield and Human Health Moti L Mittal moti@osc.edu Ohio Supercomputer Center/The Ohio State University, Columbus Ohio (USA) BAQ 2004 Workshop 6-8 December, 2004, Agra

2. Ozone is short-lived.. Tums for climate system? Long-Lived Species • CFC’s • N2O Junge relationship- • CH4 What it means to O3 • CH3CCl3 • CH3Br Moderately Long-Lived Species • CO 1s 100s 1hr 1 day 1yr 10 yrs 100 yrs • Aerosols • Trop O3 • SO2 • H2O2 • NOx • DMS • C3H6 • C5H8 Short-Lived Species • CH3O2 • HO2 • NO3 0.001 0.01 0.1 1 10 100 1000 10,000 Ozone- a special molecule Ozone is a greenhouse gas and an oxidant • Ozone is a UV shield – its stratospheric loss is harmful. • Ozone is a pollutant in the troposhere – contact is harmful. • Ozone is an oxidant – it controls the ability of the troposhere to clean itself. • Understanding Troposheric Ozone is key to climate and regional air quality. • Ozone contributes 8-15% to the total radiative forces associated with greenhouse gases. • Ozone is MADE in the atmosphere – not emitted into the atmosphere. • What is the abundance of troposheric O3 ? What determines it’s abundance?

3. PHOTOCHEMISTRY Source 400 420 Production = 4100 Sink 820 Destruction = 3680 420 Net photochemical production Q: What is the contribution of stratosphere to tropospheric O3 - Stratosphere/Troposphere exchange Varies with z, - in-situ photochemical production location, and season - Transport from other regions? Stratosphere-troposphere coupling A key issue: Ozone production and removal in the troposphere Altitude, km

4. Computational Model • Covers Indian Region from -.9ºN to 58.5º N and 42.6º E to 66.5ºE and is gridded with 91x 91 horizon mesh. • MM5 – for meteorological variables • HANK – for chemical species

5. HankThe model considers *154 Reactions *28 photolysis reactions *49 transported species (non-steady state) *54 reactive species

6. Comparison of Measured and Model Values Comparison of diurnal variation in January at Agra

7. Comparison of Measured and Model Values Comparison of diurnal variation in January at Agra Comparison of diurnal variation in January at Agra

8. Monthly Average O3 Concentration

9. Ozone Hotspots over NW India

10. Ozone Hotspots over NE India

11. Ozone Hotspots over SW India

12. Ozone Hotspots over SE India

13. Impact on Agricultural Yield (Exploratory Assessment) A recent study shows that China, Japan, and South Korea lost 1-9 % yield of wheat, rice, and corn and 23-27% yield of soybeans, of 1990 US$ 3.5, 1.2, and 0.24 billion Increased Ozone levels decrease the growth rate of trees that store CO2

14. Health Effects • Ozone as a toxic gas can damage the pulmonary tissues. • Ozone may affect the circulatory system. • Recent study in Hong Kong suggests ozone may increase risk of cardiac arrhythmias and heart failure in the elderly population. • Studies are needed on the health effects of ozone in Asian region

15. Summary • Chemistry-Climate Interactions include many factors • Tropospheric ozone is an important issue in climate (& air quality) • Emission inventory is important (1) Laboratory studies, field measurements, and “modeling” can describe and “quantify” chemical/transport(?) processes. (2) How do we incorporate this information to assess productivity loss, impacts, etc.? National Crop Loss Assessment Network is an idea Going beyond “case studies” and “proof of concept” - the next frontier.