1. Global Ozone Project Curriculum Rev 13 Lesson 6: Oxides of Nitrogen (NO x )

2. Learning Objectives At the end of this lesson students will be able to: Identify the two forms of nitrogen that make up NO x and lead to the formation of ground level ozone. Understand the sources of NO x globally that contribute to the formation of ground level ozone. Identify examples of natural and anthropogenic sources of NO x in the atmosphere. Describe the role of NO x as a “Chemical Switch”. Lesson 6: Oxides of Nitrogen (NO x )

3. Exploration of Precursors in Depth Oxides of Nitrogen (NO x ): NO, NO 2 Examples of nitrogen sources Breakdown of anthropogenic sources (cars, power plants, etc.) Breakdown of natural sources (swamps, trees, etc.) Carbon Source CO, CH 4 & VOCs Oxides of Nitrogen (NOx) NO, NO 2 ozone precursors Lesson 6: Oxides of Nitrogen (NO x )

4. Ozone needs oxides of nitrogen in order to form. Here are the two NO x compounds: NO (Nitric Oxide) NO2 (Nitrogen Dioxide) Examples of NO x Lesson 6: Oxides of Nitrogen (NO x )

5. Global Anthropogenic Sources of NO x Lesson 6: Oxides of Nitrogen (NO x )

6. Breakdown of Global Anthropogenic Sources of NO x Does anything about this breakdown jump out at you? Lesson 6: Oxides of Nitrogen (NO x )

7. Global Anthropogenic NO x Emissions Density Legend NO x Total 2000 FT Units = Megagrams of NO x (1 Megagram = 10 6 grams = 1,000,000 grams) 0 – 3 Mg NO x per cell 3 – 30 30 – 300 300 – 3,000 3,000 – 10,000 10,000 – 30,000 30,000 – 900,000 Mg NO x per cell Lesson 6: Oxides of Nitrogen (NO x )

8. Regional Breakdown of Total Global Anthropogenic NO x Emissions Lesson 6: Oxides of Nitrogen (NO x )

9. Anthropogenic Sources of NO x in the United States Lesson 6: Oxides of Nitrogen (NO x )

10. NO x Emission Inventory for the United States Emission Inventories are created to tally the amount of NOx emitted by each region of the county, in this case by county. If you live in the US, what is your county's NOx Emission Density? Lesson 6: Oxides of Nitrogen (NO x )

11. Breakdown of Anthropogenic Sources of NO x in the United States What are the top three sources of NO x in the US? Lesson 6: Oxides of Nitrogen (NO x )

12. Natural Sources of NO x Lesson 6: Oxides of Nitrogen (NO x )

13. Anthropogenic Emissions Contribute the Vast Majority of NO x Globally Lesson 6: Oxides of Nitrogen (NO x )

14. Let’s Look at One of the Most Significant Natural Source of NO x Globally: Lightning This image shows how lighting strikes are distributed around the world. The units are in lightning flashes per square kilometer per year. This gives us an idea of where on the earth NO x is created from lightning. Lesson 6: Oxides of Nitrogen (NO x )

15. NO x as a “Chemical Switch” Lesson 6: Oxides of Nitrogen (NO x )

16. Before Anthropogenic Emissions… … there was a relatively low concentration of NO x in the air. With a low concentration of NO x in the Atmosphere, the series of reactions actually leads to the destruction of ozone! Lesson 6: Oxides of Nitrogen (NO x )

17. Anthropogenic Emissions have Tipped the Atmospheric Balance… … and Now these Compounds Interact in Ways they Don’t Normally. With a high concentration of NO x in the Atmosphere, the series of reactions leads to the formation of ozone High Concentration of NO x : Lesson 6: Oxides of Nitrogen (NO x )

18. The Concentration of NO x in the Atmosphere Can be Thought of as a “Chemical Switch” Low NO x O3O3 O2O2 Ozone Production = OFF (ozone is actually destroyed) O3O3 O2O2 Ozone Production = ON High NO x Lesson 6: Oxides of Nitrogen (NO x )