1. http://www.ncdc.noaa.gov/oa/climate/research/2005/ann/ann05.html

3. Local Weather and Climate: The North American Monsoon Tucson gets half of its rainfall during the summer Sonora, Mexico gets most of its rainfall during the summer During summer, high pressure sets up to the east/northeast of Arizona which brings moisture in from the south The monsoon is still going: Thunderstorms yesterday For a monsoon overview and daily forecast, see: http://www.wrh.noaa.gov/twc/monsoon/monsoon.php http://www.atmo.arizona.edu/products/models/forecasts/forecast.html

4. July minus June Rainfall Douglas et al (1993)

5. Local: Recent Monsoon Rainfall Record water flow through the Sabino and Rillito Creeks on July 31 Rillito flow higher than Colorado river! See http://fpnew.ccit.arizona.edu/kkh/rillito.flood.jul.06.htmhttp://fpnew.ccit.arizona.edu/kkh/rillito.flood.jul.06.htm

6. Course Building Blocks Intro  1 st week or so Energy  ~2 weeks Moisture  ~2 weeks Dynamics  ~3 weeks Above are interdependent Specific Topics  ~6 weeks

7. Atmospheric Composition Permanent Gases N 2 and O 2 are most abundant gases Percentages hold constant up to 80 km Ar, Ne, He, and Xe are chemically inert N 2 and O 2 are chemically active, removed & returned Ahrens, Table 1.1, 4 th Ed.

8. N 2 Boiling point: 77 °K or -196°C or –320 °F O 2 Boiling point: 90 °K or -183 °C or -297 °F N 2 and O 2 Balance between input (production) and output (destruction): Input:plant/animal decaying Output: soil bacteria; oceanic plankton-->nutrients Input:plant photosynthesis Output: organic matter decay chemical combination (oxidation) breathing

9. Atmospheric Composition Important Trace Gases Ahrens, Table 1.1, 3 rd ed. Which of these is now wrong even in the 4th edition of Ahrens?

10. Sources vegetative decay volcanic eruptions animal exhalation combustion of fossil fuels (CH 4 + 2 O 2 > 2 H 2 O + CO 2 ) Sinks photosynthesis (oxygen production) dissolves in water phytoplankton absorption (limestone formation) Carbon Dioxide CO 2

11. CO 2 Trend “Keeling Curve” Some gases vary by season and over many years. The CO2 trend is the cause for concern about global warming. CO 2 increases in northern spring, decreases in northern fall See http://earthguide.ucsd.edu/globalchange/keeling_curve/01.html

12. H 2 O Vapor Variability Precipitable Water (mm) Some gases can vary spatially and daily

13. Aerosols 1 cm 3 of air can contain as many as 200,000 non-gaseous particles. –dust –dirt (soil) –ocean spray –volcanic ash –water –pollen –pollutants

14. Aerosols - Volcanic Ash Fig. 1-4, p.6

15. Aerosols - Dust Particles Dust Storm on Interstate 10, between Phoenix and Tucson, AZ.

16. Aerosols Provide condensation nuclei for water vapor. Provide a surface area or catalyst needed for much atmospheric chemistry. Aerosols can deplete stratospheric ozone. They can also cool the planet by reflecting sunlight back to space.

17. Reading Assignment Ahrens Pages 1-22; 425-426-427 (Appendix A: Units etc.), 431-432 (Appendix C: Weather chart symbols) Problems 1.2, 1.3, 1.10, 1.14, 1.17, 1.18, 1.20 (1.17  Chapter 1, Question 17) Don’t Forget the 4”x6” Index Cards