The urban heat island effect

2. Theurban heat islandeffect

3. The Urban Heat Island NASA Earth Observatory

4. The Urban Heat Island NASA Earth Observatory

5. The Surface Energy Balance Latent Heat Flux (Evaporation) Solar Radiation Sensible Heat Flux Thermal Radiation Ground Heat Flux

6. The Surface Energy Balance Latent Heat Flux (Evaporation) Solar Radiation Sensible Heat Flux Thermal Radiation Ground Heat Flux

7. The Urban Heat Island: causes • Surfaces are dark, and multiple surfaces can absorb reflected sunlight • Pollution plumes absorb and reemit thermal radiation • Buildings trap outgoing thermal radiation • Cars and buildings generate heat • Industrial materials tend to absorb and retain heat • Few trees, so evapotranspiration is low and sensible heat flux is high • Buildings obstruct natural airflow and ventilation Kleerekoper et al. (2012)

8. The Urban Heat Island: cures? • White roofs [albedo]

9. The Urban Heat Island: cures? • White roofs [albedo]

10. The Urban Heat Island: cures? • White roofs • Cool pavement [albedo & ground heat flux]

11. The Urban Heat Island: cures? • White roofs • Cool pavement • Green roofs [lE]

12. The Urban Heat Island: cures? • White roofs • Cool pavement • Green roofs • Street trees [lE]

13. The Urban Heat Island: cures? • White roofs • Cool pavement • Green roofs • Street trees • Green spaces [lE, ventilation]

14. The baltimoreheat island

15. Weather Stations • http://www.ncdc.noaa.gov/cdo-web/ • NOAA has 2 long-running stations; 5 active stations • Some other data are available, but they can be hard to find

16. Weather Stations Temp (F) Erik Jorgensen

17. Weather Stations Temp (F) Erik Jorgensen

18. Weather Stations Temp (F) Erik Jorgensen

19. Weather Stations Temp (F) Erik Jorgensen

20. 38 C 25 C

23. Does any of this matter? • Extreme heat is the most deadly form of climate disaster in the United States • Studies of Baltimore have shown that high temperatures have significant health impacts • As global climate warms, the frequency and severity of extreme heat events will increase • ~80% of Americans and >50% of people worldwide live in cities, and this percentage is growing • Projected 21st C global warming: 2-12°F • Observed maximum urban heat island effect: 4-20°F

24. The B’more cool project (still working on that name . . . suggestions would be welcome!)

25. Research Questions • Can we characterize the Baltimore UHI at microscale? • Are there measureable and meaningful differences in heat between neighborhoods? • What is the reason for these differences? • Can we quantify the UHI benefits of existing and planned mitigation measures? • What are the health and economic burdens of the UHI in communities across the city? • What are the most effective heat mitigation measures, and are they worth it?

26. Describe & Explain 40C 25C

27. Generate solutions Katie O’Meara (MICA)

28. The Sensor Network Graphic: Sophie Stoerkel Design, Sophie Stoerkel, Clara Hickman, and Katie O’Meara (MICA)

29. Preliminary Results Jasmin Gonzalez

30. Preliminary Results Jasmin Gonzalez

31. Preliminary Results

32. Preliminary Results Jasmin Gonzalez

33. Preliminary Results: installation Jasmin Gonzalez

34. Preliminary Results: installation Jasmin Gonzalez

35. The Plan • Today we will assemble the radiation shields • This afternoon you will deploy the sensor outside your home (or wherever you want to deploy it) • On Monday we will analyze the data

36. Considerations for Course Planning • The iButtons cost ~$40 each. • JHU can offer to provide a small number of them for long deployments or a larger number for short deployments. • The radiation shields are made of a special reflective and water resistant material. The cost isn’t prohibitive, but we’d need to coordinate if you want them for your class. • To download data you’ll need a PC and a One-wire USB cable (they cost about $30; JHU can provide some).