Unit 3: Urban Water - Atmospheric Environment Interactions

Welcome to the course unit that explores the interactions between the urban environment and the atmosphere. Atmospheric processes, particularly components of the water cycle, are important sources and feedbacks in the urban system. After the completion of this unit, you will have learned about interactions such as 1) urban modification of surface temperature and energy exchanges, 2) water cycle components, 3) cloud-rainfall evolution within urban environments, and 4) applications to real societal challenges like urban flooding. The unit integrates basic meteorological/climatological analyses, geospatial thinking, and integration of scientific concepts within a real-world context.

What will you need for the unit?

• A computer with access to the internet will be required for this unit.

What should you do first?

1. Read the following overview reading materials on broader climate processes, urbanization-climate, and the water cycle: Global Urban Land Use Trends and Climate Impacts and Climate Impacts (Seto and Shepherd, 2009).
2. View a NASA-developed video synopsis of the complexities of weather, water, and climate: Earth's Water Cycle
3. Learn about Urban Climate Archipelagos discussed in the earthzine.org article Urban Climate Archipelagos: A New Framework for Urban Impacts on Climate (Shepherd et al., 2013). UCA concepts will be addressed in the in-class lesson as well.
4. Review PowerPoint lessons (available as a pdf file) on water cycle, urban climate and climate changes. These lectures will develop a fundamental background essential for the Geophysical Data project and the Conceptualization/Consulting project to be conducted in-class.
• Water and Climate (Acrobat (PDF) 2.1MB Jul8 16)
• Urban Climate (Acrobat (PDF) 4.3MB Jul8 16)

Take this Pre-Quiz

The Pre-Quiz will allow the instructor to determine what you know about the material before your exposure to the unit. It will help the instructors assess what you learn and find ways to improve the material for future students.

1. How does an Urban Climate Archipelago differ from an Urban Heat Island?
2. List three reasons why a city may have an urban heat island.
3. Which of the following water cycle processes is not directly modified by urbanization: evaporation, precipitation, runoff, groundwater storage?
4. Assuming that the following two statements are true, what would you advise urban planners to do about future storm water management systems in their city? Defend your answer in three sentences or fewer.
1. The heaviest 1% of rainfall events is now more intense due to changing climate (National Climate Assessment report 2014).
2. Urban impervious surfaces are increasing.
5. Are the tropical regions near the equator typically more cloudy than the mid-latitude or Arctic regions?

Activities

It is now time for you to use real geophysical data analysis. In this exercise, you will be using the Climate Wizard tool to assess precipitation and temperature variability around a city using actual PRISM gridded climatological datasets, GIS layers, and models.

Follow these instructions:

1. Visit Climate Wizard: http://www.climatewizard.org/
2. Select the state of Georgia and zoom in to the city of Atlanta.
3. Select time period "Past 50 years"

The assignment is to examine maps of "average" and "changes" in average precipitation and temperature around Atlanta, Georgia. You should plot maps of change for both variables for the following time periods:

a. Annual

b. Summer

c. Winter

Discuss the overall changes of temperature and precipitation (and trends) as a function of season around the city and consider the basic interactions among various systems (hydro-, anthro-,bio-,atmo-) to explain interesting patterns/distributions and what physical reasons might explain them (urban, topography, other factors).

Pulling it all together

In this activity, small student groups are tasked with being a consulting company that is providing a strategic plan for how to (1) map the city's urban heat island and (2) determine what months are likely to experience urban flooding. Your instructor will assign groups.

You will also be asked to revisit the concept of "Urban Climate Archipelagos (UCAs)" from the pre-class assignments. Then, read the article By 2060, the American South Could Be Three Times as Urbanized (by Laura Bliss, 2014; available on the City Lab website) and review figures (b) and (c). Reflect on how many possible UCAs may emerge in the coming decades within the Southeastern United States.

You should lay out your presentation in a persuasive and compelling slide that discusses what the weather or climate implications of the UCAs identified could be.