Hong Kong and Shenzen
Combined
Arizona and Riyadh
Bonus!
100
Are global energy demands increasing or decreasing?
Increasing
100
What physical differences exist between Hong Kong and Arizona?
Hong Kong - temperate climate, located near a harbor very dense urban population
Arizona - arid climate, located near mountains and irrigated land, more sprawling urban habitat
100
Why use pre/post urban development data for this analysis? Is there another way to collect this information?
Building a model, but this would still need data based on pre and post urban development
100
What is a SDIR?
Short Duration Intense Rain Event
200
ACWH could be an example of what find of feedback loop? (+ or -)
Positive
200
What sort of criteria did researchers look for in their experimental cities?
Current population, past population, rate of growth, rate of urbanization, location in arid or non-arid climates
200
How is Phoenix different/similar from Riyadh?
Both in arid climates, near mountains
Both had seen changes to temperature and rainfall patterns in the last 20 years (in 2006)
200
Define 'ACWH'
Air conditioner waste heat, or heat emitted continuously into the atmosphere through the use of home cooling systems.
300
How does AC use interact with the UHI effect?
Waste heat emitted from AC units increase convection air currents and bring more humidity from the ground into the atmosphere
300
What are some possible solutions to lower the effects of UHI and resulting SDIR events?
Utilize infrastructure that helps mitigate UHI (green roofs)
Prioritize more energy and heat efficient cooling systems
Promote policies that incentivize local enterprises and research institutions to explore technologies for converting waste heat into usable energy
300
Does Phoenix have a strong or weak UHI? How would this affect rainfall?
Weak UHI - 'large amounts of energy are converted into latent heat rather than sensible heat due to the prevalence of irrigated lands'
p.618 - When UHIs are weak, surface sensible heat fluxes , convergence, and buoyancy variations that influence rainfall development are most effective at a distance from the central heat source (Thielen et al 2000)
300
Did humans modify the humidity in the air in/around Phoenix? How?
yes, addition of irrigation
400
How might the presence of high rise buildings affect SDIR events?
High rise buildings impede wind flow, trapping more heat between buildings.
Taller buildings have more surface area exposed to solar radiation, which also traps more heat.
400
How might urban heat dynamics react differently within an arid climate vs. a more temperate climate?
More moisture in the air = more potential for intense rain events
Arid climates rainfall will be more seasonal (with monsoons) vs. year round
400
What is different about how these cities receive rain?
Phoenix receives rain through the monsoon season in the summer
Riyadh is very dry, but receives rainfall in the highlands and mountainous areas of the country (also monsoon related)
400
How might the input of humidity from human activities affect precipitation patterns in a dry climate vs a naturally humid climate?
Likely increase rain events through the addition of humidity to the atmosphere, which would be more noticeable in a climate where humidity is not regularly in the air
500
Why might SDIR events occur late night/early morning in Hong Kong, but just in the early afternoon in Shenzen?
-ACWH emissions peak in the afternoon
-ACWH has stronger warming effect during the daytime, vs. the nighttime
(p.7),(Refer to Figure 5)
It is likely that the proximity of Hong Kong to the ocean led to more humidity in the air, so more humidity was brought into the atmosphere, leading to more rain events.
500
If I am trying to decrease the number of SDIR events in Hong Kong by installing newer, more energy efficient cooling solutions, would I be able to use the same mitigation techniques in Arizona? In which city would it be more effective?
Cooling solutions in Hong Kong could help in Phoenix, but might not be as effective due to the different structure and climate of the city.
SURPRISE QUESTION!
Why might this be?
500
What is the possible cause of the anomaly seed south of Phoenix in Figure 7? (pg.618)
Convection and outflow from the mountains interacts with urban induced convection from Phoenix, resulting in convergence and flux forcing on the edge of the city
500
How can we plan additions to cities to mitigate the addition of ambient heat?
By using energy efficient cooling systems (any examples?)
adding vegetation - vertical gardens, tree planting, green roofs
changing policies to encourage the adoption of these practices