Page 236 - Geosystems An Introduction to Physical Geography 4th Canadian Edition

THEhumanDENOMINATOR 7
Atmospheric Moisture
ATMOSPHERIC MOISTURE HUMANS
• Water in the atmosphere provides energy that drives global weather systems and affects Earth’s energy balance.
• Humidity affects human comfort levels.
HUMANS ATMOSPHERIC MOISTURE
• Water vapour is a greenhouse gas that will increase with rising temperatures from climate change.
7b
Morning Glory clouds are rare, tubular clouds that form in only several
locations on Earth. Northern Australia’s Gulf of Carpentaria is the only place where they are observed on a regular basis. Gliders flock to this area to ride the associated winds. Learn more at www.morninggloryaustralia.com/.
[Mick Pertroff/NASA.]
7a
To reduce the frequency of deadly fog-related traffic accidents in parts of California’s Central Valley, electronic freeway signs warn drivers when potentially hazardous road conditions exist. [Jeremy Walker/Getty Images.]
7c
30
20
10
0
40
350 300 250 200 150
Temperature (maximum)
Tempera Precipita
ture tion
(minimum)
7d
A net captures moisture from advection fog that forms over the cold Humboldt Current in the Pacific Ocean and creeps toward the Andes Mountains of Chile and Peru.Netssuchasthiscancollectupto5L·m–2 of water, which translates to 200 litres each day per net, a significant amount in this dry region. [Mariana Bazo/ Reuters.]
The tropical climate of Malaysia is hot and
J F M A M J J A S O N D
Months
humid all year. In Singapore, at the tip of the 100 Malay peninsula, daily relative humidity
averages 84% and often exceeds 90% at 50 night. Rain falls on most days, and dramatic
afternoon thunderstorms can occur
0 throughout the year. [ak_phuong/Flickr Open/
Getty Images. Climate data from WeatherWise Singapore.]
ISSUES FOR THE 21ST CENTURY
• Fog will continue to be used to supplement drinking water supplies in some regions of the world.
• Rising temperatures affect evaporation and condensation rates, in turn affecting cloud formation. Ongoing studies indicate that cloud cover will be less in a warming world, creating a positive feedback that accelerates warming.
geosystemsconnection
We explored the remarkable physical properties of water and began our discussion of the role of water in the atmosphere. We looked at humidity concepts, which underlie the dynamics of atmo- spheric stability, and at the formation of clouds and fog. With this foundation we move to Chapter 8 and the identification of air masses and the conditions that force these to lift, cool, condense, and produce weather phenomena. Also, we look at violent weather events, such as thunderstorms, strong winds, tornadoes, and tropical cyclones.
Temperature °C
Precipitation (mm)
200