Ponderosa pine has a lot of genetic variability and built-in developmental flexibility and thus, if seed sources can move in time, it can be considered fairly adaptable to new environments.…
What Americans Really Think About Climate Change
By Melanie Lenart, University of Arizona
Jon A. Krosnick, a political psychologist at Stanford University, pulled together results from various polls during his many years of social research to argue that most Americans believe in the existence and threat of climate change and have done so for over a decade.
Using findings from survey research he and his colleagues conducted since 1997, Krosnick explained during an hour-long presentation on April 19 at the University of Arizona that their research challenges …
Jet Stream Activity in Climate Models
Adapted from: Lenart, M. Basics of Regional Models. (September 14, 2008). Southwest Climate Change Network
Jet streams high in the atmosphere direct where moisture lands on the surface. Global climate models (GCMs) generally do a good job at simulating jet stream activity, especially in the mid-latitudes – roughly 40 to 70 degrees north of the equator. Indeed, this is considered one of their strengths. Even so, potential problems include inadequacies where the mid-latitudes interact with the tropics (Bader et al. …
Importance of Temperate Forests in Climate Adaptation
Written by Bill Stewart, University of California Berkeley
The varying estimates of the role of tropical deforestation in the emission of greenhouse gasses have dwarfed the unique role that temperate forests play in mitigating the negative impacts of greenhouse gas additions to the atmosphere. In 2010, forest-related measurements for CO2 reduced the negative impacts from tropical deforestation and reaffirmed the large and growing carbon sink provided by managed temperate forests (Friedlingstein 2010).
Temperate forests have historically been well mapped …
How Does the Monsoon Affect Arizona?
Regional Differences: The North American Monsoon System
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Adapted from: Michael Crimmins.
…How Does the Monsoon Work?
Regional Differences: The North American Monsoon System
Adapted from: Michael Crimmins. 2006. Arizona and the North American Monsoon System. University of Arizona College of Agriculture and Life Science. Publication No. az1417.
How Does the Monsoon Work?
The official definition for the word “monsoon” is a persistent surface windflow pattern caused by differential heating that shifts direction from one season to another (Greer 1996). The most intensively studied monsoon on Earth is the Indian, or South Asian, monsoon where …
Radiative Forcing
Excerpt from the Southwest Climate Change Network, written by Zack Guido, University of Arizona
Radiative forcing measures the influence that climate-altering factors have on the energy balance of the Earth. Examples of factors that can alter the Earth’s energy balance include atmospheric concentrations of greenhouse gases, aerosols from volcanoes and air pollution, and the amount of solar radiation delivered to the Earth by the Sun.
In a state of equilibrium, solar radiation entering the atmosphere equals the radiation that …
Monsoon Season in North America
Regional Differences: The North American Monsoon System
Adapted from: Michael Crimmins. 2006. Arizona and the North American Monsoon System. University of Arizona College of Agriculture and Life Science. Publication No. az1417.
Monsoon Season in North America
The circulation features that bring monsoonal moisture into the southwest United States are typically in place by late June or early July and persist through mid- to late September. The arrival of substantial monsoon moisture varies greatly from year to year. This …
Greenhouse Gases
Excerpt from the Southwest Climate Change Network, written by Zack Guido, University of Arizona
Greenhouse gases such as carbon dioxide, methane, and water vapor are naturally part of the Earth’s atmosphere. These gases act as powerful amplifiers of temperature, helping elevate the average temperature in the lower atmosphere to a comfortable 60° Fahrenheit. Without greenhouse gases, the average near-surface conditions would be cold enough to freeze water, at approximately 0°F.
The greenhouse gas effect functions by trapping in the …
The North American Monsoon System
Regional Differences: The North American Monsoon System
Adapted from: Michael Crimmins. 2006. Arizona and the North American Monsoon System. University of Arizona College of Agriculture and Life Science. Publication No. az1417.
The southwestern United States receives most of its annual precipitation in two distinct seasons, winter and summer. Winter precipitation is produced by large-scale surface low-pressure systems that traverse the southwest, drawing in moisture from the Pacific Ocean and producing widespread rain and snow (Figure 1a). Energy to fuel …