make temperature change appear linear and constant, which frequently it is not.

ID: 116403 • Letter: M

Question

make temperature change appear linear and constant, which frequently it is not. Best-fit lines are often superimposed over the annual- and 5-year running averages, creating a useful composite "snapshot" with several levels of data generalization on the same chart (such as has been done in Figure 6). Similar techniques can be used when looking at long-term precipitation patterns, such as is shown for Bozeman and Tucson in Figure 7.The precipitation variability of a location describes the expected departure from average ("normal") precipitation in any given year. Precipitation vari- ability is generally greater in dry climates than in humid ones. 75 Tucson 70 65 60 50 Bozeman 45 Figure 6: Average annual temperature in Tucson, Arizona; Bozeman, Montana; and Nome, Alaska, from 1905 to 2015. Five-year moving average shown with thick trend line; "best fit" shown with thin straight line. (Data sources: National Climate Data Center and Alaska Climate Research Center, University of Alaska, Fairbanks) 40 35 Nome 25 Tucson Bozemarn 1" average shown with thick trend line; "best-fit" line with thin straight line. (Data source: National Climate Data Center) Figure 7: Annual precipitation in Tucson, Arizona, and Bozeman, Montana, from 1905 to 2015. Five-year moving

Explanation / Answer

7)a)

1. It has stayed the same

2. It has decreased

3. It has increased

b) Volcanic eruptions are the most important factor. Other factors appear to be more important.

a) The positive phase of the PDO.The negative phase of the PDO.

b)The negative phase of the PDO.The positive phase of the PDO.

a) 2.6 °Fb) 0.6 °F

c) 1.6 °F

d) 3.6 °F

10 Tucson decreases, Bozeman increases

11a)Tucson and Tucson

Wet climates have more precipitation variability. Dry climates have more precipitation variability

Tucson-no

Bozeman-yes

a) Bozeman and Bozeman

b) Being farther from the ocean makes it more likely that Bozeman would get more humid air from the Pacific than in the Southwestern US.The southwestern U.S. tends to have a greater increase in precipitation during an El Niño event than the north-central U.S. (same as the Imperial Valley!)