Biomes

In many instances it is necessary to plot more than one type of data on the same chart. High-low (stock) graphs give scientists the ability to plot three values (high/low and average) on the same chart, while combination plots provide the capability of plotting two totally different variables on the same graph by using two different y-axes. In other instances, scientists use logarithmic (log) plots either to study exponential functions or ones in which there is a large range of values.

Activity 20.7.2 – Combination graphs: Graphing two types of data on one chart

• 20.7 Google Sheer - Bimoes - Combination Graphs - Climographs
• If you prefer to use Excel click here

It is often helpful to plot two different types of data on the same graph. For example, a climograph (figure 20.24F) is a single graph that charts both the average temperature and precipitation for a given locale throughout the course of the year, using separate axes for each variable. As shown in figure 20.24F, the line graph represents temperature, while the bar chart represents precipitation. The horizontal axis represents the months of the year. The climograph not only shows average temperatures for each month, but also illustrates seasonal variations in temperature over the course of the year. Likewise, the climograph reveals monthly precipitation and seasonal variations in precipitation. Combination graphs, like the climograph, must have the same independent variable (x-axis), but can have different dependent variables (y-axes). Note that the axis on the left is precipitation, measured in millimeters of rainfall, while the axis on the right is temperature, measured in degrees Celsius.

To Add a second Y-axis to a chart - "Certain chart types allow you to add a second Y-axis in order to represent your data on two different scales at the same time. This is particularly useful for combo charts, which show two data series. Using the second Y-axis option, you can scale each series separately, making your chart clear and easy to read. To add a second Y-axis to your chart, go to the Customize tab in the Chart Editor and scroll down to the Series section. From the drop-down menu, select the name of the series you’d like to scale to the right. Then, select Right axis from the drop-down menu next to Axis. You can also add a second Y-axis directly in the chart if you are in quick edit mode, which is accessed by clicking the pencil icon in the top left corner of the chart. For charts that allow a second Y-axis, you can right click on a bar or line in the chart (based on the chart type) and select the right axis icon to add the extra axis." (from)

• Video Climographs, Combination Charts (32:42). This video will show you many important features on graphing using Google Sheets

(1) Analyzing climates with climographs. Compare the climographs for Quito’s, Peru, and Barrow, Alaska. The graphs look very different with respect to temperature and rainfall, indicating that these are very different climates. The temperature graph for Iquitos is linear and flat, indicating little or no variation in temperature during the course of the year. By contrast, the temperature graph for Barrow appears like a sine wave, with a maximum in June, July and August, and a minimum in December, January and February. From this we can conclude that Barrow is in the northern hemisphere (a city in the southern hemisphere would have maximum temperatures during December, January and February). Although the summer months are much warmer than the winter months in Barrow, they are still very cool, indicating that this city must be located very far north. Indeed, Barrow is on the northern coast of Alaska (Figure 20.24C). The climate in Barrow is cold and dry. It is so cold, however, that water rarely evaporates from the soil, leaving the soils wet and often frozen, a characteristic of arctic tundra. By contrast, the climate in Iquitos is warm and wet, indicating it will support a large amount of vegetation, and indeed it is found in the tropical rainforests of Peru. Analyze the climographs in figure 20.25 to answer the following questions.

(a) Which city has the most equable (constant) climate? Explain.

(b) Which city has what most people would consider the most comfortable climate?

(c) Chicago and New York have approximately the same climographs, except that Chicago’s winter is colder. Why might this be?

(d) Which of these cities is located in a hot desert?

(e) Which city is in the Southern Hemisphere?

(f) Which of these cities is located in tropical rainforest?

(g) Which of two of these cities have a Mediterranean climate, characterized by mild winters and warm, dry summers?

(h) Which city would experience monsoon type rains (heavy, summer rains)?

(i) Which city has the coldest, driest summers?

(j) Which of the following cities has the most annual rainfall, Chicago, New York, Dallas, or Miami?

(k) Which of the following has more summer rainfall, Denver, Los Angeles, or Seattle?

(l) Which city has a climate most similar to Chicago?

(m) Which of the following cities would be best suited for outdoor ice skating rinks: Chicago, New York, Dallas or Miami?

(n) Which has more winter rainfall, Mangalore, India, or Seattle, Washington?

(o) Which city has two “wet” seasons?