Part 5—View Temperature Trends in Google Earth
Step 1 Investigate Temperature Trends in the Arctic
In this part of the chapter you will view two temperature change (trend) maps generated using NASA Goddard Institute for Space Studies (GISS) data, and compare them to the borehole data graphs that you created in Part 4. The GISS surface temperature analysis Web site and data archive has data from three publicly available sources: weather data from more than one thousand ground-based meteorological stations distributed around the world; satellite observations of sea surface temperature; and Antarctic research station measurements. These data are loaded into a computer program that constructs gridded fields, or maps, of surface temperature, from which maps of temperature changes over time (trend maps) can be constructed. To make your own maps see http://data.giss.nasa.gov/gistemp/maps/. In this example we chose "Trend" for the map type, "Winter" and "Summer" for mean periods, and 1950-2009 for the time interval. We then converted the resulting 2-D pictures so they could be viewed as layers in Google Earth.
- If necessary, launch Google Earth and re-open the Permafrost EET.kmz file. Zoom to the region around Chersky and the Borehole data locations. Adjust the layers as needed.
- Turn off the Permafrost Map layer.
- Turn on the Surface Temperature Trends Maps layer. Activate the Summer (Jun - Aug) temperature and GISS Summer Legend layers, so that you can see what the summer temperature trend has been between the years between 1950 and 2009. What is the most common temperature increase in the Northern Hemisphere?
- Next, turn off the Summer (Jun - Aug) temperature layer and its legend, and turn on the Winter (Dec - Feb) temperature layer and the GISS Winter Legend.
How does the data in this layer compare with the Summer layer?
Step 2 Compare Temperature Trends and Reflect on your Observations
- With your Excel graphs open, examine the temperature trends shown in the Yakutsk borehole data alongside the GISS Surface Temperature trends on the Google Earth map. Consider the following questions:
- Are there similarities between the two datasets (surface and borehole data)?
- What questions do you have about the data?
- Are there further borehole locations that you would like to examine?
- Now that you are knowledgeable about permafrost and have observed for yourself how it has changed – at least in terms of temperature – over 50 years, what would you say to Pieter and his classmates? Do you suppose the village elders in Chersky would agree with your observations? Given more recent data (2000-the present) about surface air temperature, what would you predict is happening to permafrost temperatures in the same time period?
In a word-processing document or on a piece of paper, write out your thoughts and conclusions about the trends that you have observed.What advice might you offer to the residents of Chersky based on your observations?