[ADD YOUR COURSES DETAILS HERE] Quantifying Precipitation and Temperature in the Northeast United States [ADD YOUR COURSES DETAILS HERE]

Agenda Quantifying temperature and precipitation activity (45 min) Visualizing this with EdGCM (15 min)

Questions for this Activity How has the climate of the Northeastern United States changed over the past centuries and decades? What are the current precipitation and temperature trends in Northeast? How are temperature and precipitation patterns expected to change in the future?

Climate Change, Temperature, and Precipitation A changing climate alters patterns of temperature and precipitation as a result of altered feedbacks like: Sea ice extent Fossil fuel combustion Solar variability Changes in these patterns can manipulate the global circulation of heat, water, and other atmospheric components

We will be using a climate reanalyzer to look at some correlated trends. In particular, trends in precipitation and temperature between 1979 and 2015

How Has Temperature Changed in New England? Feel free to work with a partner. I will come around with a dataset for you to use. Instructions 1. Using Sheet 1 “Temperature,” we will make a line plot with three lines: Average for December – January vs. Year Summer (DJF) vs. Year Winter (JJA) vs. Year 2. This can be done by selecting “Insert” → “Line.” If the plot doesn’t look right, make sure you Right/Command + Click → “Select Data” and specify what values you want for your “X Axis” 3. To more easily read your chart, you may also wish to move the year values below the chart. To do this, right click on them, choose “Format Axis,” and then choose “Low” in the appropriate section (which may vary depending on which version of Excel you have). 3. You may also wish to add axis labels, a title, and unit labels to your plots. Finally, is it hard to see one of the lines? Try plotting each line separately, adding markers, or adding data labels to better see the differences. Data is based off of a 1901-2000 Mean

How Has Temperature Changed in New England? As a group, let’s now answer some questions about what temperature looks like in the Northeast United States over the past century: 1. Roughly, how many degrees Celsius does temperature increase each year? Each decade? 2. How is the DJF line different than the JJA line? 3. Why do you think this difference exists? Data is based off of a 1901-2000 Mean

How Has Precipitation Changed in New England? By using local data from Portland International Jetport, we will examine precipitation trends since 1940.

How Has Precipitation Changed in New England? Feel free to work with a partner. I will come around with a dataset for you to use. Instructions 1. Using Sheet 2 “Precipitation,” create a line graph with the two sets of annual data. One should be precipitation data and the other should be for snow. 2. This can be done by selecting “Insert” → “Line.” If the plot doesn’t look right, make sure you Right/Command + Click → “Select Data” 3. You may also wish to add axis labels, a title, and unit labels to your plots. Note: PRCP data represents annual rainfall in this case

How Has Precipitation Changed in New England? As a group, let’s now answer some questions about what precipitation look like in the Northeast United States: 1. By how many millimeters is the total amount of snow changing each year? By how much is precipitation changing? 2. How much has precipitation increased overall in the past 50 years? 3. What local impacts might these trends have?

Final Activity Question We’ve just seen changes in total precipitation, not the anomalous data as we can now see in the chart above. After examining both plots, do you think we are just seeing more precipitation or are we seeing more intense precipitation events? When it comes to precipitation and temperature, why do you think it might be important to look at anomalies rather than total amounts?

Visualizing this Change with EdGCM

Background Line graphs are great for telling us the average amounts through the years or the anomalous amounts. But they don’t tell us much about what these changes look like spatially. For the remaining 15 minutes, let’s use EdGCM to do this while also looking ahead into the future. Use whatever experimental model run you desire (I’ll work with Global_Warming_01)

Instructions 1. Following the same steps we used previously with EdGCM, extract annual data on the variables for “Surface Air Temperature” and “Precipitation.” 2. When you extract, specify that you want the 5-year average for 2046-2050 and 2096-2100. 3. Now make four maps for each variable and time period. If you want, you may also wish to make your own anomaly map to better see changes. (Remember, this requires you extracting the same variables and time periods for a control run.)

Final Discussion What new information did you gain by completing these last four graphs? How does EdGCM’s grid resolution impact your ability to predict how temperature and precipitation will change in the New England region? At the Isles of Shoals? At Appledore Island, Maine? What things might we do for our own research to get more accurate data on future changes to these variables?