Geog. 321 -- Climatology
Exercise 8 -- Climate Trends

This exercise focuses on longer-term trends in climate (over the past 50 or 100 years), both for the globe and for the US in particular.  The exercise makes use of analyses prepared by the National Climatic Data Center (NOAA) and the Climate Prediction Center (NOAA). 

Note:  This exercise makes use of "live" web pages, which may not be available when you work on the exercise.  If, after 15 minutes or so of trying, you are unable to reach the NCDC or CPC servers, you can, without loss of credit, enter "page not available" and the date and time as an answer.

Warning:  The links below should open the web pages in a new browser window, and when you're done with each question, you might want to close the window that you have been examining.  However, make sure you don't close this window because any text already entered will be lost.

Please enter your Name before beginning (Last Name, First Name):

And your email address:

Global Climate Trends -- Annual Reviews

The most recent annual summary of global climate change produced by the National Climatic Data Center is the one for 2006:  

Climate of 2006 -- Annual Review
http://lwf.ncdc.noaa.gov/oa/climate/research/2006/perspectives.html

Here's a direct link to the Global Analyses part of the Annual Review:

http://lwf.ncdc.noaa.gov/oa/climate/research/2006/ann/global.html

Examine the the global temperature time series plot at the top of the web page (click on it to enlarge), the global precipitation plot (near the bottom of the page), along with the related plots elsewhere on the page (i.e. look at the whole page).

Question 8-1:  Describe the global temperature trend over the past 120 years, and the preciptation anomaly for 2006.  What is the overall trend in temperature like?  Is it steady, or are there ups and downs?  Where during 2006 was it warmer than the long-term (1961-1990) base-period average, and where was it colder? Where was it wetter than normal, and where was it drier.

2007 Monthly Climate Anomalies

Next, take a look at the most recent monthly summary (September or October 2007):

Climate of 2007 (US and Global Perspectives)
http://lwf.ncdc.noaa.gov/oa/climate/research/2007/perspectives.html

  • Follow the link to "2007 Monthly Reports" and click on the most current month (September or October).  (Note that the October 2006 global summary will not be available until about 15 November.  If October is unavailable when you do this exercise, you can use the September 2006 summary.) 
  • That link will take to a page called "Climate of 2007-- September (or October) in Historical Perspective".  Scroll down on this page to find the section called "Global Analysis" and
  • click on the link "Global Temperatures."

Here's a direct link to the Global Analysis

http://lwf.ncdc.noaa.gov/oa/climate/research/2007/oct/global.html

Question 8-2:  Have the trends you observed earlier been maintained during 2007 through September or October?  Does it look like 2007 will be warmest year ever?  One of the ten warmest?  A generally cold year?  Is there any sign of a reversal of the century-long warming trend?

US Temperature and Precipitation Trends

Temperature and precipitation trends for the US over the past few decades are illustrated by some analyses and graphics from the Climate Prediction Center (NOAA).  In particular, these illustrate the sign (increasing or decreasing) and rate (faster or slower) of the trends in climate over the past 35 years.  These are available at:

US Temperature and Precipitation Trends
http://www.cpc.ncep.noaa.gov/trndtext.shtm

  • Click on the link to the "Graphics" page, and
  • examine the maps for January-February-March and June-July-August

Question 8-3:  Describe the spatial pattern of temperature and precipitation trends over the US.  Are the temperature trends consistent with the global- or hemispheric-average trends?  What does the spatial pattern of the precipitation trend look like?  If a local trend is opposite in sign from the global trend (e.g. negative (decreasing) when the global trend is positive (increasing)) does that mean the global trend is nonsense?

Seasonal Variations of US Temperature and Precipitation Trends

Finally, look at the seasonal variations of the national (averaged over the 48-states) trends:

National Temperature & Precipitation Trends by 3-Month Periods & Full Year
http://www.cpc.ncep.noaa.gov/trendusa.gif

Each bar on these plots shows the trend in the national average for overlapping three-month "seasons".  This plot can be compared with the mapped summaries to get an idea of the spatial pattern of the trends in individual seasons.

Question 8-4:  Describe the seasonal variations of the temperature trend.  What time of year is the change in climate the fastest, and what is its direction?  What might account for a greater trend in one time of year as opposed to another?  

 

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