GEOG 310 Exercise Five (F2000)
NORTH AND EBMODEL 1-D ENERGY BUDGET MODELS
10 points
Name:_______________________
SS#:________________________
Your goal in this exercise will be to explore the differences in global climate associated
with various carbon d ioxide co ncentrations. You will examine levels during t he Pleisto cene
(.018%), in 1800 (.028%), today (.035%), and projected for 2050 (.053%).
Part I. NORTH MODEL
The North mod el is r elat ively se lf-ex plana tory. T ake adva ntage o f "He lp" w hene ver it is
offered.
1. Select CD (Carbon dioxide concentration) as your experimental variable. Use each of
the following relative levels for a different experiment (be sure to reset to pr esent climate (PC)
after each): Pleistocene (.5), 1800 (.8), today (1)--present climate, 2050 (1.5).
2. For each o f the fou r case s fill in the table (o n next pa ge) and repo rt the values o f the
response variables: TM (mean temperature), temperatures at 0°, 25°, 50°, and 75° latitude (use
LV opt ion) , S L (s now co ver lat itu de) , AP (pla net ary a lbedo ), and t he lat itudinal v aria tio n var iable
TG (equator to pole thermal gradient).
Part II. EBMODEL
The EBMODEL is a much more sophisticated EBM, although still 1-D, and therefore
very simplistic compared t o the stat e of t he art GCMs. Please read the accompanying
documentation on the program BEFORE attempting to run it. The program can produce
SEASONAL runs which include the variations of the seasonal cycle, but we will be using the
ANNUAL MODE in this exercise, which averages the months at each latitude
(there is also a GLOBAL mode, which work similarly to the ZERO model). Be sure to look at
the very nice graphs and tables.
1. Do four separate ANNUAL MODE runs corresponding to the times used in the NORTH
model. Set albedo feed back to -0.111 for ALL of the scenarios below.
a. today: run with current values (default, except for albedo feedback)
b. Pleistocene: set time change to -12000 and CO2 to 175 ppm
c. 1800: set time to 1800 and CO2 to 280 ppm
d. 2050: set time to 2050 and CO2 to 525 ppm
2. For each of the four runs record the Global Average Temperature, and the Northward Heat
Transport value at 50°N.
Part III. Interpreting the models
3. Using the information from the model runs and your knowledge of causes of global circulation
(and other da ta pro vided by the mod el if re levan t, suc h as SEAS ONAL RUN S), speculate in
three short paragraphs (on the back of this page) how the general circulation and its features
(ITCZ, Sub.-Trop. H igh, Jet St ream) we re d iffere nt t han tod ay du ring the Pleisto cene and in
1800, and also how they might be in 2050.
