1
ASSIGNMENT #2: Teleconnection Patterns
Go to the class web site and download the following files to your computer:
exercise2_P1.R
exercise2_P2.R
exercise2_P3.R
exercise2_P4.R
pna_all_DJF_1950-2013.dat
pna_warm_DJF_1950-2013.dat
pna_cold_DJF_1950-2013.dat
nao_all_DJF_1950-2013.dat
nao_warm_DJF_1950-2013.dat
nao_cold_DJF_1950-2013.dat
Next, start up “R” and at the prompt (>>) enter your name in the following way:
name<-“Jane Doe”
Important: Be sure to do this before you run each new program.
This step is very important since it will identify you on the results of your work. If your
name does not appear appropriately on the graphical output that you hand-in with your
completed assignments, you will receive no credit for this assignment. In addition, if you
omit this step, the R-programs for this exercise will not work correctly and you will get an
error message.
Print out and hand in all the figures generated by the programs for this assignment.
Points for each problem are given as a guide. Though we will not change these values
typically, we reserve the right to do so as we feel appropriate and necessary in grading.
Geostrophic Balance and Atmospheric Winds
As we discussed in class, the pressure gradient force and Coriolis force are generally equal and
opposite in the atmosphere (and ocean) which is referred to as geostrophic balance. The resulting
winds (and currents) are referred to as geostrophic winds (or geostrophic currents).
2
Question 1:
Figure 1 shows idealized maps of high and low pressure in the atmosphere in the northern
hemisphere (Figs. 1a and 1b) and in the southern hemisphere (Figs. 1c and 1d). Each circular line
in Fig. 1 represents a contour of constant of pressure (i.e. an isobar). In each figure, use arrows to
indicate the direction of the geostrophic winds. Use heavy or thicker arrows in places where you
expect the winds to be stronger than elsewhere. (12 points)
Figure 1: Contour maps of atmospheric pressure in the northern hemisphere for (a) a high pressure
system, and (b) a low pressure system. Each contour is a lines of constant pressure (i.e. an isobar).
Closely spaced contours indicate regions where the pressure gradient is large, while regions where the
contours are far apart indicate regions where the pressure gradient is small. Contour maps of atmospheric
3
pressure in the southern hemisphere are shown in (c) a high pressure system, and in (d) a low pressure
system.
Atmospheric Teleconnection Patterns
As we learned in class, there are preferred and persistent patterns of high and low pressure and
winds in the northern hemisphere atmosphere during winter time. The most prominent are the
Pacific North American (PNA) pattern in the North Pacific, and the North Atlantic Oscillation
(NAO) in the North Atlantic.
Question 2:
Figure 2 shows typical pressure anomalies for January in the atmosphere near the top of.
1 ASSIGNMENT #2 Teleconnection Patterns Go to the .docx
1. 1
ASSIGNMENT #2: Teleconnection Patterns
Go to the class web site and download the following files to
your computer:
exercise2_P1.R
exercise2_P2.R
exercise2_P3.R
exercise2_P4.R
pna_all_DJF_1950-2013.dat
pna_warm_DJF_1950-2013.dat
pna_cold_DJF_1950-2013.dat
nao_all_DJF_1950-2013.dat
nao_warm_DJF_1950-2013.dat
nao_cold_DJF_1950-2013.dat
Next, start up “R” and at the prompt (>>) enter your name in the
following way:
name<-“Jane Doe”
2. Important: Be sure to do this before you run each new program.
This step is very important since it will identify you on the
results of your work. If your
name does not appear appropriately on the graphical output that
you hand-in with your
completed assignments, you will receive no credit for this
assignment. In addition, if you
omit this step, the R-programs for this exercise will not work
correctly and you will get an
error message.
Print out and hand in all the figures generated by the programs
for this assignment.
Points for each problem are given as a guide. Though we will
not change these values
typically, we reserve the right to do so as we feel appropriate
and necessary in grading.
Geostrophic Balance and Atmospheric Winds
As we discussed in class, the pressure gradient force and
Coriolis force are generally equal and
opposite in the atmosphere (and ocean) which is referred to as
geostrophic balance. The resulting
winds (and currents) are referred to as geostrophic winds (or
geostrophic currents).
2
3. Question 1:
Figure 1 shows idealized maps of high and low pressure in the
atmosphere in the northern
hemisphere (Figs. 1a and 1b) and in the southern hemisphere
(Figs. 1c and 1d). Each circular line
in Fig. 1 represents a contour of constant of pressure (i.e. an
isobar). In each figure, use arrows to
indicate the direction of the geostrophic winds. Use heavy or
thicker arrows in places where you
expect the winds to be stronger than elsewhere. (12 points)
Figure 1: Contour maps of atmospheric pressure in the northern
hemisphere for (a) a high pressure
system, and (b) a low pressure system. Each contour is a lines
of constant pressure (i.e. an isobar).
Closely spaced contours indicate regions where the pressure
gradient is large, while regions where the
contours are far apart indicate regions where the pressure
gradient is small. Contour maps of atmospheric
3
pressure in the southern hemisphere are shown in (c) a high
pressure system, and in (d) a low pressure
system.
Atmospheric Teleconnection Patterns
4. As we learned in class, there are preferred and persistent
patterns of high and low pressure and
winds in the northern hemisphere atmosphere during winter
time. The most prominent are the
Pacific North American (PNA) pattern in the North Pacific, and
the North Atlantic Oscillation
(NAO) in the North Atlantic.
Question 2:
Figure 2 shows typical pressure anomalies for January in the
atmosphere near the top of the
troposphere that are associated with the PNA pattern and the
NAO. Recall that the 500 mb
geopotential height is the height above the ground at which the
atmospheric pressure is 500 mb.
At this altitude half the mass of the atmosphere is below and
half the mass is above. High and
low pressure systems in the atmosphere lead to undulations in
the time averaged 500 mb
geopotential height. These undulations are referred to as
geopotential anomalies which is what is
shown in Fig. 2. On each panel in Figure 2, indicate the
direction of the geostrophic winds. (4
points)
Figure 2: Maps of January 500mb geopotential height anomalies
near the top of the troposphere
associated with (a) the PNA pattern, and (b) the NAO. For the
purposes of this exercise, you can think of
these as high (H) and low (L) anomalies in atmospheric
pressure.
5. 4
Question 3:
Read pages 69-103 of the class reader, an article entitled “An
Overview of the North Atlantic
Oscillation” by James W. Hurrell, Yochanan Kushnir, Geir
Ottersen and Martin Visbeck (“The
North Atlantic Oscillation: Climatic Significance and
Environmental Impact. Geophysical
Monograph 134. America Geophysical Union, 2003, p1-35).
This article is also available online.
(11 points)
(a) During the positive phase of the NAO, what happens to the
surface temperature over (i)
North America, (ii) Northern Europe and Eurasia, (iii) North
Africa and the Middle East?
(b) During the positive phase of the NAO, what happens to the
North Atlantic storm track?
(c) During the positive phase of the NAO, what happens to
rainfall over (i) Greenland and
the Canadian Arctic, (ii) central and southern Europe and the
Mediterranean, (iii) Iceland,
the British Isles and Scandinavia?
(d) What happens to all of these trends during the negative
phase of the NAO?
6. The Influence of El Niño and La Niña on Atmospheric
Teleconnection Patterns
As we have seen in class, El Niño and La Niña can influence the
preferred phase of the
atmospheric teleconnection patterns.
Question 4:
(a) Run the program “exercise2_P1.R” in R, as you were
instructed to do in class and in
section. This will load the data for the daily average Pacific
North American (PNA) index
for the winter months December, January and February (DJF)
for the period 1950-2013,
and will generate three figures: exercise2_plot1.jpg – the
probability density function
(PDF) of the PNA index for all winters; exercise2_plot2.jpg –
the PDF for the PNA index
for El Niño winters only; and exercise2_plot3.jpg – the PDF for
the PNA index for La
Niña winters only. The data for all winters are called
pna_all_wtr, the data for El Niño
winters only are called pna_el_wtr, and the data for La Niña
winters only are called
pna_la_wtr. (i) Using the “mean” command in R
(“mean(pna_all_wtr)”), compute the
mean of the PNA index for all winters, El Niño winters alone,
and La Niña winters alone.
Write these values on plot 1, 2 or 3 as appropriate. (ii) Briefly
describe how the statistics
of the mean wintertime PNA index are different during El Niño
and La Niña winters (for
7. 5
example, does the PDF differ between the different cases? If
so, in what ways?). (7
points)
(b) Now run the program exercise2_P2.R. This will generate
two additional figures:
exercise2_plot4.jpg – the cumulative probability distribution
function of the DFJ PNA
index during El Niño winters; and exercise2_plot5.jpg – the
cumulative probability
distribution function of the DFJ PNA index during La Niña
winters. (i) Drawing
appropriate horizontal and vertical lines on plot4, estimate the
probability of the PNA
pattern being in its positive phase during El Niño winters and
write this value on plot4.
(ii) Drawing appropriate horizontal and vertical lines on plot5,
estimate the probability of
the PNA pattern being in its positive phase during La Niña
winters and write this
probability on plot5. (iii) Compare these two probabilities with
each other, and compare
the overall impression of these results with your complementary
analysis in (a). (6 points)
Questions 5:
Let’s now explore if the winter time circulation over the North
Atlantic (as described by the
North Atlantic Oscillation (NAO)) varies statistically with El
Niño and La Niña conditions.
8. (a) Run the program exercise2_P3.R in R which will load the
data for the daily average NAO
index for the winter months December, January and February
(DJF) for the period 1950-
2013 and will generate three figures: exercise2_plot6.jpg – the
probability density
function (PDF) of the NAO index for all winters (nao_all_wtr);
exercise2_plot7.jpg – the
PDF for the NAO index for El Niño winters only (nao_el_wtr);
and exercise2_plot8.jpg –
the PDF for the NAO index for La Niña winters only
(nao_la_wtr). (i) Compute the mean
of the NAO index for all winters, El Niño winters alone, and La
Niña winters alone, and
write these values on the appropriate figures. (ii) Briefly
describe if and in what ways the
winter time NAO index statistically changes with El Niño and
La Niña conditions. (4
points)
(b) Now run the program exercise2_P4.R. This will generate
two additional figures:
exercise2_plot9.jpg – the cumulative probability density
function of the DFJ NAO index
during El Niño winters; and exercise2_plot10.jpg – the
cumulative probability density
function of the DFJ NAO index during La Niña winters. (i)
Drawing appropriate
horizontal and vertical lines on plot9, calculate the probability
of the NAO pattern being
in its positive phase during El Niño winters and write the result
on plot9. (ii) Drawing
appropriate horizontal and vertical lines on plot10, calculate the
probability of the NAO
pattern being in its positive phase during La Niña winters and
9. write the result on plot10.
(iii) Compare these two probabilities with each other and
compare the overall impression
they give with your complementary analysis in (a).
6
Question 6:
Based on your findings in questions 4 and 5, briefly comment
on the relative influence of El
Niño and La Niña on the sign of the PNA and NAO patterns
during winter. For example, do El
Niño conditions result in similar changes in the two indices
(relative to all conditions)? Are
changes stronger for one index than for the other? What about
during La Niña? (4 points)
#5
Identify the variables in the study
What is being examined or measured?
For the variables,
provide an operational definition, identify the instruments or
strategies used to collect data on each of the variables,
identify the scale of measurement for the
data related to each variable under examination.-Is this nominal
scale, ordinal scale, interval scale, ratio scale, ratio scale ?
10. WHY ? EXPLAIN remember identify the scale of measure for
the date for each variable there are few don’t just list one..
EXPLAIN
Scale of measurement used pg 56-58
Operational definition 54-55
I have attached several pictures from my textbook that I need to
be referenced in this paper.. please make it simple and easy to
understand and use APA in-text citations
MUST USE THE PICS AS A REFERENCE. IN THE PAPER
PLEASE REFERENCE THE INFO FROM THE PICS AS
JACKSON (2014),
Jackson is the author of the book im using…
#6
For each of the instruments, discuss the data related to the
validity and reliability of each.
In the
pictures attached it discusses the reliability and validity must
cite and source the book … please make this a good response..
Reliability and validity on pages 65+
0.405999988
0.512000024
0.533999979
0.495999992
0.241999999
-0.00899999961
0.133000001
0.239999995
0.064000003
0.143000007
0.342999995
0.204999998
-0.277999997