Geology Reference
In-Depth Information
(a)
65°North summer half-year insolation
420
400
380
360
340
320
36.
36.5
37
37.5
38.
38.5
39.
39.5
40
(b)
65°North summer half-year insolation+noise
420
400
380
360
340
320
36.
36.5
37
37.5
38.
38.5
39.
39.5
40
(c)
Gauss (0.050 ±0.015)
30
20
10
0
-10
-20
-30
36.
36.5
37
37.5
38.
38.5
39.
39.5
40
(d)
Taner (0.050 ±0.015)
30
20
10
0
-10
-20
-30
36.
36.5
37
37.5
38.
38.5
39.
39.5
40
(e)
Precession index
0.06
0.04
0.0
0
-0.02
-0.04
-0.06
36.
36.5
37
37.5
Millions of years before present
38.
38.5
39.
39.5
40
Figure 4.7
Comparison of Gauss and Taner filter performance in extracting a precession index signal from 65° North
summer half-year insolation (La2004 model; Chapter 5) sampled at Δt = 1 kyr from 36 to 40 Ma. (a) Summer half-year
mean insolation for 65°North, calculated with
Analyseries 2.0.4.
(b) Same as (a) plus white Gaussian noise with variance
equal to that of the insolation. (c) Gauss band-pass filtered series of the precession band insolation. (d) Taner band-pass
filtered series of the precession band insolation. (e) The actual precession index used to compute (a). The applied filters
were defined with the parameters indicated in Figure 4.6. The precession-filtered summer insolation has opposite polarity
to the precession index (see Chapter 5).
