Circulation Types and Their Influence on the Interannual Variability
~
0
+
~
c:
0
+
S
Cf)
0
+
0
4
3
2
0 ..
-1
-2
-3
-4
1958
r
1~ ~
..
. . . ' , •
/ ~ ~i . . .
oJ
• /
~
.
I
1968
.
•
. .
\ . .;.- . ~
\I .-, .
..
1978
YEAR
C + Csw + Cnw + ON
T \
r
• • •
.
oO;'
. .
~ - : (I' .. \,. -
I
oO * ..
.
1988
Winter Precipitation (mm)
.
450
400
Z
350 0
. - 300 ~
0::
(3
- 250
200
150
100
I. 50
1998
W
0:::
a..
0:::
w
r
z
~
231
Fig. 20. Correlation between normalized frequencies of types circulation (C+Csw+Cnw+Cw) and
winter precipitation for Greece (corr. coef.=O.84)
observed when the type C occurs, followed by C sw (S.7mm1day), C NW (4.4mm1day)
and C w (4.1 mm1day).
Figure 18 shows the spatial distribution of winter probability of precipitation per
cyclonic circulation type (Vafiadis et aI., 2000). According to this figure, type C is
associated with a fairly homogeneous high probability distribution of precipitation
almost over the whole country.
The maximum of this probability appears to the west of Peloponesus and the
Ionian Islands, whereas the minimum is found in the north part of Greece. Type C s
shows a rather zonal distribution with the maximum in the south of Greece (Crete)
and the minimum in the north. The type C sw reveals similar distribution with the type
C but with lower values of probability. The type C NW shows a relatively distinct
distribution of probability, especially along the Aegean Sea, as compared to the other
"rainy types" C and C sw . Again the maximum (0.7S) appears in the west but the
minimum is located in Crete. The other cyclonic circulation types present lower
values of probability than the previous types. The two types with eastern location of
the cyclonic centre C NE and C SE show the maximum probability in the south and the
minimum in the north, with the type C SE showing the lowest values among the
cyclonic types. Finally, for the two most marginal types the maximum of probability
are found in the west and the minimum over Crete.
Figure 19 shows the spatial average distribution of the winter precipitation for all
days within each cyclonic type circulation. A clear distinction could be made between
high (C and C sw ), medium (C s , C NW and C w ) and low winter precipitation associated
with the cyclonic types.
In order to further investigate the relationship between precipitation and
~
0
+
~
c:
0
+
S
Cf)
0
+
0
4
3
2
0 ..
-1
-2
-3
-4
1958
r
1~ ~
..
. . . ' , •
/ ~ ~i . . .
oJ
• /
~
.
I
1968
.
•
. .
\ . .;.- . ~
\I .-, .
..
1978
YEAR
C + Csw + Cnw + ON
T \
r
• • •
.
oO;'
. .
~ - : (I' .. \,. -
I
oO * ..
.
1988
Winter Precipitation (mm)
.
450
400
Z
350 0
. - 300 ~
0::
(3
- 250
200
150
100
I. 50
1998
W
0:::
a..
0:::
w
r
z
~
231
Fig. 20. Correlation between normalized frequencies of types circulation (C+Csw+Cnw+Cw) and
winter precipitation for Greece (corr. coef.=O.84)
observed when the type C occurs, followed by C sw (S.7mm1day), C NW (4.4mm1day)
and C w (4.1 mm1day).
Figure 18 shows the spatial distribution of winter probability of precipitation per
cyclonic circulation type (Vafiadis et aI., 2000). According to this figure, type C is
associated with a fairly homogeneous high probability distribution of precipitation
almost over the whole country.
The maximum of this probability appears to the west of Peloponesus and the
Ionian Islands, whereas the minimum is found in the north part of Greece. Type C s
shows a rather zonal distribution with the maximum in the south of Greece (Crete)
and the minimum in the north. The type C sw reveals similar distribution with the type
C but with lower values of probability. The type C NW shows a relatively distinct
distribution of probability, especially along the Aegean Sea, as compared to the other
"rainy types" C and C sw . Again the maximum (0.7S) appears in the west but the
minimum is located in Crete. The other cyclonic circulation types present lower
values of probability than the previous types. The two types with eastern location of
the cyclonic centre C NE and C SE show the maximum probability in the south and the
minimum in the north, with the type C SE showing the lowest values among the
cyclonic types. Finally, for the two most marginal types the maximum of probability
are found in the west and the minimum over Crete.
Figure 19 shows the spatial average distribution of the winter precipitation for all
days within each cyclonic type circulation. A clear distinction could be made between
high (C and C sw ), medium (C s , C NW and C w ) and low winter precipitation associated
with the cyclonic types.
In order to further investigate the relationship between precipitation and