1. North-South Variations in West Coast Hydrometeorological Parameters 15
covered Antarctica and the sea ice surrounding it. Although the ice cover
recedes somewhat during the Southern Hemisphere summer , it does not
undergo the large winter-to-summer changes in area that are experienced
by the snow pack and, to a lesser extent , by the sea ice in the Northern
Hemisphere.
Temperature- Precipitation Trajectories
The variations of temperature and precipitation with latitude were
analyzed to determine how these meteorological parameters could govern
the dominant vegetation types. Figure 1.8 shows the distribution of each
degree of latitude for the western coasts of North and South America as a
function of mean annual temperature and annual precipitation. As noted
earlier, the highest precipitation amounts occur in South America just
north of the equator. According to the climate classification of biomes
developed by MacMahon (1981), also shown in Figure 1.8, these areas
should be dominated by tropical forests . Farther to the south, at latitudes
between 5°Sand 30°S, mean annual temperatures (MATs) range from
20.0°C to IS.0°C, while annual precipitation amounts (APs) range from
omm to 500mm. This would suggest that the desert vegetation types
should dominate over this latitude range. According to Figure 1.3, this
zone is in fact dominated by desert vegetation.
At higher latitudes (45°N to 58°N in North America and 40°S to 55°S
in South America), annual precipitation values range from 2000mm to
- + -TROPICAL FOREST
_ - t o - - +
~" ,
15
'::. : -: -. .
':?:> ..:~::.+--=F::1'- /-__-+
+_--,._-_:~~~F~A~~~P:~~ET:,NDRA
----OECIDUOUS FOREST
- . -DESERT
-f'.-F--I----f---+----= ....... GRASSLAND
30 .0
§: 25.0
(I)
20.0
:;
; 15.0
a.
~
10.0
Iii
5.0
::J
C
0.0
C
oct
c
-5.0
III
(I)
-10.0
::i!:
-15.0 0
500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000
Annual Precipitation (mm)
1""""- North ..+- .. South I
Figure 1.8. Plot of latitudes in a phase space of mean annual temperature and
mean annual precipitation for the study area . A zonation of biome boundaries
based on MacMahon (1981) is added.
covered Antarctica and the sea ice surrounding it. Although the ice cover
recedes somewhat during the Southern Hemisphere summer , it does not
undergo the large winter-to-summer changes in area that are experienced
by the snow pack and, to a lesser extent , by the sea ice in the Northern
Hemisphere.
Temperature- Precipitation Trajectories
The variations of temperature and precipitation with latitude were
analyzed to determine how these meteorological parameters could govern
the dominant vegetation types. Figure 1.8 shows the distribution of each
degree of latitude for the western coasts of North and South America as a
function of mean annual temperature and annual precipitation. As noted
earlier, the highest precipitation amounts occur in South America just
north of the equator. According to the climate classification of biomes
developed by MacMahon (1981), also shown in Figure 1.8, these areas
should be dominated by tropical forests . Farther to the south, at latitudes
between 5°Sand 30°S, mean annual temperatures (MATs) range from
20.0°C to IS.0°C, while annual precipitation amounts (APs) range from
omm to 500mm. This would suggest that the desert vegetation types
should dominate over this latitude range. According to Figure 1.3, this
zone is in fact dominated by desert vegetation.
At higher latitudes (45°N to 58°N in North America and 40°S to 55°S
in South America), annual precipitation values range from 2000mm to
- + -TROPICAL FOREST
_ - t o - - +
~" ,
15
'::. : -: -. .
':?:> ..:~::.+--=F::1'- /-__-+
+_--,._-_:~~~F~A~~~P:~~ET:,NDRA
----OECIDUOUS FOREST
- . -DESERT
-f'.-F--I----f---+----= ....... GRASSLAND
30 .0
§: 25.0
(I)
20.0
:;
; 15.0
a.
~
10.0
Iii
5.0
::J
C
0.0
C
oct
c
-5.0
III
(I)
-10.0
::i!:
-15.0 0
500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000
Annual Precipitation (mm)
1""""- North ..+- .. South I
Figure 1.8. Plot of latitudes in a phase space of mean annual temperature and
mean annual precipitation for the study area . A zonation of biome boundaries
based on MacMahon (1981) is added.