Water Cycle
Or-------------------------~a=r~ba~d~os~I~S·.~
Gough IS./
.I • Valentia
-10
-20
-30
-40
/ -
Dublin
• Copenhagen
61°N Grennedal
700 N scoresbysun. d. ./.' 66°N Angmagssalik
(71~ Goose Bay, Labrador
75°N upepn:7' 71°N Umanak
.",tlsouth Greenland
/"" ,~".""
• 85°5 Horlick Mtns .
• South Pole
-50
Mean annual air temperature (oC)
30
73
Fig. 29 a. Observed b l8 0 concentration in average annual precipitation as a
function of mean annual air temperature. (After DANSGAARD, 1964)
por equilibrium. The atmospheric Rayleigh process also explains why, at
higher altitudes and latitudes, fresh waters become progressively lighter
isotopically, whereas tropical samples show very small depletions relative to ocean water (see Fig. 29 a).
Although the isotopic composition of precipitation at any location
depends on various factors, temperature seems to be the most important
parameter. DANSGAARD (1964) has shown that for marine climates at
medium to high latitudes the 180rO composition of rain averaged over
a whole year varies linearly with the mean annual temperature difference
between the place of evaporation (the tropical ocean) and the place of
deposition. The 180rO composition of averaged rain decreases by 0.7%0
as the temperature difference decreases by 1
0
C.
Seasonal variations of the isotopic composition of rain and snow are
also caused by temperature differences. The £5180-values of rain and
snow at a given locality show a minimum during winter and a maximum
during summer. A good example of the seasonal dependence has been
given by DEUTSCH et al. (1966) on an Austrian glacier, where the mean
M) oscillation between winter and summer snow is 140%0.
Hydrogen and oxygen isotope determinations have provided stimulating and fruitful results in the field of glaciology (EpSTEIN and SHARP,
1959; EpSTEIN et al., 1965, 1970; GONFIANTINI, 1965; DANSGAARD et al.,
Or-------------------------~a=r~ba~d~os~I~S·.~
Gough IS./
.I • Valentia
-10
-20
-30
-40
/ -
Dublin
• Copenhagen
61°N Grennedal
700 N scoresbysun. d. ./.' 66°N Angmagssalik
(71~ Goose Bay, Labrador
75°N upepn:7' 71°N Umanak
.",tlsouth Greenland
/"" ,~".""
• 85°5 Horlick Mtns .
• South Pole
-50
Mean annual air temperature (oC)
30
73
Fig. 29 a. Observed b l8 0 concentration in average annual precipitation as a
function of mean annual air temperature. (After DANSGAARD, 1964)
por equilibrium. The atmospheric Rayleigh process also explains why, at
higher altitudes and latitudes, fresh waters become progressively lighter
isotopically, whereas tropical samples show very small depletions relative to ocean water (see Fig. 29 a).
Although the isotopic composition of precipitation at any location
depends on various factors, temperature seems to be the most important
parameter. DANSGAARD (1964) has shown that for marine climates at
medium to high latitudes the 180rO composition of rain averaged over
a whole year varies linearly with the mean annual temperature difference
between the place of evaporation (the tropical ocean) and the place of
deposition. The 180rO composition of averaged rain decreases by 0.7%0
as the temperature difference decreases by 1
0
C.
Seasonal variations of the isotopic composition of rain and snow are
also caused by temperature differences. The £5180-values of rain and
snow at a given locality show a minimum during winter and a maximum
during summer. A good example of the seasonal dependence has been
given by DEUTSCH et al. (1966) on an Austrian glacier, where the mean
M) oscillation between winter and summer snow is 140%0.
Hydrogen and oxygen isotope determinations have provided stimulating and fruitful results in the field of glaciology (EpSTEIN and SHARP,
1959; EpSTEIN et al., 1965, 1970; GONFIANTINI, 1965; DANSGAARD et al.,