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Chapter 12
Climatic and Geographic Patterns of Spatial
Distribution of Precipitation in Siberia
A. Onuchin and T. Burenina
Abstract
The spatial–temporal distribution of precipitation is a function of atmos-
pheric circulation and the orography of the terrain. Due to these factors the spatial–
temporal distribution of precipitation differs on global, regional and local levels.
Three vast Siberian ecoregions (Western Siberia, Central Siberia and Eastern Siberia)
are differing in their space-temporal patterns of precipitation distribution.
The spatial distribution of precipitation over West Siberia follows a geographical
zonation: precipitation changes from 300 mm in the south to 400–500 mm in the
forest zone. The areas of Central and East Siberia with extreme continental climates
and mountain relief differ in precipitation and moisture characteristics to a great
extent. In Central Siberia precipitation varies between 325 and 525 mm, in East
Siberia between 250 and 330 mm.
Climatic and geographic patterns of the spatial precipitation distribution in
Central Siberia are studied on a regional level. Computer models of spatial precipi-
tation distribution were developed for the Yenisei Mountain Chain, Eastern Sayan,
and the South-eastern Trans-Baikal region.
Owing to irregular spatial distribution of precipitation three groups of landscapes
were defined: (1) slopes of west, north-west and south-west aspect with orographic
precipitation; (2) shadow slopes in mountain regions; (3) plain landscapes. Obtained
equations show correlations between the amount of precipitation and altitude, geo-
graphical latitude, distance from barrier ridge and other parameters.
Keywords
Distribution of precipitation
•
Ecoregion
•
Siberia
•
Spatial precipitation
patterns
•
Geographical zonality
A. Onuchin (
*
) and T. Burenina
V.N. Sukachev Institute of Forest,
SB RAS, Akademgorodok, 50, Krasnoyarsk 660036, Russia
e-mail: onuchin@ksc.krasn.ru; burenina@ksc.krasn.ru
H. Balzter (ed.),
Environmental Change in Siberia: Earth Observation,
Field Studies and Modelling
, Advances in Global Change Research 40,
DOI 10.1007/978-90-481-8641-9_12, © Springer Science+Business Media B.V. 2010
193
194
A. Onuchin and T. Burenina
12.1 Introduction
Atmospheric precipitation is the major moisture circulation component that has a
profound influence on terrestrial ecosystem climate, microclimate, and hydrological
regimes. This explains the numerous studies undertaken to provide a better under-
standing of spatial and temporal precipitation patterns under various vegetation and
climatic conditions (Arkhangelsky
1960
; Berg and Shenrok
1925
; Bradley
1966
;
Burenina et al.
2002
; Glebova
1958
; Gorec and Younkin
1966
; Govsh
1962
;
Kolomyts
1975
; Kopanev
1966
; Matasov
1938
; Matveyev
1968, 1984
; Mellor and
Smith
1966
; Richter and Petrova
1960
; Richter
1963, 1984
; Shpak and Bulavskaya
1967
; Sosedov
1962, 1967
; Tikhomirov
1956
; Trifonova
1962
; Vinogradov
1964
).
Spatial precipitation non-uniformity is most readily apparent in mountains, is attribut-
able to trajectories of air masses within the ocean–land system, distance from the ocean,
atmospheric processes characteristic of different periods of time, and underlying
surface features. According to the current general precipitation scheme, precipitation
increases with increasing elevation and in steadily low-pressure belts, one of which
lies between 60° and 70° N latitude, and decreases with the distance from the ocean.
However, this general scheme contains almost as many exceptions as strong trends.
Precipitation patterns are extremely complicated in mountainous countries. Air
flows occurring around mountain systems and single (separate) elevations enhance
precipitation on windward slopes, while reducing its amount on downwind slopes
(Beyer
1966
; Guralnik et al.
1972
). The outermost upwind slopes, acting as natural
moist air mass breaks, receive more precipitation than those located deeper in moun-
tain systems, even if these in-mountain slopes are higher compared to the outermost
ones (Ladeishchikov
1982
). In this case, precipitation amount is controlled by a num-
ber of factors, such as air mass water content and movement relatively to mountain
“barriers”, thermal layering of the atmosphere, and underlying surface characteristics.
Precipitation is known to vary with elevation above sea level (a.s.l.). In mountains,
precipitation usually increases up to a certain elevation called a peak-moisture zone,
beyond which precipitation stops to increase and can even decrease with elevation
due to decreasing water vapour concentration in the upper atmospheric layers.
These relationships exhibit different behaviour depending on specific orographic
and climatic characteristics of mountainous countries. This dependence was sup-
ported by research studies conducted high in the Alps (Berg
1938
), Pamir-Altai and
the Pamir highland (Kotlyakov
1968
). Among other factors, these differences are
accounted for by foehn, warm and dry wind that occurs in mountains due to down-
draughts found in an atmospheric layer not less than 0.5–1 km deep and promotes
moisture evaporation. The relationship between precipitation amount and topogra-
phy was the focus of a number of studies (Burenina
1998
; Hartzman
1971
; Korytny
1980
; Onuchin
1987
; Onuchin and Burenina
2002
; Shultz
1972
). In closed moun-
tain hollows, precipitation depends on the distance from the surrounding barriers
(Korytny
1980
). Precipitation modelling for upwind slopes breaking the prevailing
atmospheric moisture transfer is a sophisticated process, since it has to consider
many more influences (Onuchin and Burenina
2002
). Where a moisture transfer
12 Climatic and Geographic Patterns of Spatial Distribution of Precipitation in Siberia
195
trajectory coincides with large valley orientation, atmospheric moisture can be
brought to a fairly small region and discharged there through heavy snow or rain-
falls (Suslov
1954
). Although spatial and temporal precipitation patterns are known
to be controlled by numerous landscape-specific factors, precipitation modelling is
usually reduced, with very few exceptions, to interpolating scarce data provided by
a sparse weather station network and assessing the precipitation gradient. The
qualitative trends identified so far for spatial precipitation patterns are still under
considered in development of the quantitative methods adapted to the local condi-
tions of the territory.
Little is known about spatial precipitation distribution in Siberia, with most of
the available publications focusing on spatial precipitation non-uniformity in the
southern Siberian Mountains (Grudinin
1979, 1981
; Lebedev
1979, 1982
).
Mountain range direction, elevation a.s.l. and location with respect to winds carry-
ing moisture are responsible for this non-uniformity. Orographic diversity was the
reason of dividing mountains of southern Siberia into regions differing in annual
precipitation and its vertical gradient (Chebakova
1986
; Grudinin et al.
1975
).
A number of scientists (Afanasyev
1976
; Ladeishchikov
1982
), in their studies of
the precipitation patterns in lake Baikal catchment, noted that the vertical precipita-
tion gradient varied in mountains from 20 to 1,000 mm per 100 m elevation step
depending on the distance from Lake Baikal and the angle between slopes and wet
winds. These factors introduce considerable ambiguity into interpretations of precipi-
tation changes with increasing elevation a.s.l.
Regional and zonal snowfall matches the general macro-scale precipitation
occurrence trends found for Siberia, except that the snow cover distribution is
much more of a mosaic due to numerous influences. Snow cover development
on mountain slopes, under the forest canopy and in open sites, and spatial
snow pack patterns in northern Eurasia were addressed by a number of earlier
studies (Onuchin
1984, 1985, 2001
; Onuchin and Burenina
1996a, b
). Since
snow cover development requires an extended separate discussion, we leave it
outside the scope of this chapter and focus on general spatial precipitation
trends in Siberia.
12.2 Study Area and Methods
Siberia stretches from the Ural Mountains eastward as far as the Lena river and
includes the West Siberian Plain, Central Siberian Tableland, the watershed of Lena
river, the Altai-Sayan mountain range, and the Lake Baikal region. Our study area
covered the territory from 50° to 70° N latitude and from 60º to 160° E longitude.
Our ground truth data were obtained in the Putoran Plateau, Yenisei Mountain
Chain, north-eastern and central Siberia respectively (Fig.
12.1
), south-western
Siberia, Eastern Sayan, and the south-eastern Trans-Baikal region. The study sites
thus covered the entire range of Siberian vegetation zones, from tundra to steppe
and all altitudinal vegetation zones in mountains.
196
A. Onuchin and T. Burenina
Fig. 12.1
Location of points of snow precipitation measurements in Central Siberia.
Dots
are
points of snow precipitation measurement; the scale is altitude (m)
The precipitation distribution was investigated at ecoregional
1
and local levels.
In the latter case, spatial precipitation models were developed for different areas
within ecoregions accounting for local orography and air mass circulation. Macro-
scale (i.e. ecoregional) precipitation distribution was analyzed using weather data
provided by 130 weather stations situated in the study area (USSR Climate Guide
1956, 1969, 1970
). Weighted average annual precipitation was calculated by spatially
averaging for each study area (forest provinces or forest districts according to the
current Russian forest regionalization by Korotkov (
1994
)).
Siberia is remarkable for contrasting natural conditions; its weather station
network is highly irregular, and particularly sparse in the north. Therefore, one of
the most reliable methods to obtain average precipitation for an area involves build-
ing average precipitation isoclines and measuring areas between pairs of adjacent
isoclines by planometric techniques (Schwer
1984
). Average precipitation values
were calculated for the ecoregions of interest by the following equation:
S
FF
m
+
F
=×
∑
k
k
+
1
(12.1)
s
S
2
1
where S
k
is area between a pair of isolines corresponding to F
k
1
Ecoregion refers to a big area identified based on a landscape approach. Ecoregion examples in
Siberia are West-Siberian Plain, Central Siberian table land, and Altai-Sayan mountain system.
Ecoregional boundaries coincide with those of forest oblasts as identified by Korotkov (
1994
).
k
12 Climatic and Geographic Patterns of Spatial Distribution of Precipitation in Siberia
197
and F
k + 1
average precipitation values, m is the number of these areas, and S is the
entire area for which averaging is done.
Local precipitation distribution was calculated based on weather station infor-
mation combined with our in situ precipitation measurements. The data obtained
were subjected to multiple regression analysis (Lvovsky
1988
).
12.3 Results
12.3.1 Spatial Precipitation Patterns in Siberian Ecoregions
The interactions of the atmosphere with the underlying land surface, with the
former being dynamic in time and the latter having noticeable spatial variabil-
ity, are responsible for precipitation development and, hence, its spatial and
temporal patterns.
Atmospheric precipitation is a key moisture cycling component which controls
hydrological regimes of terrestrial ecosystems to a great extent. Precipitation pat-
tern is a major factor accounting for landscape differentiation. The precipitation
amount varies, in turn, depending on regional atmospheric circulation and underlying
surface characteristics.
Geographical contrasts of Siberia are reflected in both latitudinal and meridian
precipitation occurrence in this region. For this reason, it is most appropriate to
analyze macro-scale precipitation distribution based on large ecoregions. According
to the current Russian forest regionalization (Korotkov
1994
), eight forest regions
(defined as “ecoregions”) found in Siberia contain 32 forest provinces, which are
divided into subprovinces (or forest districts) (Fig.
12.2
). This forest regionaliza-
tion considers precipitation amount by latitude and continentality. Table
12.1
shows
the spatial distribution of precipitation for forest provinces and forest districts inside
of large Siberian ecoregions. The numbers of forest provinces and districts in
Table
12.1
are given according to Fig.
12.2
.
A latitudinal precipitation change characteristic of the West Siberian Plain is
manifest in the decreasing precipitation amounts proceeding south and northward
from the taiga forest provinces. Precipitation is fairly high (505–508 mm) in the
northern and southern taiga, while it decreases further to the north and averages only
378 mm in the north of the Trans-Ural-Yenisei province, which is actually forest-
tundra. The lowest precipitation (296 mm) was found for the Kulunda province
situated in the steppe zone.
Precipitation tends to decrease west-eastward in eastern Siberia. The western part
of the Central Siberian tableland can be considered as a transition to the dry continental
climate of eastern Siberia. While the maximum annual precipitation (617–675 mm)
was found to occur in the Putoran and Yenisei forest provinces, the Anabar province
and Kotuy-Olenek forest district received the lowest amount of precipitation
(325–342 mm). The non-uniform precipitation distribution found within the western
part of the Central Siberian tableland is most probably caused by its orography.
zanotowane.pl doc.pisz.pl pdf.pisz.pl hannaeva.xlx.pl
Climatic and Geographic Patterns of Spatial
Distribution of Precipitation in Siberia
A. Onuchin and T. Burenina
Abstract
The spatial–temporal distribution of precipitation is a function of atmos-
pheric circulation and the orography of the terrain. Due to these factors the spatial–
temporal distribution of precipitation differs on global, regional and local levels.
Three vast Siberian ecoregions (Western Siberia, Central Siberia and Eastern Siberia)
are differing in their space-temporal patterns of precipitation distribution.
The spatial distribution of precipitation over West Siberia follows a geographical
zonation: precipitation changes from 300 mm in the south to 400–500 mm in the
forest zone. The areas of Central and East Siberia with extreme continental climates
and mountain relief differ in precipitation and moisture characteristics to a great
extent. In Central Siberia precipitation varies between 325 and 525 mm, in East
Siberia between 250 and 330 mm.
Climatic and geographic patterns of the spatial precipitation distribution in
Central Siberia are studied on a regional level. Computer models of spatial precipi-
tation distribution were developed for the Yenisei Mountain Chain, Eastern Sayan,
and the South-eastern Trans-Baikal region.
Owing to irregular spatial distribution of precipitation three groups of landscapes
were defined: (1) slopes of west, north-west and south-west aspect with orographic
precipitation; (2) shadow slopes in mountain regions; (3) plain landscapes. Obtained
equations show correlations between the amount of precipitation and altitude, geo-
graphical latitude, distance from barrier ridge and other parameters.
Keywords
Distribution of precipitation
•
Ecoregion
•
Siberia
•
Spatial precipitation
patterns
•
Geographical zonality
A. Onuchin (
*
) and T. Burenina
V.N. Sukachev Institute of Forest,
SB RAS, Akademgorodok, 50, Krasnoyarsk 660036, Russia
e-mail: onuchin@ksc.krasn.ru; burenina@ksc.krasn.ru
H. Balzter (ed.),
Environmental Change in Siberia: Earth Observation,
Field Studies and Modelling
, Advances in Global Change Research 40,
DOI 10.1007/978-90-481-8641-9_12, © Springer Science+Business Media B.V. 2010
193
194
A. Onuchin and T. Burenina
12.1 Introduction
Atmospheric precipitation is the major moisture circulation component that has a
profound influence on terrestrial ecosystem climate, microclimate, and hydrological
regimes. This explains the numerous studies undertaken to provide a better under-
standing of spatial and temporal precipitation patterns under various vegetation and
climatic conditions (Arkhangelsky
1960
; Berg and Shenrok
1925
; Bradley
1966
;
Burenina et al.
2002
; Glebova
1958
; Gorec and Younkin
1966
; Govsh
1962
;
Kolomyts
1975
; Kopanev
1966
; Matasov
1938
; Matveyev
1968, 1984
; Mellor and
Smith
1966
; Richter and Petrova
1960
; Richter
1963, 1984
; Shpak and Bulavskaya
1967
; Sosedov
1962, 1967
; Tikhomirov
1956
; Trifonova
1962
; Vinogradov
1964
).
Spatial precipitation non-uniformity is most readily apparent in mountains, is attribut-
able to trajectories of air masses within the ocean–land system, distance from the ocean,
atmospheric processes characteristic of different periods of time, and underlying
surface features. According to the current general precipitation scheme, precipitation
increases with increasing elevation and in steadily low-pressure belts, one of which
lies between 60° and 70° N latitude, and decreases with the distance from the ocean.
However, this general scheme contains almost as many exceptions as strong trends.
Precipitation patterns are extremely complicated in mountainous countries. Air
flows occurring around mountain systems and single (separate) elevations enhance
precipitation on windward slopes, while reducing its amount on downwind slopes
(Beyer
1966
; Guralnik et al.
1972
). The outermost upwind slopes, acting as natural
moist air mass breaks, receive more precipitation than those located deeper in moun-
tain systems, even if these in-mountain slopes are higher compared to the outermost
ones (Ladeishchikov
1982
). In this case, precipitation amount is controlled by a num-
ber of factors, such as air mass water content and movement relatively to mountain
“barriers”, thermal layering of the atmosphere, and underlying surface characteristics.
Precipitation is known to vary with elevation above sea level (a.s.l.). In mountains,
precipitation usually increases up to a certain elevation called a peak-moisture zone,
beyond which precipitation stops to increase and can even decrease with elevation
due to decreasing water vapour concentration in the upper atmospheric layers.
These relationships exhibit different behaviour depending on specific orographic
and climatic characteristics of mountainous countries. This dependence was sup-
ported by research studies conducted high in the Alps (Berg
1938
), Pamir-Altai and
the Pamir highland (Kotlyakov
1968
). Among other factors, these differences are
accounted for by foehn, warm and dry wind that occurs in mountains due to down-
draughts found in an atmospheric layer not less than 0.5–1 km deep and promotes
moisture evaporation. The relationship between precipitation amount and topogra-
phy was the focus of a number of studies (Burenina
1998
; Hartzman
1971
; Korytny
1980
; Onuchin
1987
; Onuchin and Burenina
2002
; Shultz
1972
). In closed moun-
tain hollows, precipitation depends on the distance from the surrounding barriers
(Korytny
1980
). Precipitation modelling for upwind slopes breaking the prevailing
atmospheric moisture transfer is a sophisticated process, since it has to consider
many more influences (Onuchin and Burenina
2002
). Where a moisture transfer
12 Climatic and Geographic Patterns of Spatial Distribution of Precipitation in Siberia
195
trajectory coincides with large valley orientation, atmospheric moisture can be
brought to a fairly small region and discharged there through heavy snow or rain-
falls (Suslov
1954
). Although spatial and temporal precipitation patterns are known
to be controlled by numerous landscape-specific factors, precipitation modelling is
usually reduced, with very few exceptions, to interpolating scarce data provided by
a sparse weather station network and assessing the precipitation gradient. The
qualitative trends identified so far for spatial precipitation patterns are still under
considered in development of the quantitative methods adapted to the local condi-
tions of the territory.
Little is known about spatial precipitation distribution in Siberia, with most of
the available publications focusing on spatial precipitation non-uniformity in the
southern Siberian Mountains (Grudinin
1979, 1981
; Lebedev
1979, 1982
).
Mountain range direction, elevation a.s.l. and location with respect to winds carry-
ing moisture are responsible for this non-uniformity. Orographic diversity was the
reason of dividing mountains of southern Siberia into regions differing in annual
precipitation and its vertical gradient (Chebakova
1986
; Grudinin et al.
1975
).
A number of scientists (Afanasyev
1976
; Ladeishchikov
1982
), in their studies of
the precipitation patterns in lake Baikal catchment, noted that the vertical precipita-
tion gradient varied in mountains from 20 to 1,000 mm per 100 m elevation step
depending on the distance from Lake Baikal and the angle between slopes and wet
winds. These factors introduce considerable ambiguity into interpretations of precipi-
tation changes with increasing elevation a.s.l.
Regional and zonal snowfall matches the general macro-scale precipitation
occurrence trends found for Siberia, except that the snow cover distribution is
much more of a mosaic due to numerous influences. Snow cover development
on mountain slopes, under the forest canopy and in open sites, and spatial
snow pack patterns in northern Eurasia were addressed by a number of earlier
studies (Onuchin
1984, 1985, 2001
; Onuchin and Burenina
1996a, b
). Since
snow cover development requires an extended separate discussion, we leave it
outside the scope of this chapter and focus on general spatial precipitation
trends in Siberia.
12.2 Study Area and Methods
Siberia stretches from the Ural Mountains eastward as far as the Lena river and
includes the West Siberian Plain, Central Siberian Tableland, the watershed of Lena
river, the Altai-Sayan mountain range, and the Lake Baikal region. Our study area
covered the territory from 50° to 70° N latitude and from 60º to 160° E longitude.
Our ground truth data were obtained in the Putoran Plateau, Yenisei Mountain
Chain, north-eastern and central Siberia respectively (Fig.
12.1
), south-western
Siberia, Eastern Sayan, and the south-eastern Trans-Baikal region. The study sites
thus covered the entire range of Siberian vegetation zones, from tundra to steppe
and all altitudinal vegetation zones in mountains.
196
A. Onuchin and T. Burenina
Fig. 12.1
Location of points of snow precipitation measurements in Central Siberia.
Dots
are
points of snow precipitation measurement; the scale is altitude (m)
The precipitation distribution was investigated at ecoregional
1
and local levels.
In the latter case, spatial precipitation models were developed for different areas
within ecoregions accounting for local orography and air mass circulation. Macro-
scale (i.e. ecoregional) precipitation distribution was analyzed using weather data
provided by 130 weather stations situated in the study area (USSR Climate Guide
1956, 1969, 1970
). Weighted average annual precipitation was calculated by spatially
averaging for each study area (forest provinces or forest districts according to the
current Russian forest regionalization by Korotkov (
1994
)).
Siberia is remarkable for contrasting natural conditions; its weather station
network is highly irregular, and particularly sparse in the north. Therefore, one of
the most reliable methods to obtain average precipitation for an area involves build-
ing average precipitation isoclines and measuring areas between pairs of adjacent
isoclines by planometric techniques (Schwer
1984
). Average precipitation values
were calculated for the ecoregions of interest by the following equation:
S
FF
m
+
F
=×
∑
k
k
+
1
(12.1)
s
S
2
1
where S
k
is area between a pair of isolines corresponding to F
k
1
Ecoregion refers to a big area identified based on a landscape approach. Ecoregion examples in
Siberia are West-Siberian Plain, Central Siberian table land, and Altai-Sayan mountain system.
Ecoregional boundaries coincide with those of forest oblasts as identified by Korotkov (
1994
).
k
12 Climatic and Geographic Patterns of Spatial Distribution of Precipitation in Siberia
197
and F
k + 1
average precipitation values, m is the number of these areas, and S is the
entire area for which averaging is done.
Local precipitation distribution was calculated based on weather station infor-
mation combined with our in situ precipitation measurements. The data obtained
were subjected to multiple regression analysis (Lvovsky
1988
).
12.3 Results
12.3.1 Spatial Precipitation Patterns in Siberian Ecoregions
The interactions of the atmosphere with the underlying land surface, with the
former being dynamic in time and the latter having noticeable spatial variabil-
ity, are responsible for precipitation development and, hence, its spatial and
temporal patterns.
Atmospheric precipitation is a key moisture cycling component which controls
hydrological regimes of terrestrial ecosystems to a great extent. Precipitation pat-
tern is a major factor accounting for landscape differentiation. The precipitation
amount varies, in turn, depending on regional atmospheric circulation and underlying
surface characteristics.
Geographical contrasts of Siberia are reflected in both latitudinal and meridian
precipitation occurrence in this region. For this reason, it is most appropriate to
analyze macro-scale precipitation distribution based on large ecoregions. According
to the current Russian forest regionalization (Korotkov
1994
), eight forest regions
(defined as “ecoregions”) found in Siberia contain 32 forest provinces, which are
divided into subprovinces (or forest districts) (Fig.
12.2
). This forest regionaliza-
tion considers precipitation amount by latitude and continentality. Table
12.1
shows
the spatial distribution of precipitation for forest provinces and forest districts inside
of large Siberian ecoregions. The numbers of forest provinces and districts in
Table
12.1
are given according to Fig.
12.2
.
A latitudinal precipitation change characteristic of the West Siberian Plain is
manifest in the decreasing precipitation amounts proceeding south and northward
from the taiga forest provinces. Precipitation is fairly high (505–508 mm) in the
northern and southern taiga, while it decreases further to the north and averages only
378 mm in the north of the Trans-Ural-Yenisei province, which is actually forest-
tundra. The lowest precipitation (296 mm) was found for the Kulunda province
situated in the steppe zone.
Precipitation tends to decrease west-eastward in eastern Siberia. The western part
of the Central Siberian tableland can be considered as a transition to the dry continental
climate of eastern Siberia. While the maximum annual precipitation (617–675 mm)
was found to occur in the Putoran and Yenisei forest provinces, the Anabar province
and Kotuy-Olenek forest district received the lowest amount of precipitation
(325–342 mm). The non-uniform precipitation distribution found within the western
part of the Central Siberian tableland is most probably caused by its orography.