scholarly journals Relation of glacier variations to climate changes in Iceland

1995 ◽  
Vol 21 ◽  
pp. 263-270 ◽  
Author(s):  
Oddur Sigurdsson ◽  
Trausti Jónsson

Glacier variations in Iceland have been recorded systematically since the 1930s at 27 different glacier termini. The advance/retreat records of non-surging glaciers show a clear relationship to climate. A change in the climate typically leads to a response at the snout within a time period of 10 years. The records of surge-type and mixed-type glaciers show variations that are unrelated to climate. However, the maximum extension of surge-type glaciers at the end of surges and the minimum extension just before a surge appear to be influenced by long-term climate changes. A strong warming in the 1920s was a turning-point in the climate of Iceland which led to a rapid retreat of most glaciers in the country in the 1930s. The summer temperature fell gradually after 1940, with a notable drop in the mid-1960s. Since about 1970, more than half of the glaciers in Iceland have been advancing. In the western part of the country, the recovery is about one-quarter of the ground lost and in the southern, central and northern parts it is about one-half. In southeastern Iceland, some of the glaciers have been stationary for about 30 years while others have advanced slightly. Glacier snow-budget index computed from meteorological data indicates that the timing of the turning-point around 1970 coincides with a minimum in the cumulative net glacier mass balance.

1995 ◽  
Vol 21 ◽  
pp. 263-270 ◽  
Author(s):  
Oddur Sigurdsson ◽  
Trausti Jónsson

Glacier variations in Iceland have been recorded systematically since the 1930s at 27 different glacier termini. The advance/retreat records of non-surging glaciers show a clear relationship to climate. A change in the climate typically leads to a response at the snout within a time period of 10 years. The records of surge-type and mixed-type glaciers show variations that are unrelated to climate. However, the maximum extension of surge-type glaciers at the end of surges and the minimum extension just before a surge appear to be influenced by long-term climate changes. A strong warming in the 1920s was a turning-point in the climate of Iceland which led to a rapid retreat of most glaciers in the country in the 1930s. The summer temperature fell gradually after 1940, with a notable drop in the mid-1960s. Since about 1970, more than half of the glaciers in Iceland have been advancing. In the western part of the country, the recovery is about one-quarter of the ground lost and in the southern, central and northern parts it is about one-half. In southeastern Iceland, some of the glaciers have been stationary for about 30 years while others have advanced slightly. Glacier snow-budget index computed from meteorological data indicates that the timing of the turning-point around 1970 coincides with a minimum in the cumulative net glacier mass balance.


1997 ◽  
Vol 43 (143) ◽  
pp. 131-137 ◽  
Author(s):  
C. Vincent ◽  
M. Vallon

AbstractGlacial mass-balance reconstruction for a long-term time-scale requires knowledge of the relation between climate change and mass-balance fluctuations. A large number of mass-balance reconstructions since the beginning of the century are based on statistical relations between monthly meteorological data and mass balance. The question examined in this paper is: are these relationships reliable enough for long-term time-scale extrapolation? From the glacier de Sarennes long mass-balance observations series, we were surprised to discover large discrepancies between relations resulting from different time periods. The importance of the albedo in relation to ablation and mass balance is highlighted, and it is shown that it is impossible to ignore glacier-surface conditions in establishing the empirical relation between mass-balance fluctuations and climatic variation; to omit this parameter leads to incorrect results for mass-balance reconstruction in the past based on meteorological data.


2011 ◽  
Vol 5 (3) ◽  
pp. 539-549 ◽  
Author(s):  
K. Fujita ◽  
N. Takeuchi ◽  
S. A. Nikitin ◽  
A. B. Surazakov ◽  
S. Okamoto ◽  
...  

Abstract. We conducted 2 yr (2005–2007) of in situ meteorological and glaciological observations on the Gregoriev Glacier, a flat-top glacier within the Inner Tien Shan, Kyrgyzstan. Relative carrier-phase GPS surveys reveal a vertical lowering at the summit of the glacier. Based on snow density data and an energy-mass balance model, we estimate that the annual precipitation and summer mean temperature required to maintain the glacier in the current state are 289 mm and −3.8 °C at the glacier summit (4600 m a.s.l.), respectively. The good agreement between dynamically derived precipitation and the long-term observed precipitation at a nearby station in the Tien Shan (296 mm at 3614 m a.s.l. for the period 1930–2002) suggests that the glacier has been in a near steady-state in terms of mass supply. The glacier mass-balance, reconstructed based on meteorological data from the Tien Shan station for the past 80 yr, explains the observed fluctuations in glacier extent, particularly the negative mass balance in the 1990s.


1990 ◽  
Vol 14 ◽  
pp. 102-106 ◽  
Author(s):  
Jon Ove Hagen ◽  
Olav Liestøl

Mass-balance investigations on glaciers in Svalbard at high latitudes (78°N) show that the ice masses have been steadily decreasing during the period 1950–88. Detailed annual observations have been carried out on Brøggerbreen since 1966 and Lovénbreen since 1967. The mean specific net balances are −0.46 and −0.37 m year−1 water equivalent respectively. Only one year had positive net balance in this period. The cumulative mass lost in the period is then more than 10% of the volume in 1967. Zero net balance would be obtained if the summer temperature was lowered about 1°C or if the winter precipitation increased about 50%. There is a strong correlation between the net mass balance and the height of the equilibrium-line altitude (ELA). Because of the high amount of superimposed ice (10–30% of winter balance) stake readings are necessary to find the ELA. There is no sign of climatic warming through increased melting. The trend analysis of the data from the last 20 years shows stable conditions with a slight increase of the winter balance. The net balance is then slightly increasing and thus less negative than 20 years ago.


2011 ◽  
Vol 5 (2) ◽  
pp. 855-883
Author(s):  
K. Fujita ◽  
N. Takeuchi ◽  
S. A. Nikitin ◽  
A. B. Surazakov ◽  
S. Okamoto ◽  
...  

Abstract. We conducted 2 yr (2005–2007) of in situ meteorological and glaciological observations on the Gregoriev Glacier, a flat-top glacier within the Inner Tien Shan, Kyrgyzstan. Differential GPS surveys reveal a vertical surface deletion at the summit of the glacier. Based on snow density data and an energy-mass balance model, we estimate that the annual precipitation and summer mean temperature required to maintain the glacier in the modern state are 289 mm and −3.85 °C at the glacier summit (4600 m above sea level, a.s.l.), respectively. The good agreement between the long-term estimated and observed precipitation at a nearby station in the Tien Shan (292 mm at 3614 m a.s.l. for the period 1930–2002) suggests that the glacier dynamics have been regulated by the long-term average accumulation. The glacier mass-balance, reconstructed based on meteorological data from the Tien Shan station for the past 80 yr, explains the observed fluctuations in glacier extent, particularly the negative mass balance in the 1990s.


1997 ◽  
Vol 43 (143) ◽  
pp. 131-137 ◽  
Author(s):  
C. Vincent ◽  
M. Vallon

AbstractGlacial mass-balance reconstruction for a long-term time-scale requires knowledge of the relation between climate change and mass-balance fluctuations. A large number of mass-balance reconstructions since the beginning of the century are based on statistical relations between monthly meteorological data and mass balance. The question examined in this paper is: are these relationships reliable enough for long-term time-scale extrapolation? From the glacier de Sarennes long mass-balance observations series, we were surprised to discover large discrepancies between relations resulting from different time periods. The importance of the albedo in relation to ablation and mass balance is highlighted, and it is shown that it is impossible to ignore glacier-surface conditions in establishing the empirical relation between mass-balance fluctuations and climatic variation; to omit this parameter leads to incorrect results for mass-balance reconstruction in the past based on meteorological data.


Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 428
Author(s):  
Sergey O. Grinevskiy ◽  
Sergey P. Pozdniakov ◽  
Ekaterina A. Dedulina

Groundwater recharge by precipitation is the main source of groundwater resources, which are widely used in the European part of Russia (ER). The main goal of the presented studies is to analyze the effect of observed climate changes on the processes of groundwater recharge. For this purpose analysis of long-term meteorological data as well as water budget and groundwater recharge simulation were used. First, meteorological data of 22 weather stations, located from south (Lat 46°) to north (Lat 66°) of ER for historical (1965–1988) and modern (1989–2018) periods were compared to investigate the observed latitudinal changes in annual and seasonal averages of precipitation, wind speed, air temperature, and humidity. Second, water budget in critical zone was simulated, using codes SURFBAL and HYDRUS-1D. SURFBAL generates upper boundary conditions for unsaturated flow modelling with HYDRUS-1D, taking into account snow accumulation and melting as well as topsoil freezing, which are important processes that affect runoff generation and the infiltration of meltwater. Water budget and groundwater recharge simulations based on long-term meteorological data and soil and vegetation parameters, typical for the investigated region. The simulation results for the historical and modern periods were compared to find out the impact of climate change on the average annual and seasonal averages of surface runoff, evapotranspiration, and groundwater recharge, as well as to assess latitudinal differences in water budget changes. The results of the simulation showed, that despite a significant increase in air temperature, groundwater recharge in the southern regions did not change, but even increased up to 50–60 mm/year in the central and northern regions of ER. There are two main reasons for this. First, the observed increase in air temperature is compensated by a decrease in wind speed, so there was no significant increase in evapotranspiration in the modern period. Also, the observed increase in air temperature and precipitation in winter is the main reason for the increase in groundwater recharge, since these climate changes lead to an increase in water infiltration into the soil in the cold period, when there is no evapotranspiration.


2014 ◽  
Vol 13 (1) ◽  
pp. 4058-4067
Author(s):  
Hussain Zaydan Ali ◽  
Salih M. Al-Qaraawi ◽  
Ghusoon Eiden Arab

Global environment change has become a worldwide concern in recent years. Rainfall is an important climatologically parameter, and knowledge of its temporal and spatial patterns is useful for researchers working in many disciplines, such as optimal management of agriculture, environment and related activities. Meteorological data coming from stations are the most reliable and used sources to assess the climate condition of an area. Historical records of monthly rainfall data for the time period 2003-2013 were acquired from the Iraqi Meteorological Organization and Seismology (IMOS). The long-term data were collected from 24 weather stations. To obtain optimal maps of rainfall we also used the Tropical Rainfall Measuring Mission (TRMM). In this paper we tried to explain the possibility of vector format KML and its properties for thematic mapping in Google Earth closer, which is used to display the resulting map outputs. Maps alone are compiled by the client using the Web site browser for transferring input variables to the server, where they are processed and map data is subsequently generated according to client requirements.


1990 ◽  
Vol 14 ◽  
pp. 102-106 ◽  
Author(s):  
Jon Ove Hagen ◽  
Olav Liestøl

Mass-balance investigations on glaciers in Svalbard at high latitudes (78°N) show that the ice masses have been steadily decreasing during the period 1950–88. Detailed annual observations have been carried out on Brøggerbreen since 1966 and Lovénbreen since 1967. The mean specific net balances are −0.46 and −0.37 m year−1 water equivalent respectively. Only one year had positive net balance in this period. The cumulative mass lost in the period is then more than 10% of the volume in 1967. Zero net balance would be obtained if the summer temperature was lowered about 1°C or if the winter precipitation increased about 50%. There is a strong correlation between the net mass balance and the height of the equilibrium-line altitude (ELA). Because of the high amount of superimposed ice (10–30% of winter balance) stake readings are necessary to find the ELA. There is no sign of climatic warming through increased melting. The trend analysis of the data from the last 20 years shows stable conditions with a slight increase of the winter balance. The net balance is then slightly increasing and thus less negative than 20 years ago.


Radiocarbon ◽  
2001 ◽  
Vol 43 (2A) ◽  
pp. 439-447 ◽  
Author(s):  
M G Ogurtsov ◽  
G E Kocharov ◽  
M Lindholm ◽  
M Eronen ◽  
Yu A Nagovitsyn

We performed a statistical analysis of the data on summer temperature anomalies in northern Fennoscandia (8–1995 AD) and found that a 70–130-yr cycle is present in this series during most of the time period. A comparison of the reconstructed northern Fennoscandia temperature with different indicators of solar activity (Wolf numbers, the length of solar Schwabe cycle, extended bi-decadal radiocarbon series, and data on sunspots observed by naked eye) shows that the more probable cause of the periodicity is the modulation of regional northern Fennoscandia climate by the long-term solar cycle of Gleissberg. The effect of this century-scale solar modulation of the global Northern Hemisphere temperature is weaker.


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