scholarly journals Quantitative Approximation of Mountain Glacial Climates

1990 ◽  
Vol 14 ◽  
pp. 164-167
Author(s):  
William W. Locke

The winter precipitation at the equilibrium line altitude of a wide selection of modern mountain glaciers is well explained (r 2 = 0.81, n = 25) by multiple regression using summer temperature and the logarithm of continentality (distance from a moisture source) as independent variables. Continentality serves as a proxy for inland decreases in energy input through longwave radiation and condensation and increasing energy losses through evaporation and sublimation. Winter precipitation in presently inaccessible areas and former precipitation across broad regions can thus be estimated accurately from two simple variables.

1990 ◽  
Vol 14 ◽  
pp. 164-167
Author(s):  
William W. Locke

The winter precipitation at the equilibrium line altitude of a wide selection of modern mountain glaciers is well explained (r2 = 0.81, n = 25) by multiple regression using summer temperature and the logarithm of continentality (distance from a moisture source) as independent variables. Continentality serves as a proxy for inland decreases in energy input through longwave radiation and condensation and increasing energy losses through evaporation and sublimation. Winter precipitation in presently inaccessible areas and former precipitation across broad regions can thus be estimated accurately from two simple variables.


1988 ◽  
Vol 34 (116) ◽  
pp. 11-18 ◽  
Author(s):  
Anne Letréguilly

AbstractThe mass balance, summer balance, winter balance, and equilibrium-line altitude of three Canadian glaciers (Peyto, Place, and Sentinel Glaciers) are compared with the meteorological records of neighbouring stations for the period 1966—84. While Peyto Glacier’s mass balance is almost entirely related to summer temperature, Sentinel Glacier’s mass balance is mostly controlled by winter precipitation. Place Glacier is influenced by both elements. Statistical reconstructions are presented for the three glaciers, using the best regression equations with the meteorological records since 1938.


1988 ◽  
Vol 34 (116) ◽  
pp. 11-18 ◽  
Author(s):  
Anne Letréguilly

AbstractThe mass balance, summer balance, winter balance, and equilibrium-line altitude of three Canadian glaciers (Peyto, Place, and Sentinel Glaciers) are compared with the meteorological records of neighbouring stations for the period 1966—84. While Peyto Glacier’s mass balance is almost entirely related to summer temperature, Sentinel Glacier’s mass balance is mostly controlled by winter precipitation. Place Glacier is influenced by both elements. Statistical reconstructions are presented for the three glaciers, using the best regression equations with the meteorological records since 1938.


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.


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.


2018 ◽  
Vol 2 (1) ◽  
pp. 140
Author(s):  
Gogor Mustawa Zais

ABSTRACT The objective of this study was to find out and analyze the impact of regional own revenue (PAD), general allocation fund (DAU) and special allocation fund (DAK) on capital expenditure (BM)  in regencies/towns in South  Sumatera Province  for a period of 2010 to 2014. The data were analyzed by using multiple regression. There were four variables in this research. A dependent variable was capital expenditure (BM) and independent variables were regional own revenue (PAD), general allocation fund (DAU) and special allocation fund (DAK). The results showed that the regional own revenue and special allocation fund variables have positive and significant impact on the capital expenditure. This means that the higher the regional own revenue and special allocation fund, the regencies/towns increased the capital expenditure are also higher. General allocation fund do not have a significant effect on the capital expenditure (BM) in regencies/towns in South Sumatera Province for a period of 2010 to 2014


1996 ◽  
Vol 8 (3) ◽  
pp. 133-144 ◽  
Author(s):  
María del Mar del Pozo Andrés ◽  
Jacques F A Braster

In this article we propose two research techniques that can bridge the gap between quantitative and qualitative historical research. These are: (1) a multiple regression approach that gives information about general patterns between numerical variables and the selection of outliers for qualitative analysis; (2) a homogeneity analysis with alternating least squares that results in a two-dimensional picture in which the relationships between categorical variables are graphically presented.


2019 ◽  
Vol 55 (4) ◽  
pp. 2708-2721 ◽  
Author(s):  
S. M. Collins ◽  
S. Yuan ◽  
P. N. Tan ◽  
S. K. Oliver ◽  
J. F. Lapierre ◽  
...  

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1510
Author(s):  
Samuel Henrique Kamphorst ◽  
Gabriel Moreno Bernardo Gonçalves ◽  
Antônio Teixeira do Amaral Júnior ◽  
Valter Jário de Lima ◽  
Kátia Fabiane Medeiros Schmitt ◽  
...  

The identification of traits associated with drought tolerance in popcorn is a contribution to support selection of superior plants under soil water deficit. The objective of this study was to choose morphological traits and the leaf greenness index, measured on different dates, to estimate grain yield (GY) and popping expansion (PE), evaluated in a set of 20 popcorn lines with different genealogies, estimated by multiple regression models. The variables were divided into three groups: morpho-agronomic traits—100-grain weight (GW), prolificacy (PR), tassel length (TL), number of tassel branches, anthesis-silking interval, leaf angle (FA) and leaf rolling (FB); variables related to the intensity of leaf greenness during the grain-filling period, at the leaf level, measured by a portable chlorophyll meter (SPAD) and at the canopy level, calculated as the normalized difference vegetation index (NDVI). The inbred lines were cultivated under two water conditions: well-watered (WW), maintained at field capacity, and water stress (WS), for which irrigation was stopped before male flowering. The traits GY (55%) and PE (28%) were most affected by water restriction. Among the morpho-agronomic traits, GW and PR were markedly reduced (>10%). Under dry conditions, the FA in relation to the plant stalk tended to be wider, the FB curvature greater and leaf senescence accelerated (>15% at 22 days after male flowering). The use of multiple regression for the selection of predictive traits proved to be a useful tool for the identification of groups of adequate traits to efficiently predict the economically most important features of popcorn (GY and PE). The SPAD index measured 17 days after male flowering proved useful to select indirectly for GY, while, among the morphological traits, TL stood out for the same purpose. Of all traits, PR was most strongly related with PE under WS, indicating its use in breeding programs. The exploitation of these traits by indirect selection is expected to induce increments in GY and PE.


1988 ◽  
Vol 32 (17) ◽  
pp. 1179-1182 ◽  
Author(s):  
P. Jay Merkle ◽  
Douglas B. Beaudet ◽  
Robert C. Williges ◽  
David W. Herlong ◽  
Beverly H. Williges

This paper describes a systematic methodology for selecting independent variables to be considered in large-scale research problems. Five specific procedures including brainstorming, prototype interface representation, feasibility/relevance analyses, structured literature reviews, and user subjective ratings are evaluated and incorporated into an integrated strategy. This methodology is demonstrated in the context of designing the user interface for a telephone-based information inquiry system. The procedure was successful in reducing an initial set of 95 independent variables to a subset of 19 factors that warrant subsequent detailed analysis. These results are discussed in terms of a comprehensive sequential research methodology useful for investigating human factors problems.


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