scholarly journals Glacier volume response time and its links to climate and topography based on a conceptual model of glacier hypsometry

2009 ◽  
Vol 3 (2) ◽  
pp. 183-194 ◽  
Author(s):  
S. C. B. Raper ◽  
R. J. Braithwaite
Keyword(s):  
Response Time ◽  
Mass Balance ◽  
Conceptual Model ◽  
Response Times ◽  
Climate Modelling ◽  
Scaling Relation ◽  
Glacier Terminus ◽  
Volume Response ◽  
Southern Norway ◽  
Simple Ratio

Abstract. Glacier volume response time is a measure of the time taken for a glacier to adjust its geometry to a climate change. It has been previously proposed that the volume response time is given approximately by the ratio of glacier thickness to ablation at the glacier terminus. We propose a new conceptual model of glacier hypsometry (area-altitude relation) and derive the volume response time where climatic and topographic parameters are separated. The former is expressed by mass balance gradients which we derive from glacier-climate modelling and the latter are quantified with data from the World Glacier Inventory. Aside from the well-known scaling relation between glacier volume and area, we establish a new scaling relation between glacier altitude range and area, and evaluate it for seven regions. The presence of this scaling parameter in our response time formula accounts for the mass balance elevation feedback and leads to longer response times than given by the simple ratio of glacier thickness to ablation at the terminus. Volume response times range from decades to thousands of years for glaciers in maritime (wet-warm) and continental (dry-cold) climates respectively. The combined effect of volume-area and altitude-area scaling relations is such that volume response time can increase with glacier area (Axel Heiberg Island and Svalbard), hardly change (Northern Scandinavia, Southern Norway and the Alps) or even get smaller (The Caucasus and New Zealand).

scholarly journals Glacier volume response time and its links to climate and topography based on a conceptual model of glacier hypsometry

2009 ◽  
Vol 3 (1) ◽  
pp. 243-275 ◽  
Author(s):  
S. C. B. Raper ◽  
R. J. Braithwaite
Keyword(s):  
Response Time ◽  
Mass Balance ◽  
Conceptual Model ◽  
Response Times ◽  
Climate Modelling ◽  
Scaling Relation ◽  
Ablation Volume ◽  
Glacier Terminus ◽  
Volume Response ◽  
Simple Ratio

Abstract. Glacier volume response time is a measure of the time taken for a glacier to adjust its geometry to a climate change. It is currently believed that the volume response time is given approximately by the ratio of glacier thickness to ablation at the glacier terminus. We propose a new conceptual model of glacier hypsometry (area-altitude relation) and derive the volume response time where climatic and topographic parameters are separated. The former is expressed by mass balance gradients which we derive from glacier-climate modelling and the latter are quantified with data from the World Glacier Inventory. Aside from the well-known scaling relation between glacier volume and area, we establish a new scaling relation between glacier altitude range and area, and evaluate it for seven regions. The presence of this scaling parameter in our response time formula accounts for the mass balance elevation feedback and leads to longer response times than given by the simple ratio of glacier thickness to ablation. Volume response times range from decades to thousands of years for glaciers in maritime (wet-warm) and continental (dry-cold) climates, respectively. The combined effect of volume-area and altitude-area scaling relations is such that volume response time can increase with glacier area (Axel Heiberg Island and Svalbard), hardly change (Northern Scandinavia, Southern Norway and the Alps) or even get smaller (The Caucasus and New Zealand).

scholarly journals On the climate–geometry imbalance, response time and volume–area scaling of an alpine glacier: insights from a 3-D flow model applied to Vadret da Morteratsch, Switzerland

2015 ◽  
Vol 56 (70) ◽  
pp. 51-62 ◽  
Author(s):  
H. Zekollari ◽  
P. Huybrechts
Keyword(s):  
Response Time ◽  
Mass Balance ◽  
Flow Model ◽  
Response Times ◽  
Three Dimensional ◽  
Transient State ◽  
Balance Model ◽  
Surface Mass ◽  
Alpine Glacier ◽  
Volume Response

AbstractA two-dimensional surface mass-balance model is coupled to a three-dimensional higher-order ice flow model to assess the imbalance between climate and glacier geometry for the Morteratsch (Engadine, Switzerland) glacier complex. The climate–geometry imbalance has never been larger than at present, indicating that the temperature increase is faster than the geometry is able to adapt to. We derive response times from transient and steady-state geometries and find that the volume response time is correlated to the magnitude of the mass-balance forcing. It varies between 22 and 43 years, while the length response time is between 47 and 55 years. Subsequently, the modelled response times are compared with different analytical methods from the literature. The effect of a climatic perturbation on the response time, which produces a spatially distributed mass-balance forcing, is also examined. We investigate the effect of glacier size on the response time and project that the response time will decrease in the future due to a surface steepening. Finally, volume–area scaling methods with different parameters are tested and an alternative method is proposed that takes into account the surface slope. The effect of a transient state on the method is also evaluated.

scholarly journals Characteristic mass-balance scaling with valley glacier size

1999 ◽  
Vol 45 (149) ◽  
pp. 17-21 ◽  
Author(s):  
David B. Bahr ◽  
Mark Dyurgerov
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Scaling Exponent ◽  
Scaling Relation ◽  
Glacier Recession ◽  
Glacier Terminus ◽  
Valley Glacier ◽  
Glacier Length ◽  
The Impact ◽  
Characteristic Mass

AbstractPrevious work on the relation between glacier volume and area and on accumulation area ratios suggests that balance rates measured at the glacier terminus are not constant or random from glacier to glacier but instead scale with glacier length. Using mass-balance data from a collection of 68 valley and cirque glaciers, we show that the terminus mass-balance rate scales roughly linearly with surface area and scales with length raised to an exponent constrained to fall roughly between 0.5 and 2 with 1.7 preferred if a glacier’s length is dependent on the mass-balance conditions (rather than balance being dependent on length). When these exponents are used to predict valley-glacier volume–area scaling, the results are very close to empirical volume–area observations. Although the data are noisy and the proposed fits could be modified by improved observations, the scaling trend for terminus balance vs length remains clear. Although the exact value of the scaling exponent is not well determined, establishing the existence of this scaling relation will be important for studies of climate change and the impact of glacier recession on sea level.

scholarly journals Characteristic mass-balance scaling with valley glacier size

1999 ◽  
Vol 45 (149) ◽  
pp. 17-21
Author(s):  
David B. Bahr ◽  
Mark Dyurgerov
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Scaling Exponent ◽  
Scaling Relation ◽  
Glacier Recession ◽  
Glacier Terminus ◽  
Valley Glacier ◽  
Glacier Length ◽  
The Impact ◽  
Characteristic Mass

Abstract Previous work on the relation between glacier volume and area and on accumulation area ratios suggests that balance rates measured at the glacier terminus are not constant or random from glacier to glacier but instead scale with glacier length. Using mass-balance data from a collection of 68 valley and cirque glaciers, we show that the terminus mass-balance rate scales roughly linearly with surface area and scales with length raised to an exponent constrained to fall roughly between 0.5 and 2 with 1.7 preferred if a glacier’s length is dependent on the mass-balance conditions (rather than balance being dependent on length). When these exponents are used to predict valley-glacier volume–area scaling, the results are very close to empirical volume–area observations. Although the data are noisy and the proposed fits could be modified by improved observations, the scaling trend for terminus balance vs length remains clear. Although the exact value of the scaling exponent is not well determined, establishing the existence of this scaling relation will be important for studies of climate change and the impact of glacier recession on sea level.

scholarly journals Stimulus-response time to invasive blood pressure alarms: implications for the safety of critical-care patients

2014 ◽  
Vol 35 (2) ◽  
pp. 135-141 ◽  
Author(s):  
Adele Kuckartz Pergher ◽  
Roberto Carlos Lyra da Silva
Keyword(s):  
Blood Pressure ◽  
Response Time ◽  
Response Times ◽  
Hemodynamic Instability ◽  
Military Hospital ◽  
Invasive Blood Pressure ◽  
Stimulus Response ◽  
The City ◽  
Physical Layout

Observational, descriptive, exploratory, case study with the objective of measuring the stimulus-response time of the team to alarms monitoring invasive blood pressure (IBP) and analyzing the implications of this time for the safety of the patient. From January to March 2013, 60 hours of structured observation were conducted with registration of the alarms activated by IBP monitors in an adult ICU at a military hospital in the city of Rio de Janeiro. 76 IBP alarms were recorded (1.26 alarms/hour), 21 of which (28%) were attended to and 55 (72%) considered as fatigued. The average response time to the alarms was 2 min. 45 sec. The deficit in human resource and physical layout were factors determining the delay in response to the alarms. The increase in response times to these alarms may compromise the safety of patients with hemodynamic instability, especially in situations such as shock and the use of vasoactive drugs.

scholarly journals Sensitivities of glacier mass balance and runoff to climate perturbations in Norway

2015 ◽  
Vol 56 (70) ◽  
pp. 79-88 ◽  
Author(s):  
Markus Engelhardt ◽  
Thomas V. Schuler ◽  
Liss M. Andreassen
Keyword(s):  
Mass Balance ◽  
Temperature Change ◽  
Air Temperature ◽  
Annual Runoff ◽  
Precipitation Change ◽  
Glacier Mass Balance ◽  
Northern Norway ◽  
Temperature Range ◽  
Temperature And Precipitation ◽  
Southern Norway

AbstractThis study evaluates sensitivities of glacier mass balance and runoff to both annual and monthly perturbations in air temperature and precipitation at four highly glacierized catchments: Engabreen in northern Norway and Ålfotbreen, Nigardsbreen and Storbreen, which are aligned along a west–east profile in southern Norway. The glacier mass-balance sensitivities to changes in annual air temperature range from 1.74 m w.e. K−1 for Ålfotbreen to 0.55 m w.e. K−1 for Storbreen, the most maritime and the most continental glaciers in this study, respectively. The runoff sensitivities of all catchments are 20–25% per degree temperature change and 6–18% for a 30% precipitation change. A seasonality of the sensitivities becomes apparent. With increasing continentality, the sensitivity of mass balance and runoff to temperature perturbations during summer increases, and the sensitivity of annual runoff to both temperature and precipitation perturbations is constricted towards changes during the ablation period. Comparing sensitivities in northern and southern Norway, as well as the variability across southern Norway, reveals that continentality influences sensitivities more than latitude does.

scholarly journals English Speakers’ Implicit Gender Concepts Influence Their Processing of French Grammatical Gender: Evidence for Semantically Mediated Cross-Linguistic Influence

2021 ◽  
Vol 12 ◽  
Author(s):  
Elena Nicoladis ◽  
Chris Westbury ◽  
Cassandra Foursha-Stevenson
Keyword(s):  
Second Language ◽  
Response Time ◽  
Response Times ◽  
First Language ◽  
Grammatical Gender ◽  
Word Embedding ◽  
English Speakers ◽  
French Words ◽  
L1 English ◽  
French Gender

Second language (L2) learners often show influence from their first language (L1) in all domains of language. This cross-linguistic influence could, in some cases, be mediated by semantics. The purpose of the present study was to test whether implicit English gender connotations affect L1 English speakers’ judgments of the L2 French gender of objects. We hypothesized that gender estimates derived from word embedding models that measure similarity of word contexts in English would affect accuracy and response time on grammatical gender (GG) decision in L2 French. L2 French learners were asked to identify the GG of French words estimated to be either congruent or incongruent with the implicit gender in English. The results showed that they were more accurate with words that were congruent with English gender connotations than words that were incongruent, suggesting that English gender connotations can influence grammatical judgments in French. Response times showed the same pattern. The results are consistent with semantics-mediated cross-linguistic influence.

scholarly journals A High-Stakes Approach to Response Time Effort in Low-Stakes Assessment

2021 ◽  
Vol 7 (4) ◽  
pp. 571-586
Author(s):  
Munevver Ilgun
Keyword(s):  
Response Time ◽  
Failure Time ◽  
Response Times ◽  
Survival Models ◽  
Accelerated Failure Time ◽  
Data Sets ◽  
High Stakes ◽  
Problem Solving Skills ◽  
Educational Stakeholders ◽  
Accelerated Failure Time Models

<p style="text-align: justify;">Response times are one of the important sources that provide information about the performance of individuals during a test process. The main purpose of this study is to show that survival models can be used in educational data. Accordingly, data sets of items measuring literacy, numeracy and problem-solving skills of the countries participating in Round 3 of the Programme for the International Assessment of Adult Competencies were used. Accelerated failure time models have been analyzed for each country and domain.  As a result of the analysis of the models in which various covariates are included as independent variables, and response time for giving correct answers is included as a dependent variable, it was found the associations between the covariates and response time for giving correct answers were concluded to vary from one domain to another or from one country to another. The results obtained from the present study have provided the educational stakeholders and practitioners with valuable information.</p>

scholarly journals A comparison of different methods of evaluating glacier response characteristics: application to glacier AX010, Nepal Himalaya

2009 ◽  
Vol 3 (3) ◽  
pp. 765-804 ◽  
Author(s):  
S. Adhikari ◽  
S. J. Marshall ◽  
P. Huybrechts
Keyword(s):  
Response Time ◽  
Flow Model ◽  
Ice Flow ◽  
Nepal Himalaya ◽  
Response Characteristics ◽  
Response Behaviour ◽  
Himalayan Glaciers ◽  
Valley Glacier ◽  
Volume Response ◽  
Small Valley

Abstract. Himalayan glaciers are considered to be amongst the most sensitive glaciers to climate change. However, the response behaviour of these glaciers is not well understood. Here we use several approaches to estimate characteristic timescales of glacier AX010, a small valley glacier in the Nepal Himalaya, as a measure of glacier sensitivity. Assuming that temperature solely defines the mass budget, glacier AX010 waits for about 8 yr (reaction time) to exhibit its initial terminus response to changing climate. On the other hand, it takes between 29–56 yr (volume response time) and 37–70 yr (length response time) to adjust its volume and length following the changes in mass balance conditions, respectively. A numerical ice-flow model, the only method that yields both length and volume response time, confirms that a glacier takes longer to adjust its length than its volume.

scholarly journals Response Time Distribution Analysis of Semantic and Response Interference in a Manual Response Stroop Task

2019 ◽  
Vol 66 (3) ◽  
pp. 231-238 ◽  
Author(s):  
Nabil Hasshim ◽  
Michelle Downes ◽  
Sarah Bate ◽  
Benjamin A. Parris
Keyword(s):  
Response Time ◽  
Stroop Task ◽  
Time Distribution ◽  
Response Times ◽  
Response Time Distribution ◽  
Stroop Interference ◽  
Response Conflict ◽  
Distribution Analysis ◽  
Manual Response ◽  
Response Interference

Abstract. Previous analyses of response time distributions have shown that the Stroop effect is observed in the mode (μ) and standard deviation (σ) of the normal part of the distribution, as well as its tail (τ). Specifically, interference related to semantic and response processes has been suggested to specifically affect the mode and tail, respectively. However, only one study in the literature has directly manipulated semantic interference, and none manipulating response interference. The present research aims to address this gap by manipulating both semantic and response interference in a manual response Stroop task, and examining how these components of Stroop interference affect the response time distribution. Ex-Gaussian analysis showed both semantic and response conflict to only affect τ. Analyzing the distribution by rank-ordered response times (Vincentizing) showed converging results as the magnitude of both semantic and response conflict increased with slower response times. Additionally, response conflict appeared earlier on the distribution compared to semantic conflict. These findings further highlight the difficulty in attributing specific psychological processes to different parameters (i.e., μ, σ, and τ). The effect of different response modalities on the makeup of Stroop interference is also discussed.

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