Effects on the glaciers

Storyboard

>Model

ID:(582, 0)



Glaciers

Definition

ID:(95, 0)



effect015

Image

![effect015](showImage.php)

effect015

ID:(7410, 0)



effect010

Note

![effect010](showImage.php)

effect010

ID:(7405, 0)



effect012

Quote

![effect012](showImage.php)

effect012

ID:(7407, 0)



effect014

Exercise

![effect014](showImage.php)

effect014

ID:(7409, 0)



effect011

Equation

![effect011](showImage.php)

effect011

ID:(7406, 0)



effect013

Script

![effect013](showImage.php)

effect013

ID:(7408, 0)



effect037

Variable

![effect037](showImage.php)

effect037

ID:(7430, 0)



effect009

Audio

![effect009](showImage.php)

effect009

ID:(7404, 0)



effect032

Video

![effect032](showImage.php)

effect032

ID:(7425, 0)



effect016

Unit

![effect016](showImage.php)

effect016

ID:(7411, 0)



Effects on the glaciers

Storyboard

Variables

Symbol
Text
Variable
Value
Units
Calculate
MKS Value
MKS Units
$a_{ev}$
a_ev
Albedo del Hielo
-
$h_e$
h_e
Altura capa de hielo
m
$\Delta x$
Dx
Altura deshielo
m
$l_e$
l_e
Calor Latente del Hielo
J/mol
$c_e$
c_e
Capacidad calorica del Hielo
J/kg K
$\gamma_v$
gamma_v
Cobertura Zona Glaciar
-
$\lambda$
lambda
Conductividad termica del Hielo
W/m K
$\rho_e$
rho_e
Densidad del Hielo
kg/m^3
$\Delta T_b$
dT_b
Diferencia Temperatura Glaciar Superficie-Base
K
$\Delta T_e$
dT_e
Diferencia Temperatura para deretir Superficie
K
$I_s$
I_s
Intensidad del Sol
W/m^2
$\Delta t$
Dt
Tiempo deshielo
s
$\Delta t$
Dt
Time elapsed
s
$\Delta h$
Dh
Variación de Altura de Glaciar
m
$v_a$
v_a
Velocidad de Deshielos
m/s
$v_c$
v_c
Velocidad de Nevación
m/s
$v_b$
v_b
Velocidad Efectiva de Deshielo
m/s

Calculations


First, select the equation:   to ,  then, select the variable:   to 

Symbol
Equation
Solved
Translated

Calculations

Symbol
Equation
Solved
Translated

 Variable   Given   Calculate   Target :   Equation   To be used



Equations


Examples

![effect015](showImage.php)

effect015

![effect010](showImage.php)

effect010

![effect012](showImage.php)

effect012

![effect014](showImage.php)

effect014

![effect011](showImage.php)

effect011

![effect013](showImage.php)

effect013

![effect037](showImage.php)

effect037

![effect009](showImage.php)

effect009

![effect032](showImage.php)

effect032

![effect016](showImage.php)

effect016

To calculate the ablation rate (melting speed), we\'ll assume that the glacier has a height h and is at a temperature $\Delta T$ below the melting point. The energy captured by a layer of height $\Delta x$ is partly conducted into the glacier, contributing to the melting of the layer and its warming. If l is the latent heat and $\rho_e$ the ice density, a volume element with surface $S$ and height $\Delta x$ will require the energy

$\Delta Ql = S\Delta x l \rho_e$



to melt.

To heat it up to the melting temperature $\Delta T_m$, it will require

$\Delta Q_c = S\Delta x\rho_ec\Delta T_m$



where c is the specific heat. Lastly, thermal conduction will remove heat

$\Delta Q_{\lambda}=\displaystyle\frac{\lambda S\Delta T_b}{h}\Delta t$



where $\lambda$ is the thermal conductivity, $\Delta T_b$ is the base-surface temperature difference, and $\Delta t$ is the elapsed time.

Therefore, the total heat will be

$\Delta Q_l + \Delta Q_c + \Delta Q_{\lambda} = (1 - a_{ev})(1 - \gamma_v)S I_s\Delta t$



which, after replacing with the expressions, becomes

$S\Delta xl\rho_e + S\Delta x\rho_ec\Delta T_m + (\lambda/h)S \Delta T_b \Delta t = (1 - a_{ev})(1 - \gamma_v)S I_s\Delta t$



Solving for \Delta x, we get the expression for the melting speed

kyon

Hence, an increase in temperature leads to an increase in the ablation rate.

The accumulation rate, denoted as v_c, is calculated from the amount of snow, \Delta x, that falls within a time interval, \Delta t, as per the formula:

kyon

Solar radiation is partly reflected and partly absorbed by the surface. If $I_s$ is the radiation flux, $a_{ev}$ is the Earth\'s visible albedo, and $\gamma_v$ is the coverage factor, the absorbed fraction is

$(1 - a_{ev})(1 -\gamma_v)I_s$



The heat supplied is partly conducted into the glacier\'s interior and partly contributes to melting a layer of thickness $\Delta x$ in a time $\Delta t$.

In this way, the glacier\'s surface would decrease at an ablation rate (melting speed)

$v_a =\displaystyle\frac{\Delta x}{\Delta t}$



due to the melting effect, while it would grow at an accumulation rate $v_c$ (snow deposition speed) due to the effect of snow being deposited on its surface. Therefore, melting would occur if the total velocity

kyon

turns out to be negative.

La taza de balance de masa que se calcula de la taza de acumulaci n y la taza de ablaci n

equation=7434

permite estimar la variaci n en la altura especifica del glaciar (en un lugar en particular)

equation


>Model

ID:(582, 0)