Effects on the glaciers

Storyboard

>Model

ID:(582, 0)



Glaciers

Description

ID:(95, 0)



effect015

Description

![effect015](showImage.php)
effect015

ID:(7410, 0)



effect010

Description

![effect010](showImage.php)
effect010

ID:(7405, 0)



effect012

Description

![effect012](showImage.php)
effect012

ID:(7407, 0)



effect014

Description

![effect014](showImage.php)
effect014

ID:(7409, 0)



effect011

Description

![effect011](showImage.php)
effect011

ID:(7406, 0)



effect013

Description

![effect013](showImage.php)
effect013

ID:(7408, 0)



effect037

Description

![effect037](showImage.php)
effect037

ID:(7430, 0)



effect009

Description

![effect009](showImage.php)
effect009

ID:(7404, 0)



effect032

Description

![effect032](showImage.php)
effect032

ID:(7425, 0)



effect016

Description

![effect016](showImage.php)
effect016

ID:(7411, 0)



Effects on the glaciers

Description

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

(ID 95)

![effect015](showImage.php)
effect015

(ID 7410)

![effect010](showImage.php)
effect010

(ID 7405)

![effect012](showImage.php)
effect012

(ID 7407)

![effect014](showImage.php)
effect014

(ID 7409)

![effect011](showImage.php)
effect011

(ID 7406)

![effect013](showImage.php)
effect013

(ID 7408)

![effect037](showImage.php)
effect037

(ID 7430)

![effect009](showImage.php)
effect009

(ID 7404)

![effect032](showImage.php)
effect032

(ID 7425)

![effect016](showImage.php)
effect016

(ID 7411)

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

$ v_a =\displaystyle\frac{(1 - a_{ev} )(1 - \gamma_v ) I_s - ( \lambda / h ) \Delta T_b }{ \rho_e (l + c \Delta T_m )}$

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

(ID 7432)

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:

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

(ID 7612)

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

$ v_b = v_c - v_a$

turns out to be negative.

(ID 7434)

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

$ v_b = v_c - v_a$



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

$\Delta h=v_b\Delta t$

(ID 8249)


ID:(582, 0)