Re: ice melting

On 16 Dec 2008 21:27:56 GMT, William Asher wrote:

George <george@xxxxxxxxxxxxxxx> wrote in

WASHINGTON (AP) - More than 2 trillion tons of land ice in Greenland,
Antarctica and Alaska have melted since 2003, according to new NASA
satellite data that show the latest signs of what scientists say is
global warming.

More than half of the loss of landlocked ice in the past five years
has occurred in Greenland, based on measurements of ice weight by
NASA's GRACE satellite, said NASA geophysicist Scott Luthcke. The
water melting from Greenland in the past five years would fill up
about 11 Chesapeake Bays, he said, and the Greenland melt seems to be
accelerating.

! end excerpt

You're off by a factor of 1000 somewhere, I don't know where. The actual
sea level rise from that much ice is 4 mm. It was in a news release.

Yeah, it's in your volume conversion, 0.01*cm = m, not 0.001*cm = m.

Thanks, Bill.

That actually tilts it the other way. You could make an argument that
missing by three orders of magnitude is complete failure, as it motivates
the wrong choice for policy makers, which would be to claim the evidence
absurd and not take stock of the rising seas.

I think I've got it here, though, and I think it's a quarter cm or so:

implicit none

INTEGER,PARAMETER::dp=SELECTED_REAL_KIND(15)

real(kind=dp) :: r1,r2,v1,v2,tonnage1,density, proportion
real(kind=dp) :: kilometer_cube_of_water, metric_grams
real(kind=dp) :: sphere_factor, pi, test, diff, delta_km, target
real(kind=dp) :: zax, fractional_cm, fuuq, comparison_value

! kilometer_cube_of_water


! 0.998 g/cm³ (liquid at 20 °C, 1 atm)
density = .998_dp

! one cubed kilometer is 10**15 cm

kilometer_cube_of_water = 10.0_dp**15 * density

print *, "a cubic kilometer of water at 20 degrees"
print *, "and one atmosphere weighs: ", kilometer_cube_of_water&
, "grams"


! incremental_centimeter


r1 = 6371.0_dp ! earth radius in km



pi = 4.0_dp * atan(1.0_dp)
print *, pi


sphere_factor = (4.0_dp/3.0_dp) * pi
print *, "scalar factor is ", sphere_factor

!test: Volume of earth is 1.0832073×1012 km³

test = sphere_factor * r1**3

print *, test
print *, '1.0832073'
print *, "agreement to six decimal places"

! there are 10^5 cm's in a kilometer
r1 = r1 * 10.0**5
print *, "radius in cm of earth is ", r1

r2 = r1 + 1.0_dp

v1 = sphere_factor * r1**3
v2 = sphere_factor * r2**3

diff = v2-v1
print *, "difference in cubic centimeters is", diff
print *, " that's a whopper ^^^^"

delta_km = diff / 10.0**15
print *, "difference in cubic kms is", delta_km

tonnage1 = 2000000000000.0_dp ! 2 trillion tons of land ice
metric_grams = 907184.74_dp ! one ton = this many grams
target = tonnage1 * metric_grams

print *, "target: ", target, "grams is the mass lost as per nasa satellite"

! see how this compares with a centimeter of water over the entire world

zax = kilometer_cube_of_water * delta_km
print *, "a centimeter of water over the whole earth" &
, " weighs: ", zax, " grams"

print *, "but it's not the whole earth"
proportion = .708_dp ! 71 % water
fuuq = zax / proportion
print *, "fuuq ", fuuq

comparison_value = 1.0e19
print *, "comparison_value: ", comparison_value


fractional_cm = fuuq/target
print *, "sea rise is ", fractional_cm, " in fractional cm's"


endprogram
! g95 -Wall ice3.f03 -o k.exe


C:\MinGW\source>g95 -Wall ice3.f03 -o k.exe

C:\MinGW\source>k
a cubic kilometer of water at 20 degrees
and one atmosphere weighs: 9.98E+14 grams
3.141592653589793
scalar factor is 4.1887902047863905
1.0832069168457535E+12
1.0832073
agreement to six decimal places
radius in cm of earth is 6.371E+8
difference in cubic centimeters is 5.100644749174374E+18
that's a whopper ^^^^
difference in cubic kms is 5100.644815528132
target: 1.81436948E+18 grams is the mass lost as per nasa satellite
a centimeter of water over the whole earth weighs: 5.090443525897076E+18
gram
s
but it's not the whole earth
fuuq 7.189891985730334E+18
comparison_value: 9.999999980506448E+18
sea rise is 3.9627496300975773 in fractional cm's

C:\MinGW\source>

Where it's going off the rails for me here is with scientic notation and
fortran. How do I compare 7.18 e18 to 1.81 e18 without doing someting
stupid? I found nothing in the index of MR&C and Adams.

Is there an intrinsic that raises a real to a real?
--
George

I am mindful not only of preserving executive powers for myself, but for
predecessors as well.
George W. Bush

Picture of the Day http://apod.nasa.gov/apod/
.

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