Welcome to the PDS Atmospheres Node
Standard Planetary Information, Formulae and Constants
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TABLE OF CONTENTS
Summary of constantsTables of atmospheric parameters for the planets
Adiabatic Lapse Rate
Auto-convective Lapse Rate
Amagats
Beers Law
Beta plane approximation
Brunt Vaisala or Buoyancy Frequency
Cloud clearing eta and N* methods
Cloud properties
Dobson Units
Double Linear Interpolation
Earth: molecular abundances
Earth: Molecular spectral regions
Earth: Oceans
Equations of Motion
FFT, Cosine Transform
Gas Constant
Geopotential
Geostrophic Approximation
Gravity
Heat Balance
Humidity
Hurricanes
Hydrostatic Equilibrium
Ideal Gas Law
IR filter bandpasses
Latitude: planeto-graphic and planeto-centric
Longitude Systems and Conversion
Orbits: Equations of motion, Period(altitude)
Planck Function
Planet Mission Summary
Potential Temperature
Potential Vorticity
Radiative time constant
Radiative Transfer Equation (IR)
Rayleigh Scattering: Optical Depth
Rayleigh Scattering: Phase Function
Richardson Number
Rossby Number
Saturation Vapor Pressure
Scale Height
Thermal Wind Equation
Velocity of Sound
Vorticity
Weighting Functions
Wind Measurement
Physical Constants
(ref. Physics Today, Aug. 1995 pg. BG9)
AU = astronomical unit = 1.4960 · 1013 cm
c = speed of light = 2.99792458 · 1010 cm/s
G = 6.67259(85) · 10-8 dyne cm2/gm2
h = Planck's constant = 6.626075(40) · 10-27 erg sec
k = Boltzmann's constant = 1.380658(12) · 10-16 erg/K
Na = Avogadro's number = 6.0221367(36) · 1023 gm/mole
= Stefan-Boltzmann constant = 5.67051(19) · 10-5
erg/s/cm2/K4
S0 = 1.37 · 106 erg/cm2
Runiv = Na · k = 8.3143 · 107 erg/mole/K
<mw>H2O = 18.016 gm/mole
<mw>O3 = 47.9982 gm/mole
Earth Constants
Req = 6378.388 km
M = 5.975 · 1027 gm
<mw>dry air = 28.964 gm/mole
Rg = 0.28705 · 107 erg/gm/K
N0 = Loschmidt's number = 2.686763(23) · 1019 molecules/cm3
gs = Standard surface gravity = 980.665 cm/s
Ps = Standard surface pressure = 1.01325 · 106 dyne/cm2
cp = 1.006 · 107 erg/gm/K at stp
cv = 0.718 · 107 erg/gm/K at stp
= cp/cv = 1.401 at stp
Unit Conversion
1 knot = 1 nautical mile/hour = 1.151555 mile/hour = 1.853248 Km/hr
1 megaton = 4.2 · 1022 erg = 4.2 · 1015 Joule
1 AU = 1.495 · 108 Km = 8.31 light minutes
Tables of atmospheric parameters for the planets
area Km2 | volume Km3 | Mass grams | Mass M | density gm/cm3 | |
Venus | 4.6011e+08 | 9.2805e+11 | 4.8850e+27 | 0.817 | 5.264 |
Earth | 5.1006e+08 | 1.0832e+12 | 5.9790e+27 | 1.000 | 5.520 |
Mars | 1.4416e+08 | 1.6275e+11 | 6.4570e+26 | 0.108 | 3.967 |
Jupiter | 6.1469e+10 | 1.4313e+15 | 1.8986e+30 | 317.551 | 1.327 |
Saturn | 4.2694e+10 | 8.2713e+14 | 5.6854e+29 | 95.089 | 0.687 |
Uranus | 8.0840e+09 | 6.8336e+13 | 8.6825e+28 | 14.522 | 1.271 |
Neptune | 7.6280e+09 | 6.2637e+13 | 1.0310e+29 | 17.244 | 1.646 |
Titan | 8.3323e+07 | 7.1519e+10 | 1.3500e+26 | 0.023 | 1.888 |
hours | hr:mn:secs | day/earth | °/day | |
Venus | -5833.2000000 | -5833:12: 0.0 | -243.05000 | 1.481177 |
Earth | 23.9333330 | 23:56: 0.0 | 0.99722 | 361.002791 |
Mars | 24.6333330 | 24:38: 0.0 | 1.02639 | 350.744254 |
Jupiter: SI.. | 9.8416675 | 9:50:30.0 | 0.41007 | 877.900010 |
Jupiter: SII. | 9.9279533 | 9:55:40.6 | 0.41366 | 870.270008 |
Jupiter: SIII | 9.9249197 | 9:55:29.7 | 0.41354 | 870.536010 |
Saturn: SI.. | 10.2333290 | 10:14: 0.0 | 0.42639 | 844.300032 |
Saturn: SIII | 10.6562220 | 10:39:22.4 | 0.44401 | 810.793919 |
Uranus | -17.2333330 | -17:14: 0.0 | -0.71806 | 501.353975 |
Neptune | 16.1100000 | 16: 6:36.0 | 0.67125 | 536.312849 |
Titan | 382.6799927 | 382:40:48.0 | 15.94500 | 22.577611 |
a(AU) | period(yrs) | inclin(°) | a.node(°) | arg.perih(°) | ecc | L(6430)(°) | |
Venus | 0.7233 | 0.62 | 3.39 | 76.55 | 131.25 | 0.006818 | 267.689 |
Earth | 1.0000 | 1.00 | 0.00 | 0.00 | 102.77 | 0.016704 | 99.372 |
Mars | 1.5237 | 1.88 | 1.85 | 49.45 | 335.82 | 0.093329 | 195.082 |
Jupiter | 5.2025 | 11.87 | 1.31 | 100.35 | 15.46 | 0.048075 | 329.233 |
Saturn | 9.5531 | 29.53 | 2.49 | 113.55 | 92.20 | 0.051565 | 238.772 |
Uranus | 19.2642 | 84.55 | 0.77 | 73.99 | 175.28 | 0.046227 | 253.217 |
Neptune | 30.2337 | 166.24 | 1.77 | 131.82 | 7.60 | 0.007972 | 274.526 |
Titan | 0.0082 | 0.04 | 0.33 | 0.00 | 0.00 | 0.030000 | 0.000 |
<r>(AU) | inclin(°) | RA(°) | DEC(°) | |
Venus | 0.7233 | 177.40 | 272.78 | 67.21 |
Earth | 1.0000 | 23.40 | 0.00 | 90.00 |
Mars | 1.5237 | 25.20 | 317.57 | 57.52 |
Jupiter | 5.2025 | 3.10 | 268.04 | 64.49 |
Saturn | 9.5531 | 26.70 | 39.36 | 83.45 |
Uranus | 19.2642 | 97.90 | 257.43 | -15.10 |
Neptune | 30.2337 | 29.00 | 295.33 | 40.65 |
Titan | 0.0082 | 0.00 | 0.00 | 0.00 |
Vorbit Km/s | Vescape Km/s | Vequator Km/s | Vsound Km/s | |
Venus | 35.022 | 10.378 | -0.002 | 0.236 |
Earth | 29.786 | 11.192 | 0.465 | 0.320 |
Mars | 24.130 | 5.045 | 0.240 | 0.227 |
Jupiter | 13.059 | 60.511 | 12.572 | 0.816 |
Saturn | 9.637 | 36.376 | 9.871 | 0.716 |
Uranus | 6.786 | 21.411 | -2.589 | 0.543 |
Neptune | 5.417 | 23.670 | 2.689 | 0.543 |
Titan | 5.573 | 2.645 | 0.012 | 0.185 |
Teff K | Peff mBar | gm/cm3 | H Km | Vsound m/s | rad years | phase ° | |
Venus | 229.0 | 20.000 | 4.6230e-05 | 4.862 | 235.8 | 0.007 | 3.94 |
Earth | 255.0 | 500.000 | 6.8297e-04 | 7.471 | 320.2 | 0.131 | 39.47 |
Mars | 210.0 | 6.000 | 1.5124e-05 | 10.605 | 226.6 | 0.006 | 1.17 |
Jupiter | 124.0 | 400.000 | 8.6132e-05 | 19.146 | 816.3 | 4.534 | 67.39 |
Saturn | 95.0 | 300.000 | 8.1128e-05 | 36.975 | 715.5 | 20.794 | 77.27 |
Uranus | 59.0 | 430.000 | 2.0161e-04 | 24.234 | 543.4 | 131.311 | 84.15 |
Neptune | 59.0 | 500.000 | 2.3443e-04 | 19.206 | 543.4 | 121.008 | 77.67 |
Titan | 85.0 | 1.000 | 4.0568e-06 | 18.152 | 184.7 | 0.053 | 82.54 |
T K | P mBar | gm/cm3 | H Km | Vsound m/s | rad years | phase ° | |
Venus | 400.0 | 50.000 | 6.6166e-05 | 8.492 | 311.7 | 0.003 | 1.85 |
Earth | 270.0 | 1.000 | 1.2901e-06 | 7.911 | 329.5 | 0.000 | 0.08 |
Mars | 140.0 | 0.005 | 1.8905e-08 | 7.070 | 185.0 | 0.000 | 0.00 |
Jupiter | 163.0 | 3.000 | 4.9143e-07 | 25.167 | 935.9 | 0.015 | 0.45 |
Saturn | 145.0 | 2.000 | 3.5435e-07 | 56.435 | 884.0 | 0.039 | 0.48 |
Uranus | 120.0 | 1.000 | 2.3053e-07 | 49.290 | 775.0 | 0.036 | 0.15 |
Neptune | 130.0 | 2.000 | 4.2559e-07 | 42.319 | 806.7 | 0.045 | 0.10 |
Titan | 170.0 | 1.000 | 2.0284e-06 | 36.304 | 261.3 | 0.007 | 43.69 |
T K | P mBar | gm/cm3 | H Km | Vsound m/s | rad years | phase ° | |
Venus | 250.0 | 100.000 | 2.1173e-04 | 5.307 | 246.4 | 0.026 | 14.83 |
Earth | 217.0 | 100.000 | 1.6051e-04 | 6.358 | 295.4 | 0.043 | 14.96 |
Mars | 140.0 | 0.010 | 3.7809e-08 | 7.070 | 185.0 | 0.000 | 0.01 |
Jupiter | 110.0 | 140.000 | 3.3983e-05 | 16.984 | 768.8 | 2.273 | 50.28 |
Saturn | 85.0 | 100.000 | 3.0224e-05 | 33.083 | 676.8 | 9.677 | 64.10 |
Uranus | 53.0 | 110.000 | 5.7414e-05 | 21.770 | 515.1 | 46.340 | 73.81 |
Neptune | 54.0 | 200.000 | 1.0246e-04 | 17.579 | 519.9 | 63.132 | 67.26 |
Titan | 70.0 | 100.000 | 4.9261e-04 | 14.949 | 167.7 | 9.506 | 89.96 |
T K | P BAR | gm/cm3 | H Km | Vsound m/s | rad years | phase ° | |
Venus | 360.0 | 1.000 | 1.4704e-03 | 7.643 | 295.7 | 0.087 | 41.57 |
Earth | 288.0 | 1.000 | 1.2094e-03 | 8.438 | 340.3 | 0.182 | 48.82 |
Mars | 140.0 | 0.007 | 2.6466e-05 | 7.070 | 185.0 | 0.024 | 4.59 |
Jupiter | 165.0 | 1.000 | 1.6182e-04 | 25.476 | 941.6 | 4.811 | 68.57 |
Saturn | 134.0 | 1.000 | 1.9172e-04 | 52.154 | 849.8 | 24.699 | 79.23 |
Uranus | 76.0 | 1.000 | 3.6399e-04 | 31.217 | 616.8 | 142.873 | 84.62 |
Neptune | 76.0 | 1.000 | 3.6399e-04 | 24.740 | 616.8 | 113.230 | 76.85 |
Titan | 86.0 | 1.000 | 4.0096e-03 | 18.66 | 185.8 | 51.265 | 89.99 |
T K | P BAR | gm/cm3 | H Km | Vsound m/s | rad years | phase ° | |
Venus | 731.0 | 92.000 | 6.6619e-02 | 15.519 | 421.4 | 0.954 | 84.14 |
Earth | 288.0 | 1.013 | 1.2252e-03 | 8.438 | 340.3 | 0.184 | 49.19 |
Mars | 214.0 | 0.007 | 1.7314e-05 | 10.807 | 228.7 | 0.007 | 1.29 |
Jupiter | 294.0 | 7.000 | 6.3574e-04 | 45.394 | 1256.9 | 5.953 | 72.40 |
Saturn | 313.0 | 21.000 | 1.7237e-03 | 121.823 | 1298.8 | 40.698 | 83.41 |
Uranus | 366.0 | 260.000 | 1.9651e-02 | 150.336 | 1353.5 | 332.598 | 87.68 |
Neptune | 360.0 | 283.000 | 2.1746e-02 | 117.192 | 1342.3 | 301.495 | 84.98 |
Titan | 94.0 | 1.500 | 5.5026e-03 | 20.074 | 194.3 | 58.887 | 89.99 |
Adiabatic Lapse Rate, Dry
from the first law of thermodynamics
where cv is given in units of erg/K/mole and n is the number of moles. The derivative of the ideal gas law, P · V = n R T, is
equating P dV and noting that R = cp - cv yields
Cp = cp/<mw> and = n · <mw>/V so that
From hydrostatic equilibrium and the gas law we can convert from pressure to height coordinates:
<g> cm/s2 | Cp J/gm/K | Adiabatic Lapse Rate K/Km | Rg J/gm/K | Autoconvective Lapse Rate K/Km | |
Venus | 889.89 | 0.8501 | 10.468 | 0.18892 | 47.104 |
Earth | 979.86 | 1.0040 | 9.760 | 0.28710 | 34.130 |
Mars | 374.10 | 0.8312 | 4.500 | 0.18892 | 19.802 |
Jupiter | 2425.61 | 12.3591 | 1.963 | 3.74518 | 6.477 |
Saturn | 1000.09 | 14.0129 | 0.714 | 3.89246 | 2.569 |
Uranus | 880.07 | 13.0137 | 0.676 | 3.61491 | 2.435 |
Neptune | 1110.46 | 13.0137 | 0.853 | 3.61491 | 3.072 |
Titan | 135.80 | 1.0440 | 1.301 | 0.29000 | 4.683 |
Autoconvective Lapse Rate
From hydrostatic equilibrium and the ideal gas law,
P = Rg (z) T(z) we have
But T(z) and (z) are always positive so that when
then d/dz 0. Thus, the autoconvective criteria is that when the density increases with altitude the atmosphere will be forced to convectively adjust and this condition is met when
Amagats
From the ideal gas law we can define the number of particles at standard temperature (273.15 K) and standard pressure (1 atm = 1013.25 milli-bars). The ideal gas law can be written many ways, here we will adopt the notation(s)where, N is the number of molecules per unit volume, Boltzmann's constant k = 1.3806 · 10-16 erg/K, the gas constant
Rg = Na · k/<mw>, Avogadro's number, Na = 6.02 · 1023 particles per mole, <mw> is the molecular weight in grams/mole.
This number of molecules at STP is called Loschmidt's number and has the value,
The number of amagats of a gas is given as a ratio of the actual number of particles at the given temperature and pressure to Loschmidt's number. In planetary atmospheres the number density is a function of height. We can calculate the thickness of an equivalent atmospheric column at standard temperature and pressure. This is denoted as cm-amagats or Km-amagats and is given by
Hydrostatic equilibrium relates the pressure and vertical coordinates
and the number density, Ni can be written as a function of the density,
where, qi is the volumetric fraction of species i.
Earth | Mars | Jupiter | Saturn | Titan | Uranus | Neptune | |
g | 981.0 | 374.1 | 2425.3 | 1000.0 | 136.0 | 880.1 | 1110.5 cm/s |
q(H2) | 1.00 | 1.00 | 0.90 | 0.96 | 1.00 | 0.85 | 0.85 |
<mw> | 28.97 | 44.01 | 2.22 | 2.14 | 28.00 | 2.30 | 2.30 gm/mole |
H0 | 7.88 | 13.61 | 37.45 | 100.50 | 58.85 | 94.08 | 74.56 Km-am/Bar |
1000/H0 | 126.9 | 73.49 | 26.70 | 9.95 | 16.99 | 10.63 | 13.41 mB/Km-am |
Beer's Law
Transmittance between the top of the atmosphere and level at z is a function of the quantity and absorption of all gases.
Beta Plane Approximation
rad/s | f(45) s-1 | f(60) s-1 | f/fearth | 0 (cm*s)-1 | |
Venus | -2.9921e-07 | -4.2314e-07 | -4.2314e-07 | -0.004103 | -9.889e-16 |
Earth | 7.2925e-05 | 1.0313e-04 | 1.0313e-04 | 1.000000 | 2.287e-13 |
Mars | 7.0852e-05 | 1.0020e-04 | 1.0020e-04 | 0.971583 | 4.176e-13 |
Jupiter | 1.7585e-04 | 2.4869e-04 | 2.4869e-04 | 2.411438 | 4.920e-14 |
Saturn | 1.6378e-04 | 2.3163e-04 | 2.3163e-04 | 2.245949 | 5.435e-14 |
Uranus | -1.0128e-04 | -1.4323e-04 | -1.4323e-04 | -1.388781 | -7.925e-14 |
Neptune | 1.0834e-04 | 1.5321e-04 | 1.5321e-04 | 1.485620 | 8.730e-14 |
Titan | 4.5608e-06 | 6.4500e-06 | 6.4500e-06 | 0.062541 | 3.542e-14 |
Brunt Vaisala or Buoyancy Frequency
where, T0(z) = <T(z,,,t)>, i.e., temperature averaged over longitude , latitude , and time t.
The static stability, , is related to the buoyancy frequency as
The static stability is positive for stable conditions and zero or negative for unstable conditions.
Cloud clearing, method
Given the clear radiance, Rclr and the fraction of clouds,
i in scene i.
Chahine, M.T. 1974, J. Atmos. Sci. 31 p.233
Susskind, J., J. Joiner and C.D. Barnet 1995. Determination of
atmospheric and surface parameters from simulated AIRS/AMSU sounding
data. I. Retrieval methodology. submitted to J. Atmos. Oceanic
Tech. (JAOT) Sep. 1995.
Cloud clearing, N* method
McMillin, L.M. and C. Dean 1982. Evaluation of a new operational technique for producing clear radiances. J. Appl. Meteor. 21 p.1005-1014.
Smith, W.L. 1968. An improved method for calculating tropospheric
temperature and moisture from satellite radiometer measurements.
Monthly Weather Review 96 p.387-396.
Clouds, Properties
from NOAA chart
low clouds:
middle clouds:
high clouds:
Reff | Veff (Hansen, 1971) | |
Fair Weather cumulus | 5.56 | 0.111 |
Altostratus | 7.01 | 0.113 |
Stratus | 11.19 | 0.193 |
Cumulus congestus | 10.48 | 0.147 |
Stratocumulus | 5.33 | 0.118 |
Nimbostratus | 10.81 | 0.143 |
Earth is typically covered about 50%
average precipitable water is about 2.5 cm
average time aloft is 9 days (from 100 cm of rain/year)
in thunderstorm approximately 10% of water is released
suspended droplets 1 µm to 100 µm
cloud over continents have smaller droplets
Dobson Units
given the number density, N, in molecules per cm3 then
Note that = q · t = N · <mw> /Na where q is the volumetric mixing ratio of the species being measured.
To convert to mass column density, M, in grams per cm2
where N0 is Loschmidt's number.
The atmosphere consists of fixed gases (e.g., CO2,
N2O, CO), water, and ozone so the pressure within any level
is given as
so that
we can also define the total column density as
and if we require
then,
Ct(L) in eqn 6 and <mw> can be solved for iteratively with an initial guess of <mw> = <mw>f
The volumetric mixing ratio, i.e., molecules of species x to the total number of molecules, is given by
Double Linear Interpolation
x = s - s0, 0 x 1
y = l - l0, 0 y 1
s1 = s0 + 1, l1 = l0 + 1
DN(s,l0) = DN(s0,l0) + x · (DN(s1,l0)-DN(s0,l0))
DN(s,l1) = DN(s0,l1) + x · (DN(s1,l1)-DN(s0,l1))
DN(s,l) = DN(s,l0) + y · (DN(s,l1) - DN(s,l0))
or
DN(s,l) = DN(s0,l0)
Earth: molecular abundances
From US Standard Atmosphere 1976, Table 3 and
page 33 (Trace Constituents)
Gas | <mw> gm/mole |
H | 1.00794 |
C | 12.011 |
N | 14.00674 |
O | 15.9994 |
S | 32.066 |
Gas | <mw> gm/mole | volumetric fi |
N2 | 28.0134 | 0.78084 |
O2 | 31.9988 | 0.209476 |
Ar | 39.948 | 0.00934 |
CO2 | 44.00995 | 314 ppmv |
Ne | 20.183 | 18.18 ppmv |
He | 4.0026 | 5.24 ppmv |
Kr | 83.80 | 1.14 ppmv |
Xe | 131.30 | 0.087 ppmv |
CH4 | 16.04303 | 1.5 ppmv |
H2 | 2.01594 | 0.5 ppmv |
<<mw>> | 28.9644 | |
H2O | 18.016 | f 0.005 at 1 km (900 mB) |
O3 | 47.9982 | f 20 ppmv at 36 km (5 mB) |
N2O | 44.0129 | 270 ppbv |
NO | 30.0061 | 0.5 ppbv |
NO2 | 46.0055 | 1 ppbv |
H2S | 34.0819 | 0.05 ppbv |
NH3 | 17.0306 | 4 ppbv |
SO2 | 64.0648 | 1 ppbv |
CO | 28.0104 | 190 ppbv |
Methane, CH4
1992 1.7086 ppm
1984 1.6180 ppm --> +0.0113 ppm/year = +0.7 %/year
0.02 ppm peak-to-peak seasonal variation = ± 0.01 ppm = ± 0.62 %
qCH4 = 1.618 + 0.0113 · (t-1984.0) ± 0.01 ppm
Carbon Dioxide, CO2
1995 361.0 ppm
1980 336.8 ppm --> +1.6 ppm/year = +0.475 %/year
0.105 ppm peak-to-peak seasonal variation = ± 0.052 ppm = ± 0.015 %
qCO2 = 337 + 1.6 · (t-1980.0) ± 0.052 ppm
C12O16O18 = 4.08 · 10-3
· C12O16O16
C12O16O17 = 7.42 · 10-4
· C12O16O16
Kiehl & Ramanathan 1983. JGR 88 p.5191.
C13O16O16 = 1.12 · 10-2
· C12O16O16
Earth: molecular spectral regions
CO2 15 µm spectral region
2 (667.381 bending mode) vibrational-rotational band
1 (1388.23 symmetric stretch mode) fermi-resonance
stimulated by 2 (618.029, 720.805)
B(CO2) = 0.39 cm-1
Q-branch at 667.5 (2 mb)
line wings have 1.5 scale height wide weighting functions
line centers have 2.5 scale height weighting functions
band cm-1 | S at 180 K cm-2 amagat | A0 cm-1 | 0 atm-1 cm-1 | d cm-1 |
667 | 549 | 17.3 | 0.097(300/T)(2/3) | 1.56 |
2350 | 4505 | 15.4 | 0.097(300/T)(2/3) | ?? |
3715 | 102 | 32.2 | 0.097(300/T)(2/3) | ?? |
band cm-1 | transition 123 | S at 300 K cm-2 amagat | Ej cm-1 | d cm-1 |
667.381 | 0000 --> 0110 | 194 | 0.0 | 1.56 |
667.751 | 0110 --> 0220 | 15 | 667.381 | 0.78 |
720.805 | (I) 0110 --> 1000 | 5.00 | 667.381 | 1.56 |
618.029 | (II) 0110 --> 1000 | 4.27 | 667.381 | 1.56 |
668.107 | 0220 --> 0330 | 0.85 | 1335.131 | 0.78 |
647.063 | (II) 1000 --> 1110 | 0.7 | 1285.410 | 1.56 |
668.670 | (I) 1000 --> 1110 | 0.3 | 1388.185 | 1.56 |
NOTE: for C12O16O17 and C12O16O18 the mean line spacing is 0.78 for all bands
CO2 4.3 µm spectral region
3 (2349.16 asymmetric stretch mode) band, no Q-branch
high T dependence of high J lines makes narrower weighting functions free of
isotopes and hot lines
H2O 6.3 µm spectral region}
band | H2O | HDO |
1 | 3657.05 | 2723.68 |
2 | 1594.75 | 1403.49 |
3 | 3755.93 | 3707.47 |
non-linear molecule with angle of 104.45° 1 ~ 3 ~ 2 · 2
O3 9.6 µm spectral region
1 1110 cm-1
2 1045 cm-1
3 701 cm-1
CH4 spectrum
of the 9 modes, only 1 through 4 are independent, and
3 and 4 are triply degenerate.
13C is 1.108 % of all Carbon
band | 12CH4 | 13CH4 |
4 | 1310.76 | 1302.77 |
2 | 1533.37 | |
3 | 3018.92 | 3009.53 |
24 | 2612 | |
2 + 4 | 2830 | 2822 |
22 + 4 | 3062 | |
1 + 4 | 4223 | |
3 + 4 | 4340 | |
2 + 3 | 4540 |
band cm-1 | S cm-2 amagat-1 | A0 cm-1 | 0 atm-1 cm-1 | d cm-1 |
1306 | 185 | 52(T/300)0.5 | 0.075(300/T)0.5 | 5.3 |
3020 | 320 | 124(T/300)0.5 | 0.075(300/T)0.5 | 10.5 |
4220 | 20 | 124(T/300)0.5 | 0.075(300/T)0.5 | 10.5 |
5861 | 3 | 124(T/300)0.5 | 0.075(300/T)0.5 | 10.5 |
Earth: Oceans
P(Bar) = 981 cm/s2 * 12*2.54 * Z(ft) * (gm/cm3) * 1.0E-6 Bar/(dyn/cm2)
P(Bar) = 31.0 * Z(1000 ft)
Z(ft) | (gm/cm3) |
0 | 1.028 (assume 35 parts-per-thousand salinity) |
1000 | 1.033 |
2000 | 1.0375 |
20000 | 1.071 |
Z | P |
320 | 10 Bar |
3,200 | 100 Bar |
3,790 | 120 Bar <Z> of all Oceans - depth of life Zone |
4,690 | 145 Bar depth of Mediterranean |
4,900 | 150 Bar maximum depth of life |
7,282 | 225 Bar depth of Gulf of Mexico |
20,000 | 600 Bar max. depth of Atlantic |
35,600 | 1100 Bar 1960 depth of Trieste into Chall.II (7 miles!!) |
Note: ratio of Volume of Ocean to Land (above Z=0) = 11
ratio of Area of Ocean to Land:
source: 1982 Encyclopedia Brittanica
Equations of motion
Momentum
Continuity
when motions are on the order of a scale height or less
Energy
FFT
Forward FFT
Inverse FFT
Forward Cosine transform
Inverse Cosine Transform
Gas Constant
<mw> gm/mole | Rgas J/gm/K | Cp J/gm/K | |||
Venus | 44.01 | 0.18892 | 0.8501 | 0.2222 | 1.2857 |
Earth | 28.96 | 0.28710 | 1.0040 | 0.2860 | 1.4005 |
Mars | 44.01 | 0.18892 | 0.8312 | 0.2273 | 1.2941 |
Jupiter | 2.22 | 3.74518 | 12.3591 | 0.3030 | 1.4348 |
Saturn | 2.14 | 3.89246 | 14.0129 | 0.2778 | 1.3846 |
Uranus | 2.30 | 3.61491 | 13.0137 | 0.2778 | 1.3846 |
Neptune | 2.30 | 3.61491 | 13.0137 | 0.2778 | 1.3846 |
Titan | 28.67 | 0.29000 | 1.0440 | 0.2778 | 1.3846 |
Geopotential
Geostrophic Approximation
Horizontal motions are in balance with the pressure gradient force. Friction is negligible ( i.e., far away from surface). Steady flow with small curvature ( i.e., dV/dt = 0 ). Works well for z 1 km, > 10°.
Gravity
<g> cm/s2 | <g> gearth | g(0) cm/s2 | g(45) cm/s2 | g(90) cm/s2 | |
Venus | 889.89 | 0.9082 | 889.89 | 889.89 | 889.89 |
Earth | 979.86 | 1.0000 | 976.81 | 981.29 | 987.16 |
Mars | 374.10 | 0.3818 | 372.40 | 374.90 | 378.10 |
Jupiter | 2425.61 | 2.4755 | 2256.64 | 2504.58 | 2833.44 |
Saturn | 1000.09 | 1.0206 | 882.36 | 1055.28 | 1283.11 |
Uranus | 880.07 | 0.8982 | 860.29 | 889.23 | 928.60 |
Neptune | 1110.46 | 1.1333 | 1087.16 | 1121.31 | 1167.07 |
Titan | 135.80 | 0.1386 | 135.80 | 135.80 | 135.80 |
106*J2 | 106*J4 | 106*J6 | 106*q | |
Venus | ||||
Earth | ||||
Mars | 1960.454 | |||
Jupiter | 14697 | -584.0 | 31.0 | 89180 |
Saturn | 16331 | -914.0 | 108.0 | 154766 |
Uranus | 3516 | -31.9 | 0.0 | 29513 |
Neptune | 4000 | 0.0 | 0.0 | 28960 |
Titan |
Hubbard and Marley (1989)
Kieffer
Heat Balance
If the eccentricity is equal to zero, e = 0, then
bond albedo | Fsun erg/s/cm2 | Fabs erg/s/cm2 | Pabs erg/s | Teq K | |
Venus | 0.750 | 2618462.8 | 163653.9 | 7.5299e+23 | 231.89 |
Earth | 0.306 | 1370000.0 | 237414.7 | 1.2110e+24 | 254.49 |
Mars | 0.250 | 590102.3 | 110447.6 | 1.5922e+23 | 210.18 |
Jupiter | 0.343 | 50616.0 | 8123.3 | 4.9933e+24 | 109.45 |
Saturn | 0.342 | 15011.7 | 2381.4 | 1.0167e+24 | 80.54 |
Uranus | 0.300 | 3691.7 | 641.0 | 5.1818e+22 | 58.01 |
Neptune | 0.290 | 1498.8 | 264.0 | 2.0141e+22 | 46.47 |
Titan | 0.220 | 15011.7 | 2927.3 | 2.4391e+21 | 84.80 |
Fint erg/s/cm2 | Pint erg/s | Fabs+Fint erg/s/cm2 | Teff K | out/in ratio | |
Venus | 0.0 | 0.0000e+00 | 163653.9 | 231.89 | 1.0000 |
Earth | 62.0 | 3.1624e+20 | 237476.7 | 254.51 | 1.0003 |
Mars | 0.0 | 0.0000e+00 | 110447.6 | 210.18 | 1.0000 |
Jupiter | 5440.0 | 3.3439e+24 | 13563.3 | 124.42 | 1.6697 |
Saturn | 2010.0 | 8.5815e+23 | 4391.4 | 93.85 | 1.8440 |
Uranus | 42.0 | 3.3953e+21 | 683.0 | 58.94 | 1.0655 |
Neptune | 433.0 | 3.3029e+22 | 697.0 | 59.24 | 2.6399 |
Titan | 0.0 | 0.0000e+00 | 2927.3 | 84.80 | 1.0000 |
Humidity
Absolute humidity
From the ideal gas law, the density of water, w is given bywhere <mw>w is the molecular weight of water (18.016 gm/mole), fw is a correction factor for non-ideal behavior which can be taken as fw = 1, e is the partial pressure of water, R* is the universal gas constant, and T is the local temperature.
Specific humidity
The total density, , is given by the sum of dry and moist densities ( i.e., assumes all other species are included in ``dry'').where <mw>d is the molecular weight of dry air (28.966), <mw>w/<mw>d = 0.62197, and (<mw>d - <mw>w)/<mw>d = 0.37803. The specific humidity is the ratio of the moist to total density and is dimensionless, but is usually expressed in gm/Kg units.
Note that
and the volumetric mixing ratio, f, (i.e., ratio of water number density, Nw, to the total number density Nt) is given by
where the average molecular weight, <mw>, is given by
Mass Mixing Ratio
Alt (km) | P (mB) | record low | 1% low | midlat. mean | 1% high | record high |
sfc | 1013.25 | 0.1 | 5.0 | 4,686 | 30,000 | 35,000 |
1 | 890 | 24.0 | 27.0 | 3,700 | 29,000 | 31,000 |
2 | 790 | 21.0 | 31.0 | 2,843 | 24,000 | 28,000 |
4 | 610 | 16.0 | 24.0 | 1,268 | 18,000 | 22,000 |
6 | 470 | 6.2 | 12.0 | 554 | 7,700 | 8,900 |
8 | 350 | 6.1 | 6.1 | 216 | 4,300 | 4,700 |
10 | 265 | 5.3 | 43.2 | 1,300 | ||
12 | 195 | 1.2 | 11.3 | 230 | ||
14 | 140 | 1.5 | 3.3 | 48 | ||
16 | 100 | 1.0 | 3.3 | 38 |
% Relative Humidity
where rs r(e = es) and qs q(e = es).
The saturated vapor pressure is approximately given by
where T is given in °C and a and b are constants.
a | b | |
above water | 7.5 | 237.3 |
above ice | 9.5 | 265.5 |
Dew Point Temperature
The Dew point is the temperature at which the partial pressure of water reaches the saturation value, that isThe empirical expression for es can be used or a table lookup can be utilized after e is calculated.
Hurricanes
Gale force winds | (> 15 m/s) |
Tropical Depression | (20-34kts and a closed circulation) |
Tropical Storm (named) | (35-64kts) |
Hurricane | (65+kts or 74+mph) |
knots | m/h | Ps,(mB) | inch.Hg | |
Category 1 | 64- 83 | 74- 95 | >980 | >28.94 |
Category 2 | 83- 95 | 96-110 | 965-979 | 28.50-28.91 |
Category 3 | 96-113 | 111-130 | 945-964 | 27.91-28.47 |
Category 4 | 114-135 | 131-155 | 920-944 | 27.17-27.88 |
Category 5 | >135 | >155 | <920 | <27.16 |
Note: 1 knot = 1 nautical mile/hour = 1.151555 mile/hour = 1.853248 Km/hr
Storm | Date | Cat | Pc | Rc | winds |
Nancy | Sep.12,1961 | 888 | 185 kt | ||
Tip | Oct.12,1979 | 870 | 85 m/s | ||
Camille | 1969 | 5 | 909 | 165 kt | |
Allen | 1980 | 165 kt | |||
Gilbert | Sep. 1988 | 888 | |||
Hugo | 1989 | 4 | |||
Andrew | 1992 | 4 | 922 |
Empirical formula for approximate energy, ergs, of a storm with a central
pressure, Pc, given in mBar and a radius of nearest circular isobar, Rc,
given in kilometers is
Hydrostatic Equilibrium
If the Ideal gas law holds (note: Rg = Runiv/<mw>), then
If the scale height is constant, then
Ideal Gas Law
where N is the total number of molecules, n is the total number of moles, Na = 6.02217 · 1023 molecules/mole, Runiv = 8.314 · 107 erg/K/mole, k = Runiv/Na = 1.380622 · 10-16 erg/K
IR filter bandpasses
µm | range | trans | thick | |
J | 1.25 | 1.1 - 1.4 | 60% | 2.0mm |
H | 1.65 | 1.5 - 1.8 | 60% | 2.0mm |
K | 2.20 | 2.0 - 2.4 | 60% | 1.5mm |
L | 3.82 | 3.5 - 4.15 | 60% | 1.0mm |
M | 4.70 | 4.4 - 5.0 | 60% | 1.0mm |
Latitude: planeto-graphic and planeto-centric
Planeto-centric latitude, and the planeto-graphic latitude,
If e = 0 then
CRC Standard Mathematical Tables 26th edition, pg. 129. The volume of an oblate sphere is equal to a sphere with radius <R>.
Req Km | Rpl Km | Req/Rpl | f | e | <R> Km | |
Venus | 6051.0 | 6051.0 | 1.000000 | 0.000000 | 0.000000 | 6051.00 |
Earth | 6378.5 | 6356.0 | 1.003540 | 0.003527 | 0.083920 | 6370.99 |
Mars | 3393.0 | 3375.0 | 1.005333 | 0.005305 | 0.102869 | 3386.99 |
Jupiter | 71492.0 | 66854.0 | 1.069375 | 0.064874 | 0.354316 | 69911.33 |
Saturn | 60268.0 | 54364.0 | 1.108601 | 0.097962 | 0.431658 | 58232.01 |
Uranus | 25559.0 | 24973.0 | 1.023465 | 0.022927 | 0.212906 | 25362.16 |
Neptune | 24820.0 | 24274.0 | 1.022493 | 0.021998 | 0.208597 | 24636.66 |
Titan | 2575.0 | 2575.0 | 1.000000 | 0.000000 | 0.000000 | 2575.00 |
Longitude Systems and conversion
P1 = reference rotational period of system #1
P2 = reference rotational period of system #2
L1(t-t0) is a known system #1 longitude relative to time t0
L2(t-t0) is the desired longitude value in system #2
relative to time t0
L21 is a reference longitude. It is defined as:
Jupiter
SI = 9h 50m 30.003s = 877.90°/24h. Used for equatorial motions.SII = 9h 55m 40.632s = 870.27°/24h. Used for mid-latitudes and GRS.
SIII = 9h 55m 29.711s ± 0.04s = 9.9249197h ± 0.000011h = 870.536°/24h ± 0.000966°/24h
where t0 = 2451545.0 TDB or Jan. 1.5, 2000.
Saturn
SIII = 10h 39m 22.4s ± 7s = 10.656222h ± 0.00194h = 810.7939024°/24h ± 0.148°/24hFor the Voyager encounters the reference time should be set to the closest approach time. Other possibilities are:
P1 | P2 | FDS(t=0) | L21 | |
Neptune | 17.866 | 16.11 | 11200.0 | -334.5365 |
Orbital: Equations of Motion
Orbits: Earth
where,
r(Km) | P(hr) | V(Km/s) | Vg(Km/s) |
200.0 | 1.474 | 7.786 | 7.549 |
400.0 | 1.542 | 7.670 | 7.217 |
700.0 | 1.645 | 7.505 | 6.763 |
900.0 | 1.715 | 7.401 | 6.486 |
35863.9 | 24.000 | 3.072 | 0.464 |
Planck function
The Planck function, B(T), is given by
where,
The brightness temperature, Tb, of a given radiance, R,
is found with the inverse of the Planck function.
The derivative of the Planck function is given by
Infrared approximation: for 600 cm-1 and
T 300 K.
Microwave Rayleigh Jeans approximation: (mm) = 300/f, = f/30 cm-1, f is in GHz
Wavenumbers, , are frequency units and are assumed to be in
vacuum while wavelength is the wavelength specified within the
medium. Typically, wavelengths are expressed as wavelength in air,
a or wavelength in vacuum, v.
f | cm-1 | µm | mm | |
0.66 GHz | 0.02 | 454545 | 454.55 | P band (SAR) |
1.25 GHz | 0.04 | 240000 | 240.00 | C band (SAR) |
5.33 GHz | 0.18 | 56285 | 56.29 | L band (SAR) |
6.6 GHz | 0.22 | 45454 | 45.45 | MIMR (surface) |
23 GHz | 0.77 | 13043 | 13.04 | AMSU-A |
50 GHz | 1.67 | 6000 | 6.00 | AMSU-A |
60 GHz | 2.00 | 5000 | 5.00 | AMSU-A |
89 GHz | 2.97 | 3371 | 3.37 | AMSU-C |
118 GHz | 3.93 | 2542 | 2.54 | MHS-X |
183 GHz | 6.10 | 1639 | 1.64 | AMSU-B |
wavelength mm | frequency GHz | B(T=300K) mW/m2/ster/cm-1 | dB/dT mW/m2/ster/cm-1/K | (1/B) · dB/dT %/K |
6.0 | 50 | 0.007 | 0.000023 | 0.335 |
3.0 | 100 | 0.027 | 0.000092 | 0.336 |
2.0 | 150 | 0.061 | 0.000207 | 0.337 |
1.5 | 200 | 0.109 | 0.000368 | 0.338 |
wavelength µm | wavenumber cm-1 | B(T=300K) mW/m2/ster/cm-1 | dB/dT mW/m2/ster/cm-1/K | (1/B) · dB/dT %/K |
16.7 | 600 | 153.38 | 1.559 | 1.0 |
9.1 | 1100 | 81.49 | 1.441 | 1.8 |
6.2 | 1600 | 22.69 | 0.581 | 2.6 |
4.3 | 2300 | 2.35 | 0.086 | 3.7 |
3.7 | 2700 | 0.56 | 0.024 | 4.3 |
3.3 | 3000 | 0.18 | 0.009 | 4.8 |
Planetary Missions
Mars
Outer Planet Mission Summary
Planet | Craft | Date | Julian | Ls |
Jupiter | Pioneer 10 | 12/ 3/73 | 2442019.5 | 1.4 |
Pioneer 11 | 12/ 2/74 | 2442383.5 | 33.9 | |
Voyager I | 3/ 5/79 | 2443937.5 | 170.4 | |
Voyager II | 7/ 9/79 | 2444063.5 | 180.4 | |
Saturn | Pioneer 11 | 9/ 1/79 | 2444117.5 | 354.1 |
Voyager I | 11/12/80 | 2444555.5 | 8.9 | |
Voyager II | 8/25/81 | 2444841.5 | 18.4 | |
Uranus | Voyager II | 1/24/86 | 2446454.5 | 271.3 |
Neptune | Voyager II | 8/25/89 | 2447753.5 | 243.3 |
Potential Temperature
Derived directly from integration of the 1st law
of thermodynamics. It is the temperature
a parcel of air at P and T would have if it were at Ps. It is
conserved for adiabatic motions, ( i.e., d/dt = 0).
For earth = 0.286 (<mw> = 28.96, Cp = 1.004 Joules/gram/K). Some authors write this equation with = Cp/Cv = 1/(1-)
therefore,
if H(z) = H0
Potential Vorticity
For adiabatic motion ( i.e., is
a constant) the density is = P(Cv/Cp). For motions
between layers of constant
In the Shallow Water Model, where is a constant ( i.e., incompressible), the conserved quantity is usually written as:
example : flow over a mountain
<u> is eastward (westerly) then flow turns towards equator as it passes mountain, then oscillates around original latitude.
<u> is westward (easterly) then flow turns equatorward (note flow turning poleward `bucks' the flow causing it to turn equatorward. System is returned to original latitude after it passes mountain. No oscillations.
Radiative time constant
The volumetric heating rate, Q
Harshvardan and Cess (1976, Tellus 28 p.1-10) give a value for Earth CO2 of / z = -0.0081 per Km and Cess and Khetan (1973, JQSRT 13 p.995-1009) give a value for Jupiter, Saturn, Neptune, and Uranus of / z = -0.0068, -0.0063, -0.0061, and -0.0058 per Km, respectively.
The phase shift, , is the seasonal lag due to the radiative time constant. It arises from the 1st Fourier moment of the thermal response. A value of =90° indicates a full seasonal shift ( e.g., the warm maximum expected at the summer solstice would occur at the autumnal equinox).
where o is the orbital period. For = 0.3 the values are:
Teff K | Peff mBar | gm/cm3 | H Km | rad years | phase ° | |
Venus | 229.0 | 20.000 | 4.6230e-05 | 4.862 | 0.007 | 3.94 |
Earth | 255.0 | 500.000 | 6.8297e-04 | 7.471 | 0.131 | 39.47 |
Mars | 210.0 | 6.000 | 1.5124e-05 | 10.605 | 0.006 | 1.17 |
Jupiter | 124.0 | 400.000 | 8.6132e-05 | 19.146 | 4.534 | 67.39 |
Saturn | 95.0 | 300.000 | 8.1128e-05 | 36.975 | 20.794 | 77.27 |
Uranus | 59.0 | 430.000 | 2.0161e-04 | 24.234 | 131.311 | 84.15 |
Neptune | 59.0 | 500.000 | 2.3443e-04 | 19.206 | 121.008 | 77.67 |
Titan | 85.0 | 1.000 | 4.0568e-06 | 18.152 | 0.053 | 82.54 |
Radiative transfer Equation
Bi(T) is the Planck function evaluated at the effective
channel wavenumber.
Hi is the channel averaged solar irradiance at the top of the atmosphere.
0 is the local zenith angle of the Sun.
'i is the channel averaged two path transmittance from the Sun to the surface to the satellite.
ui(p) is the atmospheric transmittance measured
between p and the top of the atmosphere for channel i.
di(p) is the atmospheric transmittance between p and the surface for channel i.
Explicit retrieved parameters
i is the surface emissivity at i.
Ts is the surface temperature.
T(p) is the surface temperature profile.
i is the surface spectral reflectivity at i.
'i is the surface spectral bidirectional reflectance
of solar radiation at i.
Implicit retrieved parameters ( i.e., within
i and 'i).
CO2(p) is the carbon dioxide profile.
q(p) is the humidity (water) profile.
O3(p) is the ozone profile.
CO(p) is the carbon monoxide profile.
CH4(p) is the methane profile.
NO2(p) is the nitrogen dioxide profile.
Rayleigh Scattering: Optical Depth
The average scattering cross section per particle is given by
where, n is the index of refraction, N0 is the number of molecules per unit volume at standard temperature and pressure ( i.e., conditions of index of refraction), is the depolarization factor.
The optical depth can be related to the ``thickness'' of the
atmosphere.
If Z is the thickness in Km-amagats then:
The index of refraction has a wavelength dependence. This is usually represented by two constants, A and B, as follows:
The wavelength dependence in the VIAMP code is taken from Dalgarno and Williams (ApJ, 1962). This equation is similar to the equation above, however, it differs in the 8 term.
The optical depth per Km-amagat of hydrogen, denoted by 1(H2), is then
And the total optical depth for a mixture of gases is given as
Note that this formulation always uses the wavelength dependence of hydrogen, even if other gases are used.
ray | n | A (10-5) | B (10-3) | (10-24) | a0 µm4/Km | ||
air | 4.4459 | 1.0002918 | 28.71 | 5.67 | 3.40 | 0.031 | 10.7E-4 |
H2 | 1.0000 | 1.0001384 | 13.58 | 7.52 | 1.61 | 0.02 | 2.35E-4 |
He | 0.0641 | 1.0000350 | 3.48 | 2.30 | |||
O2 | 3.8634 | 1.000272 | 26.63 | 5.07 | 0.054 | ||
N2 | 4.6035 | 1.000297 | 29.06 | 7.7 | 3.44 | 0.030 | 10.9E-4 |
H2O | 3.3690 | 1.000254 | |||||
CO2 | 10.5611 | 1.0004498 | 43.9 | 6.4 | 0.09 | ||
CO | 5.8247 | 1.000334 | 32.7 | 8.1 | |||
NH3 | 7.3427 | 1.000375 | 37.0 | 12.0 | |||
NO | 4.6035 | 1.000297 | 28.9 | 7.4 | |||
CH4 | 10.1509 | 1.000441 |
The depth of penetration of Rayleigh scattering is computed for various objects using the data above. A summary of the characteristics of the plots in Figure 9 is given below (g is gravity in cm/s2, µ = molecular weight in gm/mole, Z = KM-amagats per Bar).
wave(µm): | 0.1000 | 0.2000 | 0.2640 | 0.3000 | 0.4000 | 0.5000 |
(P0): | 209.57 | 6.95 | 2.05 | 1.19 | 0.36 | 0.14 |
P(=1): | 4.8 | 145.7 | 493.2 | 851.0 | 2834.7 | 7094.5 |
wave(µm): | 0.1000 | 0.2000 | 0.2640 | 0.3000 | 0.4000 | 0.5000 |
(P0): | 299.82 | 8.62 | 2.47 | 1.42 | 0.42 | 0.17 |
P(=1): | 3.3 | 116.1 | 405.2 | 706.3 | 2390.8 | 6030.4 |
wave(µm): | 0.1000 | 0.2000 | 0.2640 | 0.3000 | 0.4000 | 0.5000 |
(P0): | 754.31 | 21.68 | 6.21 | 3.56 | 1.05 | 0.42 |
P(=1): | 1.3 | 46.1 | 161.0 | 280.7 | 950.3 | 2396.9 |
wave(µm): | 0.1000 | 0.2000 | 0.2640 | 0.3000 | 0.4000 | 0.5000 |
(P0): | 5378.65 | 152.59 | 43.58 | 24.98 | 7.37 | 2.92 |
P(=1): | 0.3 | 9.8 | 34.4 | 60.1 | 203.6 | 513.9 |
The gas continuum absorption contains a term which is supposed
to represent the effect of Raman scattering due to the 1 vibration
of H2 at 4161 cm-1.
Ref.: Belton et al. (1971). Atm. of
Uranus. ApJ. 164, 191-209
Rayleigh Scattering: Phase Function
Definitions of Angles
See Figure 11. The angle between the incident flux and the
local normal is given by and µ0 cos().
The angle between the local normal and the observer is given by
and µ cos(). The phase angle,
, is the angle between the incident and emission through the
origin. The azimuthal angle, , is the projection of the
solar incidence and emission directions onto the local horizon. Using
spherical trigonometry cosine laws (e.g., see CRC pg. 146) we can
easily obtain the value of ) given µ0, µ, and . For solar scattering to an observer above the atmosphere the
angles are related by:
This is the method employed by Chandrasekar, Liou, and others.
We could also write the equations in terms of the scattering angles.
The scattering angle between incidence and emission, , which
is related to the phase function, is given by = - .
The scattering angle in the horizontal plane, is related
to the azimuthal angle, and is given by = - . This definition is used by Hansen, Tomasko, and Danielson.
It is the method employed within the VIAMP programs. Note the sign
change between the two methods.
The Rayleigh phase function is given in terms of scattering
angles or phase angles by
The cos2 term can be expressed in terms of µ, µ0, and as
So the Rayleigh phase function can be written in terms
of 3 Fourier moments:
where the 3 coefficients are equal to
Richardson Number
Dynamically significant stability indicator (similar to
Burger number). As Ri --> 0 convection becomes strong.
when the Rossby Number, Ro 1 then the static stability buoyancy frequency, N = Ri/Ro. When Ro 1, N = Bo/Ro
Stone 1972 JAS 29 p. 405. For Jupiter: d /dz = 6.0 · 10-10 K/cm and du/dz = 3.8 · 10-4 cm/s, then Ri = 3.7 · 10-3
Rossby Number
A small Rossby number indicates that the geostrophic
approximation is valid ( i.e., du/dt = dv/dt = 0) and
that the Coriolis acceleration, v · f, is greater than
the horizontal fluid acceleration, du/dt.
For the GRS, hurricanes, etc.
where Vt is the tangential velocity, a is the semimajor axis, b is the semiminor axis, and is the angle between the semi-major axis and the direction of motion. Mitchell et al. 1981 JGR 86 p.8751.
terrestrial | Red Spot | FA/BC/DE | small spots | |
Vt | 110 m/s | 120 m/s | ||
a | 1.1E7 m | 4.9E6 m | ||
Ro(0) | .36 | .36 | ||
Ro(90) | .04 | .08 | ||
g.lat | 22 S | 33 S | 40.5 S |
Saturation Vapor Pressure
Given T in Kelvin these equations will give es in milliBar.
from Fleagle and Businger, Vol.5, pg. 62 (QC880.F59)
The first law can be written as
where 1 1/1 and index 1 refers to the liquid phase and index 2 refers to the gas phase.
For an isothermal change of phase, the Clausius-Clapeyron
equation has the form
Water vapor behaves like an ideal gas and 2 1 for a change in state.
at triple point all 3 phases can exist in equilibrium, 0.0098° C and Ps = 6.11 mB
Undocumented fit is used in the program watsat.F (over liquid)
Note this is the same equation as above, except that it assumes L = 2485.2 Joules/gm and T0 = 273.15 ° K
Another undocumented fit is given (but not used) in the program watsat.F
coef | over ice | over water |
a | -5631.1206 | -2313.0338 |
b | -8.363602 | -164.03307 |
c | 8.2312 | 38.053682 |
d | -3.861449 · 10-2 | -1.3844344 · 10-1 |
e | 2.77494 · 10-5 | 7.4465367 · 10-5 |
From Rogers and Yau, pg. 16
coef | Rogers & Yau over water |
a | 17.67 |
b | 29.66 |
Murray, F.W. 1966. ``On the computation of Saturation
Vapor Pressure'' J. Appl. Meteor. 6 p.204
coef | Murray over ice | Murray over water |
a | 21.8745584 | 17.2693882 |
b | 7.66 | 35.86 |
Saucier, W.J. 1883. ``Principles of Meteorological Analysis'' Dover pg. 9 who uses values of Tetens (1930). Note, he used 10[(a'T)/(T-b')] with T in Centigrade so to convert into the form above a = log 10 · a' and b = 273.16-b'.
coef | over ice | over water |
a | 21.875 | 17.27 |
b | 7.66 | 35.86 |
Thermal Wind Equation
Relationship between meridional temperature gradient
and vertical wind shear due to non-uniform horizontal
heating. Note: dy = Re · d. Hydrostatic and
geostrophic balance yields:
Velocity of sound
Vorticity
Relative vorticity tend to be conserved in
storm systems.
Absolute vorticity tends to be conserved
following the motion ( i.e., forecasting).
If is positive then it is cyclonic and if
is negative then anti-cyclonic.
Weighting Functions
The outgoing radiance or upward radiance, Ru, for channel i
from an atmospheric column is given by
The weighting function is defined as
and the contribution function is the integrand of the outgoing radiance calculation
and can be normalized as
the information content will require derivative w.r.t. temperature of the radiation transfer equation and, therefore, the Kernel function represents the best estimate of the sounding level for temperature retrievals.
Wind Measurement
The meridional velocity is the distance, r · , divided by the time difference, t. Since the radius
is given in Km's and the time is given in hours we need factors of
1000 and 3600, respectively, to convert to meters per second. If
is given in degrees then:
To calculate the zonal velocity we need to calculate the displacement along a latitude circle, (i.e., / 360), during the time interval t.
Alternatively, we can calculate the period of rotation of the measured feature, P, and define the wind relative to the system of measure, Pref as follows:
so that,
Encyclopedia Author-Chris Barnet
HTML Editor-Steve Duran
Please E-mail Lyle Huber for any comments or suggestions.
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