1. * Reading Assignments:
All sections

2. 7. Hydrostatic Equilibrium
7.1 Effective gravity
Radial gravitation
by the planet’s mass
Centrifugal acceleration due to
rotation of the reference frame
Anisotropic contributions

3. 7.2 Geopotential and Geopotential height
is the specific work performed against gravity to displace
a unit mass of air parcel from the sea level to a height of Z.
* Geopotential height
is nearly identical to geometric height, but has different physical
meaning.

4. 7.3 Hypsometric equation

9. 7.4 Stratification of environment
The environmental lapse rate:
* Layer of constant lapse rate

11. * Isothermal Layer
* Layer of Homogeneous Density

12. One meteorology station is located at 250 m above
the sea level. When it measures the pressure and
temperature at 982 hPa and -12oC, another station
has the pressure and temperature at 975 hPa and
-14oC. What is the height of the this station above
the sea level?

13. 2. One of the weather map is the 1000-500 mb thickness map.
The contour lines represent the distance between these two
pressure surfaces.
a) Use the hydrostatic equation to derive a relationship between the
mb thickness and the average temperature in the layer of
mb.
b) The mb thickness is predicted to increase from 5280m to
5460m at a given station. Assuming that the lapse rate remains
constant, what change in surface temperature would you predicted?
(Assume the amount of moisture in the air does not change.)

14. 3. A moist air parcel initially is at 500 m
3. A moist air parcel initially is at 500 m. Due to the advection, the pressure of this air parcel decreases 20 mb. Find if there is cloud forming during this process. Assuming the process is adiabatic; the vapor pressure of the air parcel is 8 mb at 500m and remains constant. The vertical distribution of atmospheric pressure and temperature are
respectively, where P is in mb, T in K, and z in m.

15. 7.5 Lagrangian Interpretation of stratification
Describing the atmospheric stratification in terms of the behavior
of individual air parcels
Adiabatic Stratification
* For unsaturated moist air
The atmospheric potential temperature is uniformly distributed
with height,
The environmental lapse rate is constant and is equal to the
dry adiabatic rate,

17. 7.5.2 Diabatic Stratification
Air parcels interact with the environment through the heat transfer
when they move both horizontally and vertically.
When the atmospheric temperature increases with height,
the potential temperature increases with height.

19. Meteorology 341
Homework (7)
1. Using the following sounding records, calculate the virtual temperature (Tv) and
height correspond to each pressure level. The surface pressure, temperature and
mixing ratio are 1008mb, 21.9 oC, and 9.6 gkg-1 , respectively.
P (mb) T (oC) q (gkg-1) Tv (K) z (m)
2. On a certain day, the atmosphere has a temperature T0 of 20oC and a pressure
p0 of 1000 hPa at the surface (z0=0). The lapse rate is 0=6 K/km from the surface
to 3 km altitude; 1=3 K/km from 3 km to 6 km altitude. Find the pressure p at an
altitude of 5 km.
3. A moist air parcel initially is at 500 m. Due to the advection, the pressure of this
air parcel decreases 20 mb. Find if there is cloud forming during this process.
Assuming the process is adiabatic; the vapor pressure of the air parcel is 8 mb at
500m and remains constant. The vertical distribution of atmospheric pressure and
temperature are respectively.
4. Problem 7 on page 169