**(Question 1)**

Concept Plan for Getting Answer to Question: *how will temperature change at San
Francisco due to temperature advection alone.*

**Governing Expressions**

The governing equations tell us what we need
to know. To find the forecast
temperature, we use the expression that relates the initial temperature to the
final temperature by the change in temperature due to advection.

The change in temperature due to advection is
calculated from a map that shows temperature gradients and wind.

Here are the two expressions.

(Equation
1)
T_{f} = T_{i }+ (DT)_{advection}

(Equation
2) (DT)_{advection} = **-**V
(DT/Ds) (Dt)

**Need to Know**

For Equation 1, Need to know
T_{i}, and Delta T (from Equation 2)

For Equation 2, Need to know V, Delta t and (DT/Ds)

Given:

(a) T_{i} = 15^{o}C

(b) V = 100 km /h

(c) Delta t = 1 h

(d) Delta s = 100 km

For Delta T/Delta s = [T_{2} – T_{1}]/Delta s need to know (figure 1):

(e) T_{2} = 15^{o}C

(f) T_{1} = 30^{o}C

**(Question 2)**

**Procedure**

Put
(b), (c), (d), (e) and (f) into equation (2) to obtain

(DT)_{advection} = - (100 km /h)( [15^{ o}C – 30^{
o}C]/100 km)( 1 h)

(g) (DT)_{advection}=
+15^{ o}C

Put
(g) and (a) into equation (1)

T_{f}
= T_{i }+ (DT)_{advection}

T_{f}
= 15^{o}C+15^{o}C = 30^{o}C

**Results Analysis**

Here
you examine the result and decide if it is physically realistic given the
constraint of the problem. This
one is easy. You already know that if the air parcel at A moved to San
Francisco the person at San Franciso would notice that the temperature would go
up to 30^{o}C by looking at Figure 1.

If
your answer was a temperature fall, or that some unrealistic forecast
temperature would occur (like -40 or 154) then you know you messed up
somewhere.