1. ATOC 4720: class 16 Entropy Entropy Generalized statement of the Second Law of thermodynamic Generalized statement of the Second Law of thermodynamic Atmospheric aerosol Atmospheric aerosol Effects on atmospheric phenomena Effects on atmospheric phenomena

2. Carnot cycle: 4 steps Begins at A Q1 Q2 Heat is transferred from warmer (H) to colder (c) body

3. Efficiency: Hot to cold: Heat can not by itself transfer from cold to hot

4. Entropy

5. The ratio Stays the same no matter Which isotherm is chosen in passing from one adiabat to anotoher. Therefore, Is a measureof the difference between the two adiabats; It is called the difference in Entropy (S).

6. We define: As the increase in entropy S. Unit mass: The first law of thermodynamics:

7. We can derive that: Transformations in which the entropy remains constant (and therefore potential Temperature remains constant) are called Isentropic.

8. T-entropy (S) diagram Work done

9. Generalized statement of the second law of thermodynamics Up to now: ideal reversible, equilibrium 1. There exists a function of state for a body called entropy s; 2. S may change (due to thermal conduction) Or as internal change

10. 3. 4. For reversible process For nonreversible: Reversible: Nonreversible:

11. 3. Aerosols

12. Total concentration

13. Size spectra