1. OCN 5401 Chapter 3 Heat Transfer Instructor: Dr. George A. Maul gmaul@fit.edu / X 7453

2. Heat Flux (W·m -2 = J·s -1 ·m -2 ) Q s – radiation from the sun Q b – back radiation from Earth Q e – evaporative heat loss or gain Q h – sensible heat loss or gain Q v – advective heat loss or gain Q t = Q s – Q b – Q e – Q h – Q v James Prescott Joule, FRS

3. Radiation Paths reflected refracted absorbed scattered transmitted V1V1 V2V2 Index of Refraction (η 2 /η 1 ) = V 1 /V 2 η water-air = 1.333 (at 20°C) irradiance Willebrord Snell

4. Solar Spectrum Max Planck

5. C SUN : What is the solar constant? where If T SUN = 5775K, C SUN = ? Distributed solar irradiance at top of atmosphere (MJ/m 2 /day) Solar irradiance

6. The solar constant isn’t constant! SOHO UV images of 11 year solar cycle Note the sunspots

7. Albedo

8. Distribution of Water and Land Solar Heating Inflow = Outflow C SUN (1-A)πr 2 = 4πr 2 σT 4 If A=0.3 and C SUN =1367 W·m -2, what is T=?

9. Earth’s mean temperature balance requires an extra term Q GHE : What is the greenhouse effect? T Earth : What is Earth’s temperature? A: Is Earth’s albedo fixed?

10. How would Earth’s temperature change if the albedo changed from 30% to 29%? minus If T EARTH(A=30%) = 288K, T EARTH(A=29%) = ?

11. Relative Humidity (RH) and Saturation Vapor Pressure (e s ) Example: RH = ? T air = 30°; T dew point = 10° e s = 39 mb; e air = 12 mb

12. Evaporation from the Sea Surface Q e = ρ water E·L Evaporation (E) is in meters per second, and latent heat of evaporation (L) is L= 2495 x 10 3 J·kg -1 Evaporation minus precipitation in millimeters per day

13. Seasonal Thermocline and Mixed-Layer Depth

14. Earth Remote Sensing

15. Passive Microwave Remote Sensing SSM/I – Special Sensor Microwave Imager microwave brightness temperatures at 19.35, 22.2, 37.0, and 85.5 GHz

16. Sea Ice Variability

17. Sea level from satellite altimetry (active microwave sensing)

18. Infrared Satellite Imagery Infrared Image

19. Upper few millimeters of the sea surface

20. Sea Surface Temperature (SST) Skin Temperature and Bulk Temperature

21. OCN 5401 Questions? Chapter 3