deMenocal and Rind Questions

1. What is latent heat?

The heat that is either released or absorbed by a unit mass of a substance when it undergoes a change of state, such as during evaporation, condensation, or sublimation.

http://earthobservatory.nasa.gov:81/Library/glossary.php3?xref=latent%20heat

2. What is the Clausius-Clapeyron equation and what does it effect?

The vapor pressure of a liquid increases as the temperature increases. This is why puddles left after a rainstorm evaporate faster on a hot day than on a cold day.

The vapor pressure of a liquid increases faster as the temperature nears the boiling point of the liquid- the data is not a straight line. However, it turns out that the plot of the log of the vapor pressure vs. 1/T is a straight line with a slope equal to that of -DHvap/R. We can use this fact to derive a simple equation that relates the vapor pressure at certain temperatures to the heat of vaporization, the Clausius-Clapeyron equation.

http://learn.chem.vt.edu/tutorials/lsproperties/clauclap.html

3. What are the two patterns of variability in response to high-latitude climate change that have been described in low-latitude paleoclimate records?

  • precipitation variation: lake levels, Nile outflow, NW Africa eolian dust, equatorial Atlantic upwelling (McIntyre and Molfino), Asian monsoon intensity all vary with precessional forcing
  • other marine records of eolian dust, pollen, grass cuticle abund. and lake level and terrestrial vegetation records vary with obliquity and eccentricity, suggesting a high-latitude origin

4. What are the differences between the climate that the model produces and what is actually observed in the real world?

  • winter SLP between Asian high and Indian Ocean low 30% too strong
  • ne trades are too week and southward of their present position
  • too much winter precipitation in s. Asia and excess precip in Bay of Bengal
  • summer monsoon rains don't penetrate Himalayas sufficiently

5. What are the effects of various forcing factors (insolation, ice cover, North Atlantic SST, Asian orography) on the African monsoon?

The most important influence on the African monsoon is variation in North Atlantic SST. Variation in insolation and ice sheet volume have secondary importance. Changes in Asian orography have no discernible effect. This is almost the inverse of the importance of all these factors regarding the Indian monsoon.