Lecture: August 26, 8:00-9:30 am

Prof. Dr. Gerrit Lohmann

Exercises: August 26, 9:40-10:30 am

Dr. Lu NIU


UNESCO/IOC-RTRC-ODC Training Course on Prediction and Projection of Climate

First Institute of Oceanography, Qingdao, China




1) Lecture (preliminary)

topics: Holocene, abrupt climate change, long-term variability, ocean circulation, …

Lecture Orbital Theory 1

Lecture Orbital Theory 2

Lecture EBM

Exercises Energy balance model


2) Exercises

a) Insolation and orbital theory

Use the

Exercises Orbit:

  1. Calculate orbital parameters!
  2. Calculate annual insolation at a specfic latitude!
  3. Plot of insolation for the last 1 million years at 65°N !
  4. Calculate the spectrum of the time series ! (only for specialists)
  5. Calculate the space-time plot of insolation for 0 ky, 6 ky, 124 ky BP !
  6. Calculate the anomaly of 6 ky and 124 ky minus today !


b) Energy balance model and feedbacks

Use the model from here or there


Exercises Energy balance model (upper model)

  1. What will happen if the CO2 content in the atmosphere is doubled? Radiative forcing= 4 Wm-2
  2. What will happen if the factor γ is 1% higher/lower in the long-wave radiation?
  3. Describe the effect if the diffusivity is enhanced by a factor of 2!
  4. The coalbedo of sea ice can vary between 0.3 and 0.4. Describe the effect when varying the value!
  5. Write down the numerical scheme (time stepping etc. from the source code) !
  6. Show the evolution at one specific latitude and discuss it!



c) Aquaplanet EBM with seasonal cycle (lower model, only for specialists)

  1. What will happen if the CO2 content in the atmosphere is doubled?
    (Radiative forcing= 4 Wm-2= lowering of A )

  2. Discuss the sea ice evolution during the year !

  3. Reduce (enhance) the sea ice thermal conductivity by 20% mimiking more (less) snow on top of sea ice !

  4. Write down the numerical scheme (time stepping) !



Berger A., 1978 Long-term variations of daily insolation and Quaternary climatic changes. Journal of Atmospheric Science, 35(12), 2362-2367.

Huybers, P. and I. Eisenman, 2006. Integrated summer insolation calculations. NOAA/NCDC Paleoclimatology Program Data Contribution #2006-079.

Lohmann, G., 2020 Climate Dynamics: Concepts, Scaling and Multiple Equilibria. Lecture Notes 2020, Bremen, Germany.

Lohmann, 2020 Temperatures from energy balance models: the effective heat capacity matters, Earth Syst. Dynam., 11, 1195–1208.

Wagner and Eisenman, 2015 How Climate Model Complexity Influences Sea Ice Stability. Journal of Climate.