1. LGM Seasonal Energetics October, 2009

2. Annual mean insolation Reflects Obliquity Change Only (Modern = 23.45 LGM = 22.95)

3. TOA seasonal incoming Insolation Primarily reflects obliquity (precession change from 102 in modern to 114 in LGM), biggest high latitude effect in summer

4. Insolation Changes Solid = Land average, Dotted = Ocean Average

5. Absorbed Solar Radiation High Latitude summer changes dominate

6. ASR by components ASR = Incoming_SW – outgoing_SW Outgoing = what never makes it surface + reflected by surface + residual What never makes it to surface = downwelling_TOA – downwelling_Surf---- this could be absorbed or reflected but lets assume it’s reflected by atmos reflected by surface = upwelling_Surf Res = up_TOA - what never makes it surface – upwelling surface The residual includes the absorbed (and scattered) downwelling and the upwelling radiation that is absorbed, reflected in the atmos (res = approx. 20% incoming, fairly spatially uniform)

7. ASR by components- all signs are gain to atmosphere Solid = incoming / Dashed = surface / dotted = atmosphere Dashed dot are residual (small)

8. ASR by components- all signs are gain to atmosphere Solid = NET (all terms) / Dashed = surface albedo / dotted = atmosphere Large but not total compensation between the atmos and surface

9. What never makes it to surface (atmos) by components Total = downwelling_TOA – downwelling_Surf Clear = downwelling_TOA – down_SURF_clear Cloudy = down_SURF_clear – down_Surf

10. Atmosphere’s effect on ASR change Signs are defined such that positive mean atmos gains LGM - MOD

11. More clouds = more reflection July- LGM - MOD Change in radiation REFLECTED (+ = more LGM up) SW July LGM – MOD Cloud liquid water (vert. Int. in kg) change

12. More clouds = more reflection JAN- LGM - MOD Change in radiation REFLECTED (+ = more LGM up) SW JAN LGM – MOD Cloud liquid water (vert. Int. in kg) change Cloud changes could be multiplied by incoming solar to try And tease out the change in reflected--- if we care

13. Surface Changes- Land Ocean Solid = Land Domain / Dotted = Ocean Domain

14. Atmospheric ASR changes/ Land-Sea Solid = Land /Dotted = Ocean Note; this is atmos contribution to total ASR, not ASR in the atmos Necessarily (could be atmos albedo change)

15. SURFACE HEAT BUDGET annual mean LGM surface LW goes up despite lower temperature- must Be because atmos has more vapor

16. SURFACE HEAT FLUX – OCEAN Domain Positive = to the atmosphere- LGM has smaller seasonal heat flux In both hemisphere’s because of more extensive sea-ice- NA is weird Bottom Plot Takes Into Account Change in Land Frac In LGM

17. SURFACE HEAT FLUX – LAND Domain Positive = to the atmosphere Bottom is an order of magnitude smaller than ocean

18. FS Change LGM gets more heat from ocean in NH winter NOT sure abour SH Land changes

19. Where does the LGM atmosphere get additional winter heat from? JFM FS (colors in W/m^2) and sea Ice concentration MODERN LGM

20. JFM FS change (LGM-MOD) SEA ICE is from LGM

21. JFM FS change- define regions of interest Composite around regions of large FS change Where does the energy come from

22. Composite FS seasonal cycles North Atlantic Regions Each region changes its annual mean FS- consequence of uncoupled Run? Are there really large ocean heat transport changes

23. North Atlantic Feb. FS and TS Solid = Modern, Dashed = LGM Sea ice edge has large FS gradient, leads to large temp. grad Temp. grad reverses north of Ice edge

24. Global Mean Energetics Solid = PI (CAM)/ Dashed = LGM / Dotted = Observations Should we be worried about model-observation difference?

25. 3 Box Surface Temp. Elevation change in LGM is a potential issue Larger LGM high latitude seasonal cycle

26. 3 Box Atmos Temp. Elevation change in LGM is a potential issue Slightly Larger LGM high latitude seasonal cycle

27. 3 box temp- amplitudes Seasonal Temp. Amplitude

28. 3-BOX_Energies SOLID = MODERN / DASHED = LGM / Dotted = 4 X co2 LGM polar region has less seasonality in ASR (albedo is higher) but Equally large changes in FS

29. 3 BOX energy changes (LGM/quad-PI) SH has smaller ASR amplitude but even smaller MHT variability, so the OLR and MHT amplitude up NH Summer changes dominate LGM – PI Is SOLID Quad – PI Is dashed

30. 3 box seasonal amplitudes (ASR-FS) is the energy fluxed to the atmosphere. Seasonal cycle ASR goes down in the LGM(enhanced albedo) but so does FS, so the energy fluxed to the atmosphere is unchanged. The partitioning of that energy between OLR and MHT is interesting.

31. 6 box energies- PI (cam) and obs Solid = observations / dashed = modeled

32. 6-box temperatures- TS

33. 6-box temperatures- TV

34. 6 box temp amplitudes

35. 6-box energies- **SAME LAND MASK** (modern grid boxes with >95% LFRAC) LGM = dashed/ MOD =Solid Less energy into LGM Ocean = more energy into LGM atmos over ocean = larger temp variability over ocean -> less zonal heat transport to the land -> larger seasonal cycle over land Solid =PI Dashed = LGM Dotted = quad

36. 6-box energies- LGM/quad-PI

37. Land Domain Seasonal Amplitudes Less LGM ASR cycle- but less energy is exported zonally because ocean temps. Have a larger seasonal cycle. The energy accumulated over land doesn’t change much Total energy accumulated = MHT, OLR, and CTEN (quadrature) variability ZHT To land Is out Of phase With ASR

38. Ocean Domain Seasonal Amplitudes Note- ASR and ZHT are in phase over ocean

39. Change in non-open ocean

40. Diffusive heat transport Start with zonal mean vertically averaged temp MOD = RED / LGM =BLUE– solid=raw / dashed = trunc. Legendre exp. Not many zonal mean differences beyond the global mean I interpolate Below the Topography To make A vertically Integrated Temp record That isn’t biased By topography (I think)

41. Heat transport divergence MOD = RED / LGM =BLUE– solid=raw / dashed = trunc. Legendre exp. Not many zonal mean differences

42. Legendre Fourier expand temp and MHT_div

43. LGM –MOD legendre four. Coef.s Stronger annual mean temp. grad. In LGM. Seasonal changes are more Complex; Annual mean heat flux changes also up in LGM

44. Back out D Not all wavenumbers fall on a line of constant D- BUT the #2 in the LGM and MOD do- D/a^2 =.98

45. Reconstruct HT, from T and D D is held constant, from the mod Wave#2 fit- SH placement is off T is Truncated At wave# 6

46. Reconstruct HT from T and D

47. MAX HT reconstruct

48. B_mht from 3 box models - TV B_MHT values are 3 +/-.4 (2 sigma) and 2 +/-.1 for NH and SH We used 3.4 in EBM; R^2 are.86 and.89 for NH and SH

49. B_mht from 3 box models -TS B_MHT values vary widely between models- however R^2 values are Slightly better and =.87 and.91 for NH and SH

50. B_olr from 3 box model Asterisk =NH Square = SH Solid = NH Linear Dashed = SH Linear

51. Zonal mean temperatures

52. Meridional Cross Section Temp.

53. Delta Meridional Cross Section Temp.

54. Zonal Mean Seasonal Amplitude Temp.

56. Zonal mean specific humidity (OCEAN DOMAIN ONLY)

57. Delta Zonal mean specific humidity (OCEAN DOMAIN ONLY)

58. PERCENT Delta Zonal mean specific humidity (OCEAN DOMAIN ONLY)

59. Summer – winter LW heating (JJA –DJF NH and DJF-JJA SH) LW heating OPPOSSES the seasonal cycle

60. Quad – pi change in annual mean LW heat In general, counters the mean state change- convection does that

61. Seasonal amplitude LW heating

62. Quad – PI seasonal amplitude LW