Climate of the last 2 centuries: Constraints from the instrumental, documentary, and proxy data

1. Climate of the last 2 centuries: Constraints from the instrumental, documentary, and proxy data Alexey Kaplan LDEO of Columbia University In collaboration with: Liz Kent, Jesse Conan, Mike Evans, Mark Cane, Yochanan Kushnir

2. Trial reduced space OI analyses of basic COADS variables SST (with FP95 correction), SLP, winds, cloudiness, humidity; GHCN land station data: air temperature and precipitation. 4x4 degree monthly grid.Intercomparison of different variables and with paleo and documentary data.

3. Model for Bias in ship in situ SST [Kent and Kaplan, J. Climate, in press] Simple model for errors: Bucket SST error  air temp. - SST SSTbucket = SSTtrue + a(AT - SSTtrue) Engine intake SST has constant offset SSTengine intake = SSTtrue + b The solid line shows the actual difference between SST from engine intake and SST from buckets averaged over the period 1980-1989 in the North Atlantic. The dotted line is the modelled difference and the shaded area a 95% confidence interval. New Bayesian model for joint probability density function of a and b

4. Model for Bias in ship in situ SST (cont.) [Kent and Kaplan, J. Climate, in press] • Estimates of a (which gives the error due to heat loss in the bucket SST) remain fairly constant at ~15% over the period 1975-1994. • Estimates of b (which represents the offset in the engine intake SST) are ~ 0.1-0.2˚C in 1975 to 1989 (warm bias) • But in 1990-1994 the model shows b changes sign suggesting the engine intake SST is biased cold. • This would mean that both methods are biased cold in this period.

5. Difference between 2 OIs: ICOADS SST – GHCN air temperature Correlation coeff RMS diff 20th Century 19th century

6. I-COADS analyses Ocean model response to the wind analysis GHCN analysis

7. William Quinn’s criteria for El Niño events

8. William Quinn’s references for El Niño events chronologies

11. Historical chronologies vs instrumental and proxy ENSO indices

12. New instrumental indices of El Nino – Southern Oscillation (ENSO) Variable Abbr Definition Pacific Sea Surface Temperature PST Aug-Feb (180º-South American Coast, 10ºN -10ºS) Sea Level Pressure Difference PD Jul-Feb [(150ºE-80ºE, 30ºS-10ºN) - (70ºW-160ºW, 30ºS-18ºN)] Zonal Wind ZW May-Sept (130ºE-180º,10ºN-4ºS)+Sept-Mar(160ºE-140ºW, 4ºN-8ºS) Meridional Wind MW Jul-Feb (170ºE-90ºW, 0º-15ºS) - Jul-Feb (170ºE-90ºW, 0-15ºN) Indonesian Precipitation IP May-Dec (100ºE-150ºE, 10ºS-10ºN) Pacific Island Precipitation PIP Jun-Dec (160ºE-150ºW, 8ºN-8ºS) Coastal South American Air Temperature CSALT Jun-Mar (83ºW-60ºW, 30ºS-20ºN) Pacific Island Air Temperature PILT Apr-Oct (160ºE-140ºW, 0º-30ºS)

17. Weather during Pushkin’s duel Jan 27 (Feb 8), 1837 Alexander Pushkin Natalie Pushkina (nee Goncharova) Georges D’Anthes

18. Pushkin’s second: K. Danzas Danzas about the duel (4:30pm): “Despite clear weather, a strong wind was blowing. It was about -15.” Kamer-furier’s journal (Tsar’s appointment book): “There was -2 in the morning” Karamzina in her letter to her son (10 am): “Bright sun is shining, it is -3.” Conclusion of Pushkin’s scholars: It was a nice day in the morning, but temperature dropped by the time of the duel

19. St.Petersburg’s meteorological station

20. Wind Chill Factor! x

21. One word: INTERCOMPARISON