# Presentation: 729144

## 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

## 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.  

## 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
**SST****bucket**** = SST****true ****+ ******** ****(AT - SST****true****)**
- Engine intake SST has constant offset
**SST****engine intake**** = SST****true**** + ******

- New Bayesian model for joint probability density function of  and 

- 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.

## Estimates of  (which gives the error due to heat loss in the bucket SST) remain fairly constant at ~15% over the period 1975-1994.
Estimates of  (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  changes sign suggesting the engine intake SST is biased cold.
This would mean that both methods are biased cold in this period.

- Estimates of  (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  changes sign suggesting the engine intake SST is biased cold.
- This would mean that both methods are biased cold in this period.

- Model for Bias in ship *in situ* SST (cont.) [Kent and Kaplan, *J. Climate*, in press]

## 20th 

**Difference between 2 OIs:**
**     ****ICOADS SST – GHCN air temperature**
**Correlation coeff               RMS diff**

**20****th**** **
**Century**
**19****th**** **
**century**

## I-COADS

- analyses

-   GHCN
-  analysis

- Ocean
- model
- response
- to the
- wind
- analysis

## William Quinn’s criteria for El Niño events

## William Quinn’s references for El Niño events chronologies

## Slide 9

## Slide 10

## Historical chronologies vs instrumental and proxy ENSO indices

## New instrumental indices of 

- 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)

- New instrumental indices of
- El Nino – Southern Oscillation (ENSO)

## Slide 13

## Slide 14

## Slide 15

## Slide 16

## Weather during Pushkin’s duel Jan 27 (Feb 8), 1837

**   ****Alexander Pushkin      Natalie Pushkina (nee Goncharova)            Georges D’Anthes**

## 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****   **

## St.Petersburg’s meteorological station

## Wind Chill Factor!

**x**

## One word:
INTERCOMPARISON

**INTERCOMPARISON**