1. Access and visualization of theTwentieth Century Reanalysis dataset
Gilbert P. Compo, Cathy Smith,
Jeffrey S. Whitaker, and
Prashant D. Sardeshmukh
Univ. of Colorado/CIRES
Climate Diagnostics Center and
NOAA Earth System Research Laboratory/PSD
Compo, Whitaker, Sardeshmukh 2006
Special thanks to N. Matsui, R. Vose, R. Allan, S. Woodruff, NCEP/EMC

2. Requires international cooperation, e.g.,
Advances and Improvements towards Surface Input Reanalysis for Climate Applications (SIRCA) 19th-21st centuries
More land and marine observations back to early 19th century, especially S. Hemisphere.
Tailoring of reanalysis products, e.g., downscaling
User requirements for, and applications of, reanalyses
Verification and Validation of reanalysis products
Higher resolution, improved methods, other surface variables (e.g., wind, T, Tropical Cyclone position)
Requires international cooperation, e.g.,
Atmospheric Circulation Reconstruction over the Earth

3. Current and future International Surface Pressure Databank station component (1670 to 2009) ftp://ftp.ncdc.noaa.gov/pub/data/ispd/add-station
Courtesy X. Yin and R. Allan

4. Reanalysis Dataset Current and Planned Access
20th Century Reanalysis Project
Data Access: Analyses and ISPD (with feedback) will be freely available from NCAR, NOAA/ESRL and NOAA/NCDC.
Spring 2009: version (complete, more data being added online)
(NOAA ESRL)
(NCAR)
Fall 2009: version (including time-varying CO2, aerosols, upgraded GFS from NCEP)
ftp://ftp.cdc.noaa.gov/Public/gcompo/ (NOAA ESRL)
Spring 2010: version
(NCAR)
(NOAA NCDC)
Coordinate with PCMDI CMIP5 distribution and validation for IPCC AR5

5. 500 hPa Geopotential Height
Northern Hemisphere Ensemble Mean Analysis and Spread 15 December UTC
SLP
15 December 1891
500 hPa GPH
Note uncertainty changes, polar regions early on. mb m
Sea Level Pressure
500 hPa Geopotential Height
Contours- ensemble mean
Shading- blue: more uncertain, white: more certain

6. 20th Century Reanalysis Project Homepage http://www. cdc. noaa

8. Monthly mean composites (beta)
Plotting page courtesy Cathy Smith
(U. of Colorado CIRES and NOAA ESRL PSD)
Daily means are also available

9. Comparison of El Nino composite of 300 hPa Geopotential Height from January to March ( ) – ( )
NCEP/NCAR Reanalysis
20th Century Reanalysis
The overall patterns are very similar.
20th Century reanalysis data appears to have stronger signals in extratropics of both hemispheres, weaker signals in Tropics.

10. Monthly mean composites on Google Earth http://www. cdc. noaa

11. Monthly mean composites on Google Earth

12. Thank you Questions? Contact : Jeffrey.S.Whitaker@noaa.gov

13. Higher resolution example of Surface Input Reanalyses for Climate Applications (SIRCA)

14. 2008 NCEP GFS at ~50km resolution September 1938 New England (movie)
T254L64 (~50 km)
Is the extraordinary upper-level trough correct?

15. 2008 NCEP GFS at ~50km resolution 21 September 1938 00 UTC
Sea Level Pressure
500 hPa geopotential height
Is the extraordinary upper-level trough correct?

16. Any Skill Forecasting the Track?
36 hour forecast verifying 21 Sept Z
Ensemble Forecast
HURDAT Track
using 56 ensemble members T254L64 (about 0.5 degree)