Climatology and Interannual Variability of Dynamical Variables - - PowerPoint PPT Presentation

CHAPTER 3 Climatology and Interannual Variability

• f Dynamical Variables

Chapter Leads: Craig Long (NOAA, USA) Masatomo Fujiwara (Hokkaido University, Japan) Co-authors: Sean Davis (NOAA, USA) Daniel Mitchell (University of Oxford, UK) Corwin Wright (University of Bath, UK)

S-RIP Workshop ~ October 19-21, 2016 ~ Victoria, BC

Table of Contents

• SUMMARY

2

• 3.1. INTRODUCTION

3

• 3.2. REANALYSES GLOBAL TEMPERATURE ANOMALY VARIABILITY WITH TIME

5

• 3.3. REANALYSIS ENSEMBLE MEAN (REM)

6

• 3.3.1. Methodology

6

• 3.3.2. Climatology of the REM

6

• 3.3.3. Agreement Among the REM Members

9

• 3.4. INTERCOMPARISONS OF THE REANALYSES

12

• 3.4.1. Temperature

12

• 3.4.2. Zonal wind

14

• 3.5. AMPLITUDE OF POLAR ANNUAL TEMPERATURE CYCLE

17

• 3.6. COMPARISONS WITH INDEPENDENT OBSERVATIONS

17

• 3.6.1. MLS and HIRDLS Temperatures

17

• 3.6.2. Atmospheric Layer Temperature Anomalies

17

• 3.6.3. Ozonesonde Temperatures

18

• 3.6.4. Long-duration Balloon Observationss

20

• 3.6.5. Rocketsonde Observations

21

• 3.7. EFFECTS OF VOLCANIC ERUPTIONS ON REANALYSIS TEMPERATURES AND WINDS

25

• 3.8. SUMMARY AND CONCLUSIONS

23

• REFERENCES

29

• Appendix A. LIST OF ACRONYMS

27

Schedule

• Under internal review now
• External review soon after
• Paper?

Key Findings

• TOVS vs ATOVS periods have different temp and wind characteristics in

middle and upper stratosphere.

• CFSR has a warm bias and JRA-55 has cold bias in upper stratosphere

compared to MERRA and ERA-I.

• Comparisons with MLS and HIRDLS temperatures produce similar bais

results.

• CFSR stream jumps interfere with any trend analysis and introduces too

much noise to the REM.

• ERA-I has smaller annual temperature cycle in SH polar latitudes during

the TOVS period above 10 hPa.

• All reanalyses QBO winds correlate well with Singapore winds, but are

weaker

– Improvement in ATOVS period

• CFSR, MERRA, ERA-I, JRA-55 replicate NOAA TLS CDR well
• MERRA, ERA-I, JRA-55 replicate NOAA SSU1&2 CDR well

– Beginning years and ending years differ from CDR

Selection of Chapter Figures

• Inclusion of MERRA-2 comparisons
• QBO comparisons
• Added HIRDLS Temp comparisons
• Layer mean comparisons with NOAA SSU+AMSU CDRs

Global Temperature Anomaly

Global Temperature Anomaly

REM = MERRA & ERA-I & JRA-55

Temperature Variance of 3 Members

60N-90N 10S-10N 60S-90S

U Wind Variance of 3 Members

60N-90N 10S-10N 60S-90S

m/s

a) b) c) d) e)

60S-90S Temperature Diff from REM

f) g) h)

60S-90S Temperature Diff from REM

60N-90N Temperature Diff from REM

60N-90N Temperature Diff from REM

Equatorial U Wind Diff from REM

m/s

Equatorial U Wind Diff from REM

m/s

Figure 21. Reanalysis Ensemble Mean (REM) zonal wind departures (m/s) from the long term REM mean for each month between 10°S and 10° N. The REM is the average of MERRA, ERA-I, and JRA55 zonal winds.

REM U Wind Anomalies at Equator

Comparisons of REM with Singapore U winds Correlation Slope

Singapore U Wind Reanalysis U Wind

REM winds are weaker than Singapore

1980-2014 1980-1998 1999-2014

Comparisons of Reanalyses with Singapore U winds Correlation Slope

SH Max T Month – Min T Month

NH Max T Month – MinT Month

2004-2014 MLS Comparisons : 60N-80N

MLS Comparisons : 60N-80N 2004-2014

HIRDLS Comparisons : 60N-80N 2005-2008

SSU MSU 3 2 1 4 9

SSU & MSU 1978-2005 AMSU-A 1998-Present

TLS - Lower Stratosphere

Clim = 1981-2010

CFSR MERRA & MERRA-2 ERA-I JRA-55

SSU 1 – Middle Stratosphere

CFSR ERA-I MERRA & MERRA-2 JRA-55

SSU 2 - Upper Stratosphere

CFSR ERA-I MERRA & MERRA-2 JRA-55

Any Comments or Suggestions? Did I miss anything?