My thoughtsin the latest

Gore (2006)“An inconvenient truth: The planetary emergency of global warming and what we can do about it”

薄い大気： ( 鉛直 ) / ( 水平 ) ～ 10km/10000km = 0.001

The atmosphere is not well mixed All atmospheric constituents

with finite life times are transported from their source regions to sink regions

Transport in large scales is done by coherent motions associated with lots of meteorological phenomena

Vertical stratification due to gravity causes anisotropic transport

Chemical reactions and phase transitions are done in molecular scales

Turbulent mixing is important to fill the scale gap

過去６５０ , ０００年では ?

IPCC (2007; Fig. 6.3)

～気温

～雪氷

[x1000 year]

Correlations in time-series do not tell causality Both detection (observational

facts) and attribution (scientific understandings) are important

Time variations take place in an open Earth system (F-D sys.)

Time variation consists of autonomous internal variations and response variations to external forcings

There are multiple time scales of periodic forcings from diurnal cycle, …. to Milanković

Time scale is basically determined by momentum, thermal, or chemical inertia of the corresponding subsystem

Return to the agenda

17th Session of WCRP/SPARC SSG26-30 October 2009Kyoto Univ., Japan

3.33.3Stratosphere-Stratosphere-Troposphere Troposphere Dynamical Dynamical CouplingCoupling

Shigeo Yoden Shigeo Yoden

Kyoto Univ.

Grants-in-Aid for Scientific Research (A)

“Assessment of the Stratospheric Effects on Climate Change

and Elucidation of the Dynamical Role”

PI : Shigeo YODEN (Kyoto Univ.)

Co-I :

T. Hirooka, T. Horinouchi,

K. Ishioka, K. Kodera,

H. Mukougawa, Y. Naito,

K. Shibata, and M. Taguchi

1. A Japanese research project for FY2008 - 2011

Main dynamical processes in the general circulation of the atmosphere, which we are interested in this project

- 9 -

Research group

internal variation vs. response to external forcingstratospheric sudden warming (SSW) events solar cycle modulation, intermittent volcanic eruptions

multiple time scaleswinter polar region

SSW ~ daysNAM/SAM, PJO ~ monthsseasonal marchinterannual variations, trends

downward propagation of information

wave propagations“top” boundary condition, reflection wave-mean flow interaction

mean meridional circulation

amplification mechanismresonance of wave ? stochastic resonance ????

2. Some key points on S-T dynamical coupling

Baldwin and Dunkerton (2001)

We performed parameter sweep experiments to study the sensitivity and use a large sample method for significance test

Influence of solar cycle modulations in W or E phase of QBO difference of [T ] in (K) between Solar Max run and Solar Min run

Combined effects of QBO and 11-year solar cycle on the winter hemisphere in a stratosphere-troposphere coupled system

>95%

Warm

Cold

>95% >80%

>80%

significance test

K. Ito, Y. Naito, and S. Yoden (2009, GRL )

Frequency distribution of time-mean zonal-mean temperatureSolar Max runs and Solar Min runs in W or E phase of QBO

[T ] changes in the winter pole caused by solar heating anomaly around the stratopause are consistent with Labitzke relationshipHowever, the difference is much smaller than that caused by the QBO

with heavy overlapping of the PDFs

T50 EQ

2007 2008 20092006

T10 NP0 C

-80

-40

-61 C

-73

-67

<20S-20N>

<80N-90N>

W E W

Impact of the stratospheric sudden warming in the tropical troposphere

2009 January major warming has a huge impact on the tropical stratosphere

K. Kodera, N. Eguchi, and T. Ichimaru

(III) 24-30 Jan(II) 16-22 Jan

Zonaly averaged ω

(I) 8-14 Jan

40S EQ 40N

30

100

1000

300

40S EQ 40N 40S EQ 40N

U, EPF

　　　 40S 20S EQ 20N 40N

Composite O3 (%) evolution during SSW (SCO < -3.0)

10+3

10+2

10+1

10+0

-40 0 +40

30 events in 5-member simulation (MRI-CCM) for 1980-2004

-40 0 +40

P

T (days)

-40 0 +40 -40 0 +40 -40 0 +40

Impacts of SSW and VI on O3K. SHibata

VI O3 (%) evolution in NH

-40 0 +40 -40 0 +40 -40 0 +40-40 0 +40 -40 0 +40

　　　 40S 20S EQ 20N 40N

Composite O3 (%) evolution during VI (SCO > +2.5)

36 events in 5-member simulation (MRI-CCM) for 1980-2004

10+3

10+2

10+1

10+0

P

T (days)

(1) ENSO influence in WACCM We compare 2 perpetual JAN

runs, each 3650 days long: one for La Nina and the other for El Nino SST conditions.

We make a diagnostic analysis based on TEM equations.

Taguchi (2009, JAS, accepted)

Influence of ENSO to Tropical/Subtropical Wave Driving (WD) in WACCM Masakazu Taguchi (Aichi Univ. of Education)

Mean changes: El Nino - La Nina

[T] [U]

BDC EPFIn tropical lower stratos., cooling, increased poleward upward/ flow, and increased WD occur for El Nino.

Increased WD by stationary waves including eq. Rossby waves

－

－－

A numerical study of upward-propagating gravity waves in two different MJO phases

Horinouchi (2008, GRL )

High frequency components of w’

　　　 Inactive phase of MJO 　　　　　　　 Active phase of MJO

We study influence of stratospheric NAM variations to the forecast skill of tropospheric NAM index by using 5-winter (2001/02-2005/06; DJF) archive of the JMA 1-month ensemble forecast dataset.

Prediction skill of ensemble-mean NAM index in the upper troposphere is significantly improved for 5- to 13-day forecast when negatively large NAM indices are observed (weak westerly winds) around 30hPa at the initial time in comparison with stratospheric positive NAM events.

Influence of Stratospheric Circulation on the Predictability of the tropospheric NAM H. Mukougawa, T. Hirooka and Y. Kuroda (2009, GRL )

significance testheavy shade > 99.9 %shallow shade > 99 %

lead time (days)

Mean Square Error (MSE) of 250-hPa NAM index

Classified by 30-hPa NAM　　　　　　 NAM < -1 NAM >+1 -1<NAM<+1

Predictability limits of stratospheric circulation

T.Hirooka (Kyushu Univ.)On the basis of RMSE and AC analyses of JMA one-month forecasts in the stratosphere, the predictability of stratospheric circulations in the NH winter during 2001-2006 is investigated.

Pre

dict

abili

ty (

days

)

AC

Pre

dict

abili

ty (

days

) Small amp Small amp

Large amp Small amp

RMSE

and more ……

For your information

the XXV IUGG General Assembly in 2011Earth on the Edge: Science for a Sustainable Planet

28 June - 7 July 2011Melbourne, Australia

Symposia proposed or co-sponsored by ICMA UNION Symposium (IAGA, IAMAS, SCOSTEP, … )

“Climate and Weather of the Sun-Earth System – CAWSES-II”A. Rodger (British Antarctic Survey), D. Marsh (NCAR), …

ICMA sponsored Symposia

“Middle Atmosphere Science”S. Yoden (Kyoto Univ.), B. Funke (CSIC), D. Murphy (AAD), T. Horinouchi (Hokkaido

Univ.)

“The Impact of Solar Variability on Earth”U. Langematz (Free Univ. Berllin), W. Schmutz (PMOD/WRC), L. Hood (Univ. Arizona),

V. Fomichev (York Univ.), J.D. Haigh (Imperial College), T. Woods (Univ. of Colorado)

“Chemistry-Climate Interactions”L. Pan (NCAR), G. Bodeker (New Zealand), J. Burrows (Univ. Bremen),

Y. Kondo (Univ. Tokyo), E. Rozanov (PMOD/WRC)

“Stratosphere-Troposphere-Ocean Coupling in Weather and Climate”

 E. Manzini (INGV-CMCC), J. Alexander (NWRA)

ICMA-SPARC joint symposium

“Stratospheric Processes and Their Role in Climate Focussed on the Southern Hemisphere”

G. Bodeker (New Zealand), K. Pienaar (Potchefstroom Univ.)

IAMAS-IAGA joint symposium

 “External Forcing on the Middle Atmosphere and Lower Ionosphere” 

A. Krivolutsky (Central Aerological Observatory), J. Lastovichka (Inst. of Atmos. Phys.)

 

Thanks !