Shigeo Yoden Department of Geophysics Kyoto University Japan ESF-JSPS Frontier Science Conference Series for Young Researchers « Climate Change » Nynäshamn Sweden 24-29 June 2006 Session 5: Future climate change The Use of Numerical Models to Understand Climate Variability and Change
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Shigeo Yoden Department of Geophysics Kyoto University Japan ESF-JSPS Frontier Science Conference Series for Young Researchers « Climate Change » Nynäshamn.
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Shigeo YodenDepartment of Geophysics
Kyoto UniversityJapan
ESF-JSPS Frontier Science Conference Series for Young Researchers« Climate Change »Nynäshamn Sweden 24-29 June 2006Session 5: Future climate change
The Use of Numerical Models to Understand Climate Variability
and Change
Shigeo YodenDepartment of Geophysics
Kyoto UniversityJapan
ESF-JSPS Frontier Science Conference Series for Young Researchers« Climate Change »Nynäshamn Sweden 24-29 June 2006Session 5: Future climate change
Internal Interannual Variabilityand Detectability of Climate Change
of the Stratosphere-TroposphereCoupled System
1. General Introduction
1.1 Climate change Global warming
warming in the tropospherecooling in the stratosphere
why cooling in the
stratosphere ?
effects of volcanic eruption
IPCC the 3rd report (2001)
Lower Stratosphere
Lower Troposphere
Global average temperature anomaly
1.2 Interannual variations of the S-T coupled system possible causes (Yoden et al. 2002; JMSJ Special Issue)
responses to external forcingssun, volcano, human being, ... (ENSO, ice, biomass, ...)
A schematic illustration of the optimum situation for meteorological research
Hierarchy of numerical models Hoskins (1983; Quart.J.Roy.Meteor.Soc.)
“Dynamical processes in the atmosphere and the use of models”
Three classes of the atmospheric modelssimple Low-Order Model (LOM)
O(100~101) variables for conceptual description
Lorenz(1960,1963)
medium Mechanistic Circulation Model (MCM) O(104 ~ 105) variables for understanding mechanisms
Boville(1986)
complex General Circulation Model (GCM)O(104 ~ 107) variables for quantitative arguments
Phillips(1956), Smagorinsky et al.(1965), ...
Balanced attack with these models is important !
JMA (1996)
2. The Use of Numerical Models to Understand Internal Variability and Climate Changein the Stratosphere-TroposphereCoupled System
2.0 Numerical experiments on the S-T interannual variations in our group in Kyoto for these two decadesLOM
Yoden (1987a,b,c) stratospheric sudden warmings (SSWs)Yoden and Holton (1988) quasi-biennial oscillation (QBO)Yoden (1990) seasonal march in NH and SH
MCMTaguchi, Yamaga and Yoden (2001) SSWs in S-T coupled systemTaguchi and Yoden (2002a,b,c) internal S-T coupled variationsNaito, Taguchi and Yoden (2003) QBO effects on coupled variationsNishizawa and Yoden (2005) spurious trends due to short datasetNaito and Yoden (2006) QBO effects on coupled variations
GCMYoden, Naito and Pawson (1996) SSWs in Berlin TSM GCMYoden, Yamaga, Pawson and Langematz (1999) a new Berlin GCMNishizawa, Nozawa and Yoden (2006) precip. in CCSR-NIES CGCM
2.1 Occurrence of stratospheric sudden warmings internal variability
polar vortex variation due to internal dynamicsstatistics ?characterization of the unprecedented year 2002 in the SH
ENSO
StratosphericSudden
Warmings
StratosphericSudden
Warmings
2002
Major stratospheric warming in the SH in 2002Hio and Yoden (2005, JAS Special issue )
Dynamical aspects of the ozone hole split in 2002association with the major stratospheric sudden warming Baldwin et al. (2003)
http://jwocky.gsfc.nasa.gov/
Hio and Yoden (2005, JAS Special issue ) “Interannual variations of the seasonal march in the Southern H
emisphere stratosphere for 1979-2002 and characterization of the unprecedented year 2002”
Scatter diagram between upward EP flux (45-75S, 100hPa, Aug.16-Sep.30) and zonal-mean zonal wind (45S, 20hPa, Oct.1-15)
an extreme event with high-correlation - 0.73 - 0.86 02
Taguchi and Yoden (2002, JAS ) “Millennium integrations of a coupled S-T model”
SH-like NH-like3-dimensional Mechanistic Circulation Model
Monthly mean T (90N, 2.6 hPa)
reliable PDFs (mean, std., skewness, ....)
SH springnon-Gaussian long tail for extreme events
Taguchi and Yoden (2002b)Frequency distribution of the monthly mean temperatureat the pole, 2.6 hPa for 1000-year integrations
Frequency distribution [%]
xσ -3 -2 -1 Mean +1 +2 +3 +4 +5 .
-U45S,20hPa 4.2 4.2 58.3 20.8 8.3 0.0 4.2 0.0 0.0
Gaussian 2.1 13.6 34.1 34.1 13.6 2.1 0.1 3x10-3 -
T&Y(Feb.) 0.3 8.7 47.7 32.8 7.0 1.8 1.1 0.2 0.2
2.2 Influence of the QBO on the global circulation internal variability vs. response to “external” forcings
polar vortex variation due to internal dynamicsQBO in the tropics change at the side boundarymodulation of the polar vortex due to QBO ?
ENSO
StratosphericSudden
WarmingsInfluence of the QBOpropagation route of planetary waves
Gray et al. (2001; Baldwin et al., 2001, Plate 1)
Observations
Wallace (1973; AHL, 1987, Fig.8.2)latitude-height section of amplitude and phase of the zonal