project id: 10577 chemistry climate change - earth...
TRANSCRIPT
Influence of the tropical intra-seasonal variation on wintertime stratospheric ozone over East Asia and Northern Hemisphere stratospheric polar vortex
Chuanxi Liu1, Yuli Zhang1, Yi Liu1, Viktoria Sofieva2, and Erkki Kyrölä2 1 Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing
2Finnish Meteorological Institute, Helsinki, Finland
Project ID: 10577 Chemistry Climate Change
Motivation A multi-timescale investigation of the chemistry and climate in middle atmosphere A focus on the Upper Troposphere and Lower Stratosphere (UTLS)
Motivation A multi-timescale investigation of the chemistry and climate in middle atmosphere A focus on the Upper Troposphere and Lower Stratosphere (UTLS)
Sudden Warming
Stratospheric O3 Intrusion
(Liu et al., 2013)
O3 Trend over Beijing
(Wang et al., 2012)
EOFs of the GOME tropospheric ozone over EAsia (Liu et al., in press)
Polar Vortex Disturbances
Dragon II
Madden-Julian Oscillation
Madden-Julian Oscillation (a.k.a. Intraseasonal, 30–60 day oscillation)
• Dominant component of the intraseasonal (30–90 day) variability in the tropical atmosphere
• Slow eastward propagation (~5 m/s) of the well-organized convections
• Associated with large-scale anomalies of
Rossby/Kelvin waves, precipitation, and atmospheric compositions
• Important for extended-term weather forecast
Indian Pacific
Background
Madden and Julian [1972]
Precipitation anomalies associated with MJO
Background
Blue: positive anomalies (enhanced convections) Red: negative anomalies (suppressed convections)
Background Definition of the 8 MJO phases
Eastward propagation
Based on the locations of the enhanced convection (i.e., postive precipitation anomalies)
Strongest around phase 3
Much weaker in phases 7-8 and 1
Background MJO’s influence on atmospheric dynamics and compositions
Transport the air from maritime boundary layer into the UT, and sometimes produce extremely low ozone events in the UT. Wong and Dessler [2007]; Ziemke et al. [2007]; Cooper et al. [2013]
• Tropics and Sub-Tropics
Gill [1980]
Monsoon systems, ITCZ, tropical cyclone, ENSO
Tian et al. [2007]; Li et al. [2012; 2013]
Anticyclones Cyclones
MJO’s convective heating in Tropics
Lower Troposphere
Upper Troposphere
Elevated Tropopause Depressed Tropopause
Rui and Wang [1990]
Negative column ozone anomaly Positive column ozone anomaly
Background MJO’s influence on atmospheric dynamics and compositions
• Tropics and Sub-Tropics
• Extra-Tropics (via Rossby-wave train or teleconnection) MJO’s influence on atmospheric dynamics and compositions
Background
Interacts with storm-track, blocking, polar vortex, NAO/AO
Trenberth et al. [1998]
• How can MJO influence stratospheric O3 over East Asia ?
• How well do ESA’s satellites characterize the MJO
signal in stratospheric O3 over East Asia ?
• How well does NCAR’s chemistry transport model reproduce the MJO signal in stratospheric O3 over East Asia ?
Part I
• ERA-Interim reanalysis
• Satellite measurements from MIPAS, GOMOS, SCIAMACHY
• Model simulation from SD-WACCM
Data and Methods
• To isolate the intra-seasonal variation associated with MJO, a band-pass filter (20–100-day) has been applied to the daily anomaly.
Data and Methods (Continued)
IV/V
II/III
VI/VII
VIII/I
MJO-related O3 anomalies over East Asia
Negative O3 anomalies are over East Asia, when the MJO moves from Indian Ocean towards western Pacific (i.e., MJO phases 4~6).
MJO-related precipitation anomalies in DJF
MJO-related column ozone anomalies between 200 and 20 hPa
MJO-related tropopause anomalies
The MJO modulates stratospheric O3 via its influences on tropopause height.
P4~P5
P2~P3
P6~P7
P8~P1
MJO-related tropopause pressure anomalies
Latitude-Altitude distribution of O3
“barrier” for the latitudinal mixing
North
Alt
MJO-related variation in subtropical jet
The MJO can modulate UTLS O3 in subtropics via its influence on subtropical jet.
Rossby waves shift Jet
North
90oE
200-hPa U
• Different features over the Tibetan Plateau and East China
• Difference between ERA-Interim and SD-WACCM
Vertical profile of the MJO-related O3 anomalies
ERA-Interim MIPAS SCIAMACHY GOMOS
Tibetan Plateau
East China
Zhang et al., 2015 (in press)
All data highlight the different vertical structures (Dr. Yuli Zhang’s poster) !
Satellite Measurements
Units: DU/km
The different results in GOMOS measurements can be attributed to sampling issues and retrieval bias (see Dr. Zhang’s poster for details).
ERA-Interim SD-WACCM
Tibetan Plateau
East China
Model Simulations
Liu et al., 2015 (in press)
The different vertical structures are also reproduced by the chemistry-transport model .
ERA-Interim SD-WACCM
Model bias
Amplitude of MJO-related O3 signal in model is larger than that in ERA-Interim.
O3 Temperature
The temperature in the model is highly consistent with ERA-Interim. But, the calculated O3 concentration is much higher in the UTLS.
• The MJO signal in the stratospheric ozone over East Asia has been examined using ERA-Interim, satellite measurements, and chemistry transport model.
• All datasets have highlighted the different vertical structures of MJO-related ozone anomalies over the Tibetan Plateau and East China.
• We have discerned a positive model bias in the amplitude of MJO-related ozone anomalies in the UTLS region.
Summary of Part I
• Relationship between tropical MJO and NH stratospheric polar vortex, especially the major stratospheric sudden warming (SSW) events
Part II
They are different, in terms of tropospheric precursors, stratospheric structures, and downward weather influences.
e.g., O’Neill [2003]; Charlton and Polvani [2007]; Matthewman et al. [2009]; Martius et al. [2009]; Castanheira and Barriopedro [2010]; Cohen and Jones [2012]; Hitchcock et al. [2013]; Mitchell et al. [2013]; Seviour et al. [2013]
vortex-displacement (VD) SSWs vortex-split (VS) SSWs
Two types of major SSWs
Background
VD SSW central dates
VS SSW central dates
29 Feb 1980 02 Jan 1985 04 Dec 1981 08 Dec 1987 24 Feb 1984 14 Mar 1988 23 Jan 1987 22 Feb 1989 15 Dec 1998 26 Feb 1999 20 Mar 2000 18 Jan 2003 16 Dec 2000 24 Jan 2009 02 Jan 2002 09 Feb 2010 07 Jan 2004 21 Jan 2006 24 Feb 2007 22 Feb 2008
12 VD events 8 VS events
Major SSW events (1980-2010)
Evolution of OLR anomalies before the central dates
Vortex-displacement Vortex-split OLR is averaged for every 6 days. No band-pass filter has been used !
Stationary OLR anomaly Synoptic scales can also be important !
Vortex-displacement events
Eastward propagating OLR anomaly MJO dominates the OLR variability !
Vortex-split events
Liu et al., 2014
• Influence of Quasi-Biennial Oscillation (QBO) on the connection between MJO and SSW
Interannual variation in the MJO-SSW connection
QBO dependence of different types of SSWs
VD SSW central dates
QBO index
29 Feb 1980 –1.22 04 Dec 1981 –0.26 24 Feb 1984 –0.24 23 Jan 1987 –0.05 15 Dec 1998 –1.01 20 Mar 2000 1.04 16 Dec 2000 –0.14 02 Jan 2002 –0.79 07 Jan 2004 –0.98 21 Jan 2006 –1.75 24 Feb 2007 0.99 22 Feb 2008 –1.77
VS SSW central dates
QBO index
02 Jan 1985 –1.14 08 Dec 1987 0.50 14 Mar 1988 0.44 22 Feb 1989 0.32 26 Feb 1999 –0.42 18 Jan 2003 0.71 24 Jan 2009 1.09 09 Feb 2010 0.04
10 out of 12 VD-SSWs during eQBO 6 out of 8 VS-SSWs during wQBO
Similar results based on 50-hPa and 30-hPa QBO index.
Zonal-mean U anomalies for different types of SSWs
Vortex-Displacement Vortex-split
eQBO wQBO
Zonal-mean U anomalies for different QBO phases
Liu et al., 2014
Influence of QBO on MJO-related planetary waves
Vortex-displacement Vortex-split
25-day after MJO phase 3 during wQBO
25-day after MJO phase 3 during eQBO
Liu et al., 2014
100-hPa EP-flux and 300-hPa Jet-stream
Northward propagation !
WN-1
patterns
Eastward propagation !
WN-2
patterns
• Connection between MJO and stratospheric dynamics in boreal winter is examined.
• Relationship between MJO and vortex-split SSW is stronger than that between MJO and vortex-displacement SSW.
• MJO-related dynamical disturbances in extratropics are modulated by stratospheric QBO.
Summary of Part II