Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA...
Transcript of Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA...
![Page 1: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/1.jpg)
Assimilation of EOS Aura ozonedata at the Global Modeling and
Assimilation Office
Kris Wargan, I. Stajner, L.-P. Chang,H. Hayashi, S. Pawson, L. Froidevaux,
N. Livesey, and P. K. Bhartia
![Page 2: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/2.jpg)
Topics
● Assimilating ozone data at GMAO
● Some validation
● Springtime Antarctic ozone loss in 2005
● Defining the tropopause
![Page 3: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/3.jpg)
Assimilation of Aura ozone data into NASA’s GEOS-4
● DATA● The Microwave Limb Sounder (MLS): ozone profiles:
● 20 levels 216 – 0.14 hPa● ~ 3,500 profiles a day, near global coverage
● Ozone Monitoring Instrument (OMI): US retrieved ozone totalcolumn
● Reflectivity < 15%● Data input and analysis output every 3 hours
● MODEL● transport within GEOS-4 general circulation model constrained
by meteorological analyses● parameterizations for stratospheric photochemistry and
heterogeneous ozone loss● a parameterization of the tropospheric chemistry (for year 1998).
●TIME PERIOD: January 2005 to March 2006
![Page 4: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/4.jpg)
2005
2006
30 hPa 70 hPa
A quick glanceFebruary mean ozone in 2005 vs. 2006
Sodankyla67.4N 26.6E
[ ppmv ] [ mPa ]
![Page 5: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/5.jpg)
Belgrano 77.85S 34.55W
Hohen-peissen-berg47.8N 11E
Legio-nowo52.4N 21E
Sodankyla67.4N 26.6E
10
100
50
30
1000
500
300
Pre
ssur
e [ h
Pa
]
10
100
50
30
1000
500
300
Pre
ssur
e [ h
Pa
]Validation against sonde measurements
2005 mean ozone [ mPa ] fromradiosondes and assimilation
Mean difference betweenanalysis and sondes within10% above 300 hPa
RMS difference, sonde minusanalysis.
Up to 50% in the uppertroposphere,
● Within 40% above 100 hPaat Belgrano
● within 20% above 100 hPaat other locations
![Page 6: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/6.jpg)
Validation against measurements from Mozaic
L.A. to MunichAug 31st 2005
To Delhi March 21st 2005
MozaicAssimilation
Aircraft ozone measurements● Frequency approx. every 10 seconds● Pressure at cruising altitude ~220 hPa
●No obvious systematic bias●Small features often not resolved due to limited temporal resolution (analysis output every 3h)
Comparisons with two sample flights
![Page 7: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/7.jpg)
Antarctic Spring, ozone depletion
Our previous work with data from solaroccultation instruments (POAM 3, ILAS)demonstrated considerable positive impacts ofassimilating even a small number (e.g. 15 daily)of high vertical resolution profiles in thesouthern polar region
![Page 8: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/8.jpg)
Evolution of the ozone field at 70 hPa
A slow descent withinthe polar vortex leads toaccumulation of ozone inthe lower stratosphere
![Page 9: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/9.jpg)
Evolution of the ozone field at 70 hPa
Ozone depletion due toactivated chlorine andbromine compoundsbegins in the sunlitregion near the vortexedge
![Page 10: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/10.jpg)
Evolution of the ozone field at 70 hPa
Almost complete ozoneloss within the vortex
![Page 11: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/11.jpg)
Evolution of the ozone field at 70 hPa
Weakening anddissipation of the polarvortex allows mixing ofthe air masses.
![Page 12: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/12.jpg)
South Pole ozone sonde
Sep 20th Oct 1st
Dec 17th
Assimilation
Transport and chemistry (no ozone data, run initialized on Jan 2nd 2005)
Antarctic Spring. Correcting a systematic model bias
Excessive loss, 30 – 20 hPa
Insufficient loss in the lowerstratosphere
![Page 13: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/13.jpg)
Defining the tropopause
Different definitions of tropopause ● Temperature lapse rate (WMO)● Dynamical● Chemical
![Page 14: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/14.jpg)
> 51 hPaOzone= 0.1 ppmvOzone fromabove
< 500 hPaOzone = 0.1 ppmvOzone frombelow
> 51 hPaLower of: |PV|=3.5 PVUor θ = 380 K
Dynamical
550 to
75 hPa
Lapse rate < 2K/km anddoes not exceed 2K/kmfor 2 km above
WMO(algorithm byReichler et al2003)
Pressuresearch range
CriterionTropopausedefinition
![Page 15: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/15.jpg)
Comparing the different tropopauses
● In terms of distance ( [ km ], [ hPa ] )● In terms of mutual correlations● In terms of tracer (ozone) content
![Page 16: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/16.jpg)
WMODynamicalOzone from belowOzone from above
Ozone tropopauselower than WMOby 0.7 to 1 km innorthern midlatitudes
In terms of distance
![Page 17: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/17.jpg)
200
400
200
400
200 400 200 400
In terms of correlations between tropopausesFebruary 15th 2005
● Ozone tropopause seems better correlated with thedynamical one than with the thermal one
● At most locations the thermal tropopause lies abovethe ozone tropopause
Near-discontinuityof thermal
tropopause
![Page 18: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/18.jpg)
%
Percentage of ozone column below WMO tropopausethat lies above ozone tropopause at 00Z15FEB2005
Wind magnitude at 200hPa at 1:30Z15FEB2005
In terms of ozone content in between
![Page 19: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/19.jpg)
● Bethan et al 1996: ozonedefined tropopause lowerthan WMO tropopause byabout 1 km. When WMOtropopause indefinite, 27%of the ozone below WMOtropopause lies aboveozone tropopause.Sondes from fourEuropean stations 51°N-79°N.
In terms of ozone content in between
![Page 20: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/20.jpg)
~ 61,132 pointsFeb 15th – March 15th 20050 – 20E, 50N – 80N
Distribution obtained from the analysisreproduces some of the features
● Thermal tropopause is higher on average● There are outliers (70 – 80%)
Percentage of ozonecolumn below WMOtropopause that liesabove ozonetropopause
![Page 21: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/21.jpg)
60N – 90N 40N – 60N
Distributions obtained using all gridpoints in latitude bands
Percentage of ozone column below WMO tropopause thatlies above ozone tropopause Feb 15th – March 15th 2005
![Page 22: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/22.jpg)
20N – 40N 20S – 20N
Percentage of ozone column below WMO tropopause thatlies above ozone tropopause Feb 15th – March 15th 2005
At high altitudes,air betweenthose surfacescontainsrelatively smallportion oftroposphericozone
Thermal tropopause can be found ateither ‘top’ or ‘bottom’ of the jet.Parts of the ozone tropopause lieabove the WMO one
![Page 23: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/23.jpg)
Summary
● Retrieved ozone data from OMI and MLS (onboard EOS Aura)were assimilated in a 15 month long run
● Mean agreement with sonde data within 10% in thestratosphere
● Significant reduction of model bias is observed during Antarcticspring 2005
− Morphology of the Antarctic ozone depletion is captured accurately
● Relationships between thermal, dynamical and ozonetropopauses are studied:
− Assimilated global ozone fields allow extension of previous studies whichrely on insitu data
− Applications to studies of stratosphere-troposphere exchange areplanned.
![Page 24: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/24.jpg)
Backup
![Page 25: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/25.jpg)
![Page 26: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/26.jpg)
![Page 27: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/27.jpg)
[ km ]
Mean February approximatedistance between the two‘ozone tropopauses’
![Page 28: Assimilation of EOS Aura ozone data at the Global Modeling ...atmosp.physics.utoronto.ca/SPARC/DA/DA Presetnations to web/Wargan.pdf · Assimilation of EOS Aura ozone data at the](https://reader030.fdocuments.in/reader030/viewer/2022040823/5e6cc8c303667953004fbe72/html5/thumbnails/28.jpg)