Y. J. ORSOLININorwegian Institute for Air Research – NILU

orsolini@nilu.no

C. RANDALLLASP, University of Colorado, Boulder, USA

G. MANNEY    NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, USA

  D. ALLEN 

  US Naval Research Laboratory, USA

Transport processes in the stratosphere, diagnosed from ENVISAT-MIPAS

observations

Operational Retrievals from ESA : NEAR REAL-TIME data•Illustrate the use of ENVISAT/MIPAS observations of ozone and water vapour•Diagnostic studies of transport processes in the stratosphere

MOTIVATION : USE of ENVISAT/MIPAS OBSERVATIONS

TWO PERIODS ARE EXAMINED•Austral spring 2002 : final warming following the famous vortex split event •(Boreal summer 2003)

•Unusual evolution occurred in the winter and spring 2002•Previously unobserved Stratospheric Sudden Warming in late SEP•Vortex Splitting in two lobes, with strong impact on Antarctic ozone hole•Small vortex recovered a pole-centered position in mid-OCT, after one lobe was absorbed in mid-latitudes

•Final break-down in early NOV, earlier than climatology (e.g. at 10 mb)•Vortex interactions involving a large near-stationary anticyclone, located south of Australia

Stratospheric Vortex in the Austral Spring 2002 : The split event

The break-down

•ECMWF operational analyses of potential vorticity, winds at very-high resolution T511 (0.1 degree) •UKMO analyses

Vortex breakup in early NOV

Tongues of polar air (coiling around the anticyclone, south of Australia) Tongues of subtropical air (coiling around the vortex)

Filaments /coherent vortices

METEOROLOGICAL DATA Potential vorticity and winds (ECMWF analyses)

FIG 1 : Wind reversal in the stratosphere in Spring 2002. The zonal-mean zonal wind at 60S are shown as monthly means for SEP to NOV. Note the rapid

decceleration by OCT and the descent of easterlies through 30 mb in NOV.

ECMWF PV in NOV 2002 (850K, near 10mb)

Vortex Tongue ”V”

SubtropicalTongue ”S”

Anticyclone

METHODOLOGY•OZONE, WATERVAPOUR and TEMPERATURE (Level-2 ”Meteo-Products”)•1 month (beginning OCT 24)•Vertical resolution ~4km•Interpolation on isentropes (e.g. 650K, or 850K)•Binning in lat / lon [10 x 30 deg], and time [3 days] (Missing Data !)

•note : Vortex air is identified as relatively moist, ozone-poor air (at 850K, or 10 mb)

Mapping of MIPAS Ozone, Water Vapour Operational Retrievals from ESA : NEAR REAL-TIME

data

MAPPING•Mapping of MIPAS observations solely.•Comparison with reverse-trajectory calculations (”RDF”-like method)•Comparison with other satellite data : inferences from solar occultation data (HALOE, SAGE, POAM)

Maps of MIPAS H2O (850K, near 10 mb)

High-resolution Maps of H2O (850K, near 10 mb) reconstruction using a domain-filling trajectory method

Maps of MIPAS O3 (850K, near 10 mb)

Lower stratospheric vortex• Vortex break-down is a TOP-DOWN process•Evidence for a longer-lived vortex at lower levels (e.g. 475K) : in PV, MIPAS O3 and H2O

OCT 24-30

NOV 7-13

NOV 14-20

475K : PV and O3 850K : PV, O3, H2O

OCT 24-30

OCT 24-30

MIPAS H2O cross sections (southern hemisphere)

EQUIVALENT LATITUDE

THETA

HEIGHT

MIPAS H2O cross sections (southern hemisphere)

THETA

HEIGHT

Proxy O3/H2O reconstruction using solar occultation measurements

•“Sparse” satellite observations from solar occultation instruments•reconstruct O3/H2O maps using an isentropic relation between “PV” and tracer [Randall et al.,2002]

•UKMO PV•Use several instruments together (well calibrated with respect to one another) •For O3 : latitude-dependent fits, but not for H2O

EQUIVALENT LATITUDE

ECMWF PV on NOV 16, 2002 (475K)

Proxy HALOE-POAM H2O (850K, near 10 mb)

GEOPHYSICAL VALIDATION OF MIPAS •1 Month of MIPAS mapped observations of O3/H2O : SH vortex breakup in spring 2002•Continuity between maps / Consistency between O3 and H2O : high-quality of MIPAS obs•Position of the vortex major remnants, vortex erosion :

MIPAS / analyses of PV / inference from solar occulation data

Article in Special Issue of J. of Atmospheric Sciences on Antarctic winter and sudden warming in 2002.Orsolini, Y. J. , C.E. Randall, G.L. Manney and D.R. Allen, An observational study of the final breakdown of the southern hemisphere stratospheric vortex in 2002, J. of the Atmospheric Sciences, Revised, Feb., 2004

Conclusions

EVENTS IN SH STRATOSPHERE DURING SPRING 2002 •Vortex breakup in early days of NOV at 10 mb (early!). •Longer-lived vortex in lower stratosphere•Synoptic evolution and vortex interactions during the break-down