Research on the high-latitude middle atmosphere

dynamics clouds and aerosol particles

trace gasesProfessor Sheila Kirkwood

and colleagues

IRF-Kiruna (68°N 21°E)

Main Recent Results :

a) Instruments and techniques

ESRAD MST RADAR

Running since July 1996

troposphere summer mesopause

DESCARTES CFC sampler

34 successful flights 1997-2000accurate calibration (ongoing)

Arvelius, Dagnesjö, Nilsson, Rosmark

Millimeter wave radiometer - running since January 2002 (O3, ClO, N2O, HNO3)

Raffalski

LIDAR

Running since February 2004

Stebel, Nikulin, Voelger

New techniques to use EISCAT radar facility - VHF and HEATING

PMSE with EISCAT VHF - turned off by HEATING

Belova,Chilson, Rietveld

Main Recent Results :

a) Published Scientific Work

Polar Mesosphere Summer Echoes (PMSE) - a well known feature of the summer high-latitude mesosphere

ESRAD52 MHZradar

Modulation of PMSE by (electron) HEATING has a very short time constant (7-14 ms) whichcan be explained if the effect is due to enhanced electron diffusion from a previously supressed

state in the presence of charged dust

Belova,Chilson, Rietveld

Planetary waves modulate PMSE (at high-latitude) - evidence that the waves are (unexpectedly) a substantial

source of temperature fluctuations at the SUMMER mesospause

Foto :Hans Nilsson

Noctilucent clouds - the number of nights when they are seen from NW Europe varies from year to year in a ~10 year cycle

05

101520253035404550

1964196819721976198019841988199219962000

year

days of NLC

0

10

20

30

40

50

60

70

19641967197019731976197919821985198819911994

year

-but contrary to previousreports, it has NO trend

The occurrence of mid-latitude noctilucent clouds correlates

with planetary wave amplitude and phase in the stratosphere - but in a way which suggests a transport effect rather than a

direct temperature effect

A correlation of stationary planetary wave phase with the

phase of the solar cycle can partly explain the 10-year NLC

cycle

Noctilucent cloud trajectories at ~82 km altitude - controlled by planetary-wave winds which

shift in phase in 5-day, 16-day and decadal cycles

Wave maximum over W.Atlantic Wave maximim over E. Canadatemperature

Polar Mesosphere Winter Echoes (PMWE) - a less well known feature of the winter high-latitude mesosphere

- at times almost as strong as PMSE

-here during a strong solar proton event

09 Nov 2000

PMWE are too strong to be explained by even very strong turbulence turbulence

observations

Theory

0.5 dB

4 dB

All 70 km100 mW/kg

PMWE occur at heights where no turbulence should be present (17 January 2003 MaCWAVE

meteorological rocket comparison)

PMWE correlate with anomalies in lidar backscatter profiles - which may indicate a role for charged aerosol

particles in PMWE as in PMSE

Main Recent Results :

c) Preliminary scientific results not yet ready for publication :

The last minimum in the 10-year cycle in noctilucent clouds (mid-latitude) was accompanied by a minimum in

PMSE (high-latitude)

Details of the PMSE minimum suggest an indirect dynamic cause

34 m

20 m

ESRAD INTERFEROMETRIC ANTENNA

1 2 3

4 5 6

100 ms

- new evidence thatinfrasonic waves strongly modulate radar echo power

Future Plans :

a) New work already initiated

PMWE with EISCAT VHF radar

Evgenia Belova

Further studies ofPMWE / PMSE using

ESRAD, EISCAT,Lidar (Alomar, U. Bonn)

Magic ?, Odin ?, Envisat ?

Planetary wave studies with ODINplus meteorological databases (UKMO)

In relation to noctilucent clouds /PMSE

And the middle-atmosphere extension of the NAO/AO

New work on troposphere / lower stratosphere processes using radar and lidar including new cooperation with the nearby Finnish GAW station (Pallas)

Future Plans :

a) Ideas dependent on future funding

Mobileradar ?

Swedish - Finnish AntarcticStations Wasa / Aboa

Mobile MSTRadar ?

FMI/Univ. HelsinkiAerosol instruments

Mini-MAX DOAS ?

Organisational Aspects :

FORSKNINGSSTRATEGIER 2005+Institutet för rymdfysik

IRF ska bedriva grundläggande forskning och medverka i forskarutbildning i rymdfysik, atmosfärfysik och rymdteknik samt stödja exploateringen av tillämpningsmöjligheter för att därigenom förse samhället med ny kunskap.

IRF ska dessutom: som en del i ett globalt nätverk, bedriva observatorieverksamhet i rymdfysik och atmosfärfysik samt registrera och rapportera trender av betydelse för den långsiktigautvecklingen av jordens närmiljö som bas för vetenskapliga och politiska beslut.

IRF:s forskningsfronterIRF:s atmosfärfysikprogram kan ses som ett svar på senare års starka internationella intresse för atmosfär- och klimatforskning. Denna forskning har fått stor betydelse för inte minst Kiruna, där sedan tio år tillbaka en febril internationell forskningsaktivitet råder. Sveriges geografiska läge och den goda infrastruktur som finns i Kiruna har varit av avgörande betydelse för denna internationella satsning.”

IRF:s forskningsprogramNedan ges en sammanfattning av forskningsprogrammens huvudinriktningar.Atmosfärfysik• fortsatt grundforskning om globala atmosfärs- och klimatprocesser, såväl naturliga som antropogena• ökade insatser inom dataanalys, som utnyttjar globala observationer tillsammans med egna lokala.

Extracts from our institutes strategy document -----

IRF Atmosfärfysikprogram

1101 koordinering

1104 mellanatmos-färens dynamik

1105 PMSE medEISCAT

1106 Aerosoler imellanatmosfären

1107 Spårgaser imellanatmosfären

1108 metod-utveckling avsvensk jonosondering

Sheila 40%Alla

Evgenia 95%Jonas

Sheila 5%Evgenia 5%Daria 50%Arne 50%Johan 5%

PeterGrigori

UweJohan 95%

Christer 30%

mars 2004programchef

Sheila Kirkwood