Research on the high- latitude middle atmosphere dynamics clouds and aerosol particles trace gases Professor 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 accurate calibration (ongoing) Arvelius, Dagnesjö, Nilsson, Rosmark

Millimeter wave radiometer - running since January 2002 (O 3, ClO, N 2 O, HNO 3 ) 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 ESRAD 52 MHZ radar

Modulation of PMSE by (electron) HEATING has a very short time constant (7-14 ms) which can 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 -but contrary to previous reports, 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.AtlanticWave maximim over E. Canada temperature

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 km 100 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 ms - new evidence that infrasonic waves strongly modulate radar echo power

Future Plans : a) New work already initiated

Further studies of PMWE / PMSE using ESRAD, EISCAT, Lidar (Alomar, U. Bonn) Magic ?, Odin ?, Envisat ?

Planetary wave studies with ODIN plus 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

Mobile radar ?

Swedish - Finnish Antarctic Stations Wasa / Aboa

Mobile MST Radar ? FMI/Univ. Helsinki Aerosol instruments Mini-MAX DOAS ?

Organisational Aspects :

FORSKNINGSSTRATEGIER 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 forskningsfronter IRF: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 forskningsprogram Nedan 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