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AEROSOL CHARACTERISTICS OVER NORWEGIANARCTIC: RESULTS FROM INDIAN SCIENTIFIC
EXPEDITIONS
Mukunda M Gogoi1*, S Suresh Babu1, K Krishna Moorthy1, Jai Prakash
Chaubey1, Vijayakumar S Nair1, Manoj M R1, Sobhan Kumar Kompalli1, Lakshmi
N B1, Roseline C Thakur2, Thamban Meloth2, S Rajan2
1

Space Physics Laboratory, Vikram Sarabhai Space Centre,
Thiruvananthapuram-695022, India

2

National Centre for Antarctic and Ocean Research, Vasco da Gama,Goa-403804, India
E-mail: dr_mukunda@vssc.gov.in; mukunda.mg@gmail.com

In the context of global climate change, there is an increased need inunderstanding the role of atmospheric aerosols in arctic atmosphere in changing
the snow Albedo, phenomenon like ‘Arctic haze’ and ‘thinning of Arctic Sea’ andperturbation to the radiation balance in the Arctic region. As a part of Indian
Scientific Expedition to Arctic, extensive measurements of scattering andabsorption properties of aerosols have been in progress at Ny Alesund (78.9°N,11.9°E) in Svalbard archipelago of Norwegian Arctic since June 2011. The
results from the year round measurements indicate that the mass concentrationof Black Carbon (BC) aerosols showed large annual variation with values as low
as ~5 ng m-3 to as high as ~ 300 ng m-3 (during winter/spring). Similarly, thescattering coefficients also showed significant annual variation with higher values(~ 30 Mm-1) during the winter and spring. However, the aerosol single scattering
albedo was lower (as low as 0.85) during the summer. In addition, theinvestigation of aerosol black carbon in the snow samples collected around NyAlesund during the onset of Arctic spring (2012) indicates that the mean
concentration of BC in snow varied from ~ 1 to 5 ppb; while the corresponding
atmospheric BC varied from ~ 25 ng m-3 to 50 ng m-3. Since there was no
significant snowfall during this period, the observed BC in snow is usuallyassociated with dry deposition. The details of the observational program and theresults will be presented.

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VWUDWRVSKHUHWURSRVSKHUHFRQQHFWLRQH[WHQGLQJWKHDQDO\VLVSHULRGWR㻔㻓㻙㻪㻔㻐㻳㻖G1–P3COMBINED MEASUREMENTS OF GRAVITY WAVES WITHAN AIRGLOW IMAGER AND ALOMAR LIDARS IN NORWAY
S. Suzuki1, F.-J. Luebken2, G. Baumgarten2, N. Kaifler2, R. Eixmann2,B. P. Williams3, and T. Nakamura4
1

Solar-Terrestrial Environment Laboratoty, Nagoya University (Nagoya, Japan)

2

Leibniz-Institute of Atmospheric Physics (Kühlungsborn, Germany)

3

GATS, Incorporated (Boulder, CO, United States)

4

National Institute of Polar Research (Tachikawa, Japan)

shin@stelab.nagoya-u.ac.jp
To investigate the vertical propagation of gravity waves from the lower tothe upper atmosphere, combined measurements with an airglow imager andlidars were carried out at the Arctic Lidar Observatory for Middle Atmosphere
Research (ALOMAR) station (69.3ºN, 16.0ºE) in Norway. Airglow imaging reveals
the two-dimensional structure of gravity waves in the mesopause region, while theALOMAR Rayleigh/Mie/Raman (RMR) lidar and sodium lidar provide the verticalstructures between the stratosphere and the lower thermosphere. On 26
November 2010, the imager identified a mesoscale gravity wave structure in thesodium airglow that had a horizontal wavelength of 277 km, a wave period of 59
min, and propagated northeastward at a phase speed of 78 m s1. Simultaneous
lidar measurements also showed upward wave signatures with a similar wave
period in the temperature perturbations; the vertical wavelength of the upward
wave seen in the temperature data is consistent with the dispersion relation for
gravity waves. Based on the combined measurements with the imager andsodium lidar, momentum flux of this gravity wave was estimated to be 1.0 m2 s2 atthe sodium airglow height. Ray-tracing analysis suggested that the observed
gravity wave was generated by a distortion of the polar jet at the tropopause via ageostrophic adjustment process.

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Variations of the polar lower thermosphere, mesosphere,and ionosphere due to a SSW ~ A case study of theJanuary 2012 event~Nozawa1, S., T. Kawahara2, T. Tsuda3, T. Kawabata1, N. Saito4, S. Wada4,Y. Ogawa3 and M. Tsutsumi3
1STEL, Nagoya University
Shinshu University
3NIPR
4
RIKEN
Corresponding author: nozawa@stelab.nagoya-u.ac.jp
2

Effects of Sudden Stratospheric Warming (SSW) on the Thermosphere have been
paid great attentions for last half decades in terms of the atmospheric verticalcoupling process. We report results of a case study of the January 2012 SSWevent based on observations made at Tromsø (69.6°N, 19.2°E). In Tromsø, wehave been conducting comprehensive observations using European Incoherent
SCATer (EISCAT) radars, MF radar, meteor radar (owned by NIPR), Fabry-Perot
Interferometer (FPI), aurora imagers, photometer, and sodium LIDAR. From 0739
UT on January 13, 2012 to 2300 UT on January 23, 2012, the EISCAT UHF radar
was operated with a scanning mode (so-called ip2 mode) and succeeded inobtaining good quality data (ionospheric parameters above 90 km, and neutral
wind velocity between 90-120 km) over the time interval. The weather was good,
and then we succeeded in obtaining neutral temperature data for nine nights(January 13, 14, 17, 18, 19, 20, 21, 22, 23) by sodium LIDAR. MF and meterradars conducted wind observations in the mesosphere. We will show results ofa case study on this event, and discuss how the lower
thermosphere/mesosphere/ionosphere varied during the SSW event.

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SODIUM DENSITY VARIATION DURING AURORALPARTICLE PRECIPITATIONS
T. T. Tsuda1, S. Nozawa2, T. D. Kawahara3, T. Kawabata2, N. Saito4, S. Wada4,
S. Oyama2, Y. Ogawa1, S. Suzuki2, T. Takahashi2, T. Nakamura1
1

National Institute of Polar Research (Tachikawa, Tokyo, Japan)

2

Solar-Terrestrial Environment Laboratory, Nagoya Univ. (Nagoya, Aichi, Japan)

3

Faculty of Engineering, Shinshu Univ. (Nagano, Nagano, Japan)

4Advanced Science Institute, RIKEN (Wako, Saitama, Japan)

E-mail address of corresponding author: tsuda.takuo@nipr.ac.jp
Sodium atom layer is generally distributed at 80-100 km. One ofmysterious subjects on high-latitude sodium layers is relationship between auroral
particle precipitations and sodium atom layer variations. A previous study
suggested a sodium column density decrease during a geomagnetic active period
due to that the particle precipitations accompanied by electron density
enhancement could induce ionization of sodium atom through their ion-molecule
chemistry. Another study pointed a possibility of sodium density increase. For thisreason, it is suggested that precipitating particle bombardment on meteoric smoke
particles can sputter sodium atoms from the smoke particles. On the other hand,ionospheric electric fields, which may become more significant near auroral
precipitating regions, could induce ion motions (i.e. can generate sodium ion
convergence and/or divergence), and then also could affect generation and/orloss processes of sodium atoms through their ion-molecule chemistry. Thus, forthe evaluation of the causarity, it is important to distinguish the effects of auroral
particle precipitations and ionospheric electric fields. Using a sodium lidar (whichwas installed in early 2010) and European incoherent scatter (EISCAT) radar atTromsø, Norway (69.6ºN, 19.2ºE), we have investigated, for the first time, that theactual effect of the particle precipitation to the sodium density variations without
electric filed injection. In the nighttime observation on 24 January 2012, wedetected a significant decrease of sodium atom density coincied with electron
density enhancements (implying strong particle precipitations) and low ion
temperatures (implying no electric field injections). These results strongly
suggested that auroral particle precipitations induced sodium atom density
decrease.

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G1–P6

CURRENT STATUS OF THE STEL OPTICALOBSERVATIONS AT THE TROMSØ EISCAT RADAR SITE
Shin-ichiro Oyama1,
Yuichi Otsuka1,

Satonori Nozawa1,

Ryoichi Fujii1,

Kazuo Shiokawa1,

Toru Takahashi1

1Solar-Terrestrial Environment Laboratory, Nagoya University

soyama@stelab.nagoya-u.ac.jp
Solar-Terrestrial Environment Laboratory (STEL), Nagoya University has
operated various kinds of optical instruments for more than 10 years at theTromsø EISCAT (European Incoherent Scatter) radar site in Norway (69.6ºN,19.2ºE), which is one of the state-of-art observatories for the upper atmosphericphysics at high latitudes. Seven instruments are now in operation regularly from
October to March: (1) a three-wavelength photometer (simultaneously measuring
the emission intensity of aurora at 427.8 nm, 630.0 nm, and 557.7 nm), which isfixed to look along the magnetic field line, (2) two digital cameras for monitoring
weather and aurora, (3) a proton all-sky camera (wavelength at 486.1 nm), (4)multi-wavelength all-sky camera (programmatically selecting one of the opticalfilters at 557.7 nm, 630.0 nm, near-infrared OH band, 589.3 nm, 572.5 nm, and732.0 nm), (5) a Fabry-Perot interferometer (programmatically selecting one of theoptical filters at 557.7 nm, 630.0 nm, and 732.0 nm), (6) a sodium LIDAR. All ofthem (except for the sodium LIDAR) are automatically operated. Theseinstruments have joined many campaign observations with the EISCAT radars,
rockets, satellites, and other ground-based instruments by adjusting theobservation mode. The quick looks are available to see on the web at:www.stelab.nagoya-u.ac.jp/~eiscat/data/EISCAT.html
This paper reports the current operation status and some new results of these
optical instruments until the end of 2012.

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CURRENT STATUS OF UPPER ATMOSPHERE PHYSICSOBSERVATION IN ICELAND IN 2012
Akira Kadokura 1, N. Sato 1, H. Yamagishi 1, Y. Tanaka 1, Y. Sato1, T. Koshida1,M. Taguchi 2, T. Ono 3, T. Motoba 4, K. Hosokawa 5, Gunnlaugur Bjornsson 6
1National Inst. of Polar Research, 10-3, Midoricho, Tachikawa, 190-8518, Japan

2Rikkyo Univ., 3-34-1 Nishi-Ikebukuro,Toshima-ku, Tokyo 171-8501, Japan

3Tohoku Univ., 6-3, Aoba, Aramaki, Aoba-ku, SendaiI 980-8578, Japan

4

The Johns Hopkins University Applied Physics Laboratory, 11100 Johns

Hopkins Road, Laurel, Maryland 20723, U.S.A.
5

Univ. Electro-Communications, 1-5-1 Chofugaoka, Chofu-shi 182-8585, Japan

6Science Institute, University of Iceland, Dunhagi 3, IS-107 Reykjavik, Iceland

kadokura@nipr.ac.jpSyowa Station (SYO) in Antarctica and Iceland in the northern hemisphere
are located at auroral latitudes, and in the geomagnetic conjugate relationship,
where both are connected with each other with a same magnetic field line.
Conjugate observations of auroral phenomena in Iceland have been carried out
since 1984 as a collaborative project between National Institute of Polar Research(NIPR), Japan and University of Iceland. At present, there are two observatories inIceland; Husafell (HUS) and Tjornes (TJR). Conjugate point of Syowa, which wasinitially located between HUS and TJR in 1984, is now located just north-eastwardof TJR. Various ground-based instruments are operated now. We will show thecurrent status of the upper atmosphere physics observations in Iceland as of2012.

Fig.1. Map of Iceland.
Indicated are locations ofobservatories in Iceland(HUS, TJO, AED), andgeomagnetic traced
footprint of Syowa Station(star symbols) from 1980to 2010.

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