Changes in aerosol content and temperature in the Antarctic spring stratosphere: Lidar measurement at Syowa Station (69°00′S, 39°35′E) in 1983, 1984 and 1985

1986 ◽  
Vol 13 (13) ◽  
pp. 1407-1410 ◽  
Author(s):  
Y. Iwasaka ◽  
T. Ono ◽  
A. Nonura
Keyword(s):  
Lidar Measurement ◽  
Syowa Station ◽  
The Antarctic

scholarly journals Snow density along the route traversed by the Japanese-Swedish Antarctic Expedition 2007/08

2012 ◽  
Vol 58 (209) ◽  
pp. 529-539 ◽  
Author(s):  
Shin Sugiyama ◽  
Hiroyuki Enomoto ◽  
Shuji Fujita ◽  
Kotaro Fukui ◽  
Fumio Nakazawa ◽  
...  
Keyword(s):  
Wind Speed ◽  
Surface Wind ◽  
Coastal Region ◽  
Snow Density ◽  
Syowa Station ◽  
Near Surface ◽  
A Value ◽  
Surface Snow ◽  
The Mean ◽  
The Antarctic

AbstractDuring the Japanese-Swedish Antarctic traverse expedition of 2007/08, we measured the surface snow density at 46 locations along the 2800 km long route from Syowa station to Wasa station in East Antarctica. The mean snow density for the upper 1 (or 0.5) m layer varied from 333 to 439 kg m-3 over a region spanning an elevation range of 365-3800 ma.s.l. The density variations were associated with the elevation of the sampling sites; the density decreased as the elevation increased, moving from the coastal region inland. However, the density was relatively insensitive to the change in elevation along the ridge on the Antarctic plateau between Dome F and Kohnen stations. Because surface wind is weak in this region, irrespective of elevation, the wind speed was suggested to play a key role in the near-surface densification. The results of multiple regression performed on the density using meteorological variables were significantly improved by the inclusion of wind speed as a predictor. The regression analysis yielded a linear dependence between the density and the wind speed, with a coefficient of 13.5 kg m-3 (m s-1)-1. This relationship is nearly three times stronger than a value previously computed from a dataset available in Antarctica. Our data indicate that the wind speed is more important to estimates of the surface snow density in Antarctica than has been previously assumed.

Sodium temperature lidar system for measuring the Antarctic mesopause region at Syowa station in 1999, 2000, and 2001

1998 ◽  
Author(s):  
Tsukasa Kitahara ◽  
Takuya D. Kawahara ◽  
Fumitoshi Kobayashi ◽  
Yasunori Saito ◽  
Akio Nomura
Keyword(s):  
Lidar System ◽  
Syowa Station ◽  
Mesopause Region ◽  
The Antarctic

Circumpolar occurrence of eugregarinid protozoanCephaloidophora pacificaassociated with Antarctic krill,Euphausia superba

2008 ◽  
Vol 20 (5) ◽  
pp. 437-440 ◽  
Author(s):  
Kunio T. Takahashi ◽  
Masaki Kobayashi ◽  
So Kawaguchi ◽  
Junko Saigusa ◽  
Atsushi Tanimura ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Antarctic Krill ◽  
Geographical Location ◽  
Protozoan Parasite ◽  
Euphausia Superba ◽  
Maturity Stage ◽  
Syowa Station ◽  
Frequency Distributions ◽  
The Mean ◽  
The Antarctic

AbstractThe geographical distribution of protozoan parasiteCephaloidophora pacificaAvdeev (Order Eugregarininda) associated with Antarctic krill,Euphausia superba, was examined in samples collected from the vicinity of the Antarctic Peninsula, near Syowa Station, and Pacific and Indian sectors of the Southern Ocean.Cephaloidophora pacificawas found at all stations around the Antarctic, with 96.4% of the euphausiids infected (n = 195). The numbers ofC. pacificaper krill ranged from 0 to 8089 krill-1, and the average was 350.0 ± 787.8 (mean ± SD). The frequency distributions ofC. pacificashowed an overdispersed parasite population (i.e. the variance was greater than the mean) at all locations. Statistical analysis showed that whilst the geographical location did not have a significant effect on intensity ofC. pacificathe maturity stage of krill did, with an increasing intensity of infection as krill matures. The infestation ofE. superbaby eugregarinid protozoan is considered to be a circum-Antarctic phenomenon, and it occurs equally throughout the Southern Ocean.

scholarly journals A Study of Multiple Tropopause Structures Caused by Inertia–Gravity Waves in the Antarctic

2015 ◽  
Vol 72 (5) ◽  
pp. 2109-2130 ◽  
Author(s):  
Ryosuke Shibuya ◽  
Kaoru Sato ◽  
Yoshihiro Tomikawa ◽  
Masaki Tsutsumi ◽  
Toru Sato
Keyword(s):  
Gravity Waves ◽  
General Circulation ◽  
Climate Models ◽  
Lower Stratosphere ◽  
Circulation Model ◽  
Cold Bias ◽  
Syowa Station ◽  
Dynamical Mechanism ◽  
The Antarctic ◽  
Inertia Gravity Waves

Abstract Multiple tropopauses (MTs) defined by the World Meteorological Organization are frequently detected from autumn to spring at Syowa Station (69.0°S, 39.6°E). The dynamical mechanism of MT events was examined by observations of the first mesosphere–stratosphere–troposphere (MST) radar in the Antarctic, the Program of the Antarctic Syowa MST/Incoherent Scatter (IS) Radar (PANSY), and of radiosondes on 8–11 April 2013. The MT structure above the first tropopause is composed of strong temperature fluctuations. By a detailed analysis of observed three-dimensional wind and temperature fluctuation components, it is shown that the phase and amplitude relations between these components are consistent with the theoretical characteristics of linear inertia–gravity waves (IGWs). Numerical simulations were performed by using a nonhydrostatic model. The simulated MT structures and IGW parameters agree well with the observation. In the analysis using the numerical simulation data, it is seen that IGWs were generated around 65°S, 15°E and around 70°S, 15°E, propagated eastward, and reached the region above Syowa Station when the MT event was observed. These IGWs were likely radiated spontaneously from the upper-tropospheric flow around 65°S, 15°E and were forced by strong southerly surface winds over steep topography (70°S, 15°E). The MT occurrence is attributable to strong IGWs and the low mean static stability in the polar winter lower stratosphere. It is also shown that nonorographic gravity waves associated with the tropopause folding event contribute to 40% of the momentum fluxes, as shown by a gravity wave–resolving general circulation model in the lower stratosphere around 65°S. This result indicates that they are one of the key components for solving the cold-bias problem found in most climate models.

scholarly journals Seasonal variations and vertical features of aerosol particles in the Antarctic troposphere

2011 ◽  
Vol 11 (3) ◽  
pp. 7555-7591 ◽  
Author(s):  
K. Hara ◽  
K. Osada ◽  
C. Nishita-Hara ◽  
T. Yamanouchi
Keyword(s):  
Seasonal Variations ◽  
Fine Particles ◽  
Austral Summer ◽  
Sea Salt ◽  
Coarse Particles ◽  
Free Troposphere ◽  
Syowa Station ◽  
Air Masses ◽  
Antarctic Expedition ◽  
The Antarctic

Abstract. Tethered balloon-borne aerosol measurements were conducted at Syowa Station, Antarctica during the 46th Japanese Antarctic expedition (2005–2006). The CN concentration reached a maximum in the summer, although the number concentrations of fine particles (Dp > 0.3 μm) and coarse particles (Dp > 2.0 μm) increased during the winter-spring. The CN concentration was 30–2200 cm−3 near the surface (surface – 500 m) and 7–7250 cm−3 in the lower free troposphere (>1500 m). During the austral summer, higher CN concentration was often observed in the lower free troposphere, where the number concentrations in fine and coarse modes were remarkably lower. The frequent appearance of higher CN concentrations in the free troposphere relative to continuous aerosol measurements at the ground strongly suggests that new particle formation is more likely to occur in the lower free troposphere in Antarctic regions. Seasonal variations of size distribution of fine-coarse particles show that the contribution of the coarse mode was greater in the winter-spring than in summer because of the dominance of sea-salt particles in the winter-spring. The number concentrations of fine and coarse particles were high in air masses from the ocean and mid-latitudes. Particularly, aerosol enhancement was observed not only in the boundary layer but also in the lower free troposphere during and immediately after Antarctic haze events occurring in May, July, and September.

scholarly journals MF radar observations of the diurnal tide over Syowa, Antarctica (69° S, 40° E)

2009 ◽  
Vol 27 (7) ◽  
pp. 2653-2659 ◽  
Author(s):  
Y. Tomikawa ◽  
M. Tsutsumi
Keyword(s):  
Lower Thermosphere ◽  
Radar Data ◽  
Diurnal Tide ◽  
Syowa Station ◽  
Meridional Winds ◽  
Realistic Representation ◽  
Height Dependence ◽  
Mesosphere And Lower Thermosphere ◽  
The Antarctic ◽  
Mf Radar

Abstract. Characteristics of the diurnal tide in the Antarctic mesosphere and lower thermosphere (MLT) are investigated using 10 years of medium frequency (MF) radar data from Syowa Station (69° S, 39.6° E). Seasonal variations and height dependence of the diurnal amplitude and phase of zonal and meridional winds are mostly consistent with previous studies using the other Antarctic station data. The meridional momentum flux due to the diurnal tide shows a seasonal variation clearly different between above and below 90 km, which has never been reported in the literature. Finally, a cause of some discrepancy in the characteristics of the diurnal tide between the observation and simulation (i.e., GSWM-02) is discussed. It implies that the realistic representation of gravity waves in the simulation is crucial for realistic modeling of the diurnal tide.

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