Lower tropospheric vertical distribution of aerosol particles over Syowa Station, Antarctica from spring to summer 2004

Vertical distributions of atmospheric aerosol particles were measured nine times up to 5200 m a.s.l. using an aircraft over Syowa Station, East Antarctica during September-December 2004. Measurements were made for number concentrations of condensation nuclei (CN, Dp>10 nm), number-size distribution larger than 0.3 μm diameter, air temperature, humidity, and GPS position. During spring, the vertical profile of CN concentration showed large variability (100-1000 cm^(-3)), but it was mostly constant in summer. Vertical profiles of number-size distribution larger than 0.3 μm showed a systematic shift at altitudes greater than 4000 m. Both concentrations of aerosol number for Dp>0.3 μm and integrated volume between 0.3 and 1.0 μm showed constantly lower values at altitudes greater than 4000 m. These data suggest that the shift of aerosol parameters results from depletion of coarse particles such as sea salts. Maximum concentrations of the volume and CN were obtained respectively from the profiles on 7 October and 29 November 2004. These events are interpreted as sources and transport processes based on synoptic meteorological data, an ocean color index produced by SeaWiFS, and backward air trajectory analysis

Seasonal variation of chemical composition of aerosols at Syowa Station, Antarctica in 2001

Antarctic aerosols collected at Syowa Station in 2001 were analyzed to investigate their seasonal variations and long-range transport of anthropogenic aerosols. The measured chemical species were elemental carbon(E.C.) and organic carbon(O.C.) using a combustion technique, SO_4^, NO_3^-, Cl^-, Na^+, NH_4^+, K^+, Ca^ and Mg^ using ion chromatographs, and metals such as Al, V, Cr, Mn, Fe, Co, Ni, Zn and Pb using an inductively coupled plasma mass spectrometer. Total mass concentration of aerosols ranged from 0.366 to 2.72μg/m^3 and increased from winter to spring. The NO_3^- concentration was lower than 0.01μg/m^3 in March-July; in contrast, it was higher than 0.02μg/m^3 in August-November. Concentration of elemental carbon was relatively low in April-June and was high in March, October and November. In October and November, NO_3^- concentration was also high. Therefore, the air mass was possibly affected by biomass burning. The concentration of SO_4^- was low around 0.02μg/m^3 in May-July, and it increased to higher than 0.1μg/m^3 in August-December. The concentrations of Al, V, Co, Ni and Pb were sometimes lower than the detection limits. Nevertheless, spikes of the highest concentrations of V, Cr, Fe, Co, Ni, Zn and Pb were recorded in August-October, while V and Fe showed second spikes in March. The enrichment factors of Cr, Ni, Zn and Pb were high during 13-20 September and 12-22 October. The E.C. concentrations in these periods were also relatively higher than before and after the sampling periods. Moreover, blizzards occurred in these periods

Ecdysone-dependent and ecdysone-independent programmed cell death in the developing optic lobe of Drosophila

AbstractThe adult optic lobe of Drosophila develops from the primordium during metamorphosis from mid-3rd larval stage to adult. Many cells die during development of the optic lobe with a peak of the number of dying cells at 24h after puparium formation (h APF). Dying cells were observed in spatio-temporal specific clusters. Here, we analyzed the function of a component of the insect steroid hormone receptor, EcR, in this cell death. We examined expression patterns of two EcR isoforms, EcR-A and EcR-B1, in the optic lobe. Expression of each isoform altered during development in isoform-specific manner. EcR-B1 was not expressed in optic lobe neurons from 0 to 6h APF, but was expressed between 9 and 48h APF and then disappeared by 60h APF. In each cortex, its expression was stronger in older glia-ensheathed neurons than in younger ones. EcR-B1 was also expressed in some types of glia. EcR-A was expressed in optic lobe neurons and many types of glia from 0 to 60h APF in a different pattern from EcR-B1. Then, we genetically analyzed EcR function in the optic lobe cell death. At 0h APF, the optic lobe cell death was independent of any EcR isoforms. In contrast, EcR-B1 was required for most optic lobe cell death after 24h APF. It was suggested that cell death cell-autonomously required EcR-B1 expressed after puparium formation. βFTZ-F1 was also involved in cell death in many dying-cell clusters, but not in some of them at 24h APF. Altogether, the optic lobe cell death occurred in ecdysone-independent manner at prepupal stage and ecdysone-dependent manner after 24h APF. The acquisition of ecdysone-dependence was not directly correlated with the initiation or increase of EcR-B1 expression

“Sizing” Heterogeneous Chemistry in the Conversion of Gaseous Dimethyl Sulfide to Atmospheric Particles

The oxidation of biogenic dimethyl sulfide (DMS) emissions is a global source of cloud condensation nuclei. The amounts of the nucleating H_2SO_4(g) species produced in such process, however, remain uncertain. Hydrophobic DMS is mostly oxidized in the gas phase into H_2SO_4(g) + DMSO(g) (dimethyl sulfoxide), whereas water-soluble DMSO is oxidized into H_2SO_4(g) in the gas phase and into SO_4^(2–) + MeSO_3– (methanesulfonate) on water surfaces. R = MeSO_3–/(non-sea-salt SO_4^(2–)) ratios would therefore gauge both the strength of DMS sources and the extent of DMSO heterogeneous oxidation if R_(het) = MeSO_3–/SO_4^(2–) for DMSO(aq) + ·OH(g) were known. Here, we report that R_(het) = 2.7, a value obtained from online electrospray mass spectra of DMSO(aq) + ·OH(g) reaction products that quantifies the MeSO_3– produced in DMSO heterogeneous oxidation on aqueous aerosols for the first time. On this basis, the inverse R dependence on particle radius in size-segregated aerosol collected over Syowa station and Southern oceans is shown to be consistent with the competition between DMSO gas-phase oxidation and its mass accommodation followed by oxidation on aqueous droplets. Geographical R variations are thus associated with variable contributions of the heterogeneous pathway to DMSO atmospheric oxidation, which increase with the specific surface area of local aerosols

Atmospheric sea-salt and halogen chemistry in the Antarctic region

The Tenth Symposium on Polar Science/Ordinary sessions: [OM] Polar Meteorology and Glaciology, Thu. 5 Dec. / 2F Auditorium , National Institute of Polar Researc

ナンキョク ショウワキチ デノ ケイリュウ キキュウ ヲ モチイタ カブ タイリュウケン エアロゾル カンソク ノ ホウコク

第46次南極地域観測隊は,上空の大気エアロゾルの性状と数濃度の季節を捉えるため,昭和基地において2005年1月6日から12月11日かけて,27回の係留気球によるエアロゾル観測を実施した.この観測は,第VI期5カ年計画のプロジェクト研究観測で行われている「エアロゾル集中観測」の一環として実施された.ここでは,通年で係留気球観測を実施するための計画や準備,実際の観測状況,問題点について報告する.The 46th Japanese Antarctic Research Expedition (JARE-46) carried out twenty seven tethered-balloon-borne aerosol measurements at Syowa Station for better understanding of aerosol chemical and physical properties in the lower troposphere from 6th January 2005 until 11 December 2005. This report summarizes the plan, preparation, field activities and some troubles/problems in the tethered-balloon observations

ダイ48ジ ナンキョク チイキ カンソク ナツタイ ノ S17 コウクウ キョテン ニ オケル カツドウ ホウコク ニチドク キョウドウ コウクウキ カンソク ニ カンシテ

本稿は,第48次南極地域観測隊夏隊が昭和基地近くの大陸氷床上のS17に滑走路を開設して行った航空機観測,及び地上での観測に関する活動報告である.S17航空拠点(以下,S17拠点)において実施したそれぞれの観測の規模や,基地運営の具体的な事柄を記載する.基地運営には拠点の開設・撤収・維持及び他の沿岸調査隊活動等の支援が含まれており,それらの情報は取りまとめて付録として添付した. ドイツのアルフレッド・ウェゲナー極地海洋研究所(AWI)と共同で行った航空機Polar2を使った日独共同航空機観測(ANTSYO-II:Antarctic Flight Mission at Syowa Region II)は,1月7日から24日にかけて飛行回数15回,総飛行時間約42時間を行った.地上観測として,気温,湿度,風向・風速,気圧などの一般的気象要素に加えて,雲底計,エアロゾル計数計,雪粒子計数計,超音波風速計,放射計による連続計測を行った.航空機観測の終了後に小型模型飛行機による大気境界層観測を試みた. 航空機に搭乗する研究者,技術者,パイロットは日本,ドイツ,スウェーデンからの9名で構成され,航空機によりケープタウン(南アフリカ共和国)からNovo基地(南極,ロシア)を経由しS17拠点に出入りした.S17拠点を維持する研究者,技術者は日本からの4名で構成され,観測船「しらせ」により往復した.This report summarizes activity at the S17 base on the Antarctic ice sheet near Syowa Station in 2006-2007 summer. The description focuses on the period from the opening to closing of the S17 base. The appendix lists daily activity in detail. The atmospheric aircraft observation (ANTSYO II: Antarctic Flight Mission at Syowa Region II) was carried out by using the S17 base runway in cooperation with AWI (Alfred Wegener Institute for Polar and Marine Research, Germany). From 7th to 24th of January 2007, 15 times observation flights totaling 42 hours were carried out successfully. The surface meteorological observation system (air temperature, humidity and so on), ceilometer, aerosol particle counter, snow particle counter, anemometer and radiometer were maintained for about a month. Additionally, small model airplanes were used to obtain meteorological data in the boundary layer. The personnel who took the aircraft observations included Japanese, Germans and Swedes, all of whom came into/out of S17 via aircrafts. Others who maintained the S17 base and took ground based observations came into/out of Antarctica via the Japanese icebreaker Shirase

Ambient fine and coarse particles in Japan affect nasal and bronchial epithelial cells differently and elicit varying immune response

Ambient particulate matter (PM) epidemiologically exacerbates respiratory and immune health, including allergic rhinitis (AR) and bronchial asthma (BA). Although fine and coarse particles can affect respiratory tract, the differences in their effects on the upper and lower respiratory tract and immune system, their underlying mechanism, and the components responsible for the adverse health effects have not been yet completely elucidated. In this study, ambient fine and coarse particles were collected at three different locations in Japan by cyclone technique. Both particles collected at all locations decreased the viability of nasal epithelial cells and antigen presenting cells (APCs), increased the production of IL-6, IL-8, and IL-1β from bronchial epithelial cells and APCs, and induced expression of dendritic and epithelial cell (DEC) 205 on APCs. Differences in inflammatory responses, but not in cytotoxicity, were shown between both particles, and among three locations. Some components such as Ti, Co, Zn, Pb, As, OC (organic carbon) and EC (elemental carbon) showed significant correlations to inflammatory responses or cytotoxicity. These results suggest that ambient fine and coarse particles differently affect nasal and bronchial epithelial cells and immune response, which may depend on particles size diameter, chemical composition and source related particles types