南極ドームふじアイスコアの年代補正モデルによる氷年代軸決定の試み

Open House, ISM in Tachikawa, 2012.6.15統計数理研究所オープンハウス（立川）、H24.6.15ポスター発

Seasonal variation of air transport in the Antarctic and Atmospheric Circulation in 1997

To better understand how present and past climates at Syowa Station, Antarctica relate to climate elsewhere, we analyzed the tropospheric air transport to Syowa Station for the year 1997 using a dataset from the European Centre for Medium Range Weather Forecasts(ECMWF). The five-day trajectories of the air parcels were estimated and analyzed. In the middle troposphere in winter, air parcels were usually from the lower troposphere over the Atlantic. However, in January, most of the air parcels came from latitudes higher than 60°S . The trajectories had little vertical motion and were associated with a low pressure system that forms along the coastal region of Antarctica only in summer. In the lower troposphere, trajectories could be classified as originating in one of three regions: the Southern Ocean, the continental interior, and the east coast. In contrast to the middle troposphere, air parcels from the Southern Ocean had the lowest frequency, irrespective of the time of year. This is partially due to a low pressure system that blocks air parcels from outside the continent. Most trajectories are affected by the drainage flow. An amplified quasi-stationary planetary wave for September to November and a blocking circulation in June make trajectories pass over Antarctica

Obstructions of Portal Veins and Tumor Numbers Are Associated with Humped Hepatocellular Carcinoma

Tumor protrusion in hepatocellular carcinoma (HCC) is one of the risk signs of tumor rupture. Despite curative tumor treatments, HCC recurrences sometimes occur with rapidly growing humped or ruptured HCC in small sized tumors. The aim of this study was to clarify the characteristics of humped HCC clinically and radiologically associated with tumor progression, liver damage, and treatment. The subjects were 179 consecutive HCC patients who underwent angiographic examination. Dynamic studies, using helical computed tomography and magnetic resonance imaging were assessed, and the HCC area were measured. The tumor-node-metastasis (TNM) stage differed significantly between the humped and non-humped HCC groups. Humped HCC was more frequently observed in the right lobe (29.3% of right-lobe HCCs) than in the left (10.1%;p＝0.003). Analysis of recurrent HCC revealed that patients with multiple treatments of >4 sessions had more humped HCC (33.8%) than those with 1-3 sessions (16.7%;p＝0.042). Multivariate regression analysis revealed that tumor invasion in the portal vein, rather than large tumor size, was significantly associated with tumor protrusion. HCC recurrence with humped HCC occurs often in patients with multiple treatments. Tumor factors of the TNM classification, especially tumor invasion in the portal vein, might be associated with the mechanisms of tumor protrusion

The snowfall-cloud at Syowa Station identified by convolutional neural network

The Tenth Symposium on Polar Science/Ordinary sessions: [OM] Polar Meteorology and Glaciology, Wed. 4 Dec. / 2F Auditorium, National Institute of Polar Researc

ナンキョクイキ ニ オケル タイキ ジュンカン ト ヒョウショウ ヘノ タイキ ユソウ

日本の観測拠点のうち,長期間観測データが蓄積されている沿岸部の昭和基地と,氷床コア掘削地点である内陸部のドームふじ基地を例にとり,それぞれに到達する大気輸送経路の特徴を調べた.大気輸送経路の算出にはNIPR流跡線モデルを用い,ERA-40再解析データを入力データとした.昭和基地については対流圏中層と下層による違いについても調べた. 5日前の空気塊の位置を起源とし,その季節変化を調べた.昭和基地対流圏中層に到達する空気塊は,年間を通じて海起源が約8割を占め,陸起源は2割にとどまっていた.海起源の中では,大西洋起源が約7割となっていた.昭和基地対流圏下層へ到達する空気塊は,海起源と陸起源の比率がほぼ等しく,中層よりもインド洋側・内陸側から西向きの大気輸送が卓越していた.ドームふじ基地へ到達する空気塊の,海・陸起源の比率は昭和基地対流圏下層と同様に半々であるが,一年周期の季節変化がみられた.This study investigate the seasonal variations and features of air transport routes to the Japanese stations, "Syowa Station" and "Dome Fuji Station", which are located on the coastal and in the continental interior, respectively. For backward trajectory calculation, the NIPR trajectory model (NITRAM) and ERA-40 reanalysis were used. At Syowa Station, the difference of air transport between the mid and lower troposphere (500, 850 hPa, respectively) is of interest. We assorted trajectories into four regions by their locations 5-days before, which indicate the origin area of the air parcel. At 500 hPa over Syowa Station, about 80% of air parcels came from the sea, whereas at 850 hPa, half of trajectories came from Antarctica. Generally, air parcels came from west of Syowa Station at 500 hPa (69%). The easterly wind zone covered the station, so air parcels were liable to come from the east and the continental interior at 850 hPa. At 500 hPa over Dome Fuji Station, about 50% of air parcels from the ocean had traveled to the station and there is an annual variation in the origins

Climatic and atmospheric histories over the past 700,000 years from the Dome Fuji deep ice core, Antarctica

第3回極域科学シンポジウム　横断セッション「海・陸・氷床から探る後期新生代の南極寒冷圏環境変動」11月26日（月） 国立国語研究所 ２階講