Trajectory analysis of Polar Patrol Balloon (PPB) flights in the stratosphere over Antarctica in summer and spring: A preliminary result

Actual trajectories of two PPB's which flew in the Antarctic stratosphere in austral summer and spring are compared with those calculated based on objective analysis data of Japan Meteorological Agency (JMA). The differences between the actual and calculated trajectories are discussed to check reliability of the JMA objective analysis data for the stratosphere, and to detect subsynoptic scale variability due to gravity waves and others

「レーダー大気物理学」研究室における理工学融合

第8回MUレーダー・赤道大気レーダーシンポジウム/第260回生存圏シンポジウム（2014年9月16日～17日, 京都大学宇治キャンパス

Maritime Continent Center of Excellence (MCCOE) Near future program related to monsoon in Indonesia

Agency for the Assessment and Application of Technology (BPPT) has established a one stop international center to study the interactions among land, sea, and atmosphere in the Indonesia Maritime Continent (IMC) and called as Maritime Continent Center of Excellence (MCCOE) on November 12, 2013. The IMC is at the central importance of El Nino Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD), and Asian monsoon that could influence directly on the Pacific and Indian oceans heat and water mass transport affecting on regional and even global climate changes. A small change in Sea Surface Temperature (SST) transmited from Pacific to Indian oceans through the current system so called Indonesian throughflow will affect the magnitude of monsoon and climate over the regions. In this critical perspective, the IMC in a whole system of earth, atmosphere, and ocean play important roles in regulating global climate changes. In this presentation, we will present all the near future programs related to monsoon that will be employed in the center, especially how intraseasonal variation interact with monsoon.Proceedings of GRENE 3rd Workshop (17-19 March, 2014, Bali, Indonesia

Rainfall-Driven Diurnal Cycle of Ciliwung River: Overview and Future Prospect

第8回MUレーダー・赤道大気レーダーシンポジウム/第260回生存圏シンポジウム（2014年9月16日～17日, 京都大学宇治キャンパス

Relationship between Wind and Precipitation Observed with a UHF Radar, GPS Rawinsondes and Surface Meteorological Instruments at Kototabang, West Sumatera during September-October 1998

Simultaneous observations with a UHF-band boundary layer radar (hereafter referred as BLR), GPS rawinsondes and a tipping-bucket-type rain gauge were conducted at Kototabang (0.20 S, 100.32 E, 865 m MSL), which is located on the mountainous region near Bukittinggi, West Sumatera Province, during 27 September–7 October 1998 (rainy season). Low-level (1–3 km) westerly wind stronger than 10 m/s was observed, and precipitation tended to occur when the low-level westerly wind became weak (2–5 October). Similar relationship was observed for two months (1 September–31 October 1998) during which only BLR and surface meteorological instruments were operated at Kototabang. NCEP/NCAR objective analysis, and GMS TBB data showed that the low-level (850 hPa) wind field, and cloud distribution, were both completely different between the Indonesian Archipelago (east of Kototabang) and the eastern Indian Ocean—including the Bay of Bengal (west of Kototabang)—during the analysis period. Two large-scale cloud disturbances existed along the equator in the western side (80 –100 E), but precipitation at Kototabang did not correspond to these cloud disturbances. The implication is that effects of the mountain range of Sumatera blocked the large-scale cloud disturbances over the Indian Ocean. The precipitation by local-scale cloud systems prevailed at Kototabang. The convergences of local circulations, which are generally dominant under weak background winds, are considered as the major cause of local-scale cloud systems

Impact of cross-equatorial Asian winter monsoon and the MJO on extreme precipitation over Western Java Island

The Indonesian capital of Jakarta experienced an extraordinary heavy precipitation/flood event in the middle of January 2013, as it did in 1996, 2002 and 2007. Heavy rainfall repeatedly occurred in a local area over western Java Island for 4 consecutive days 15-18 January. The central part of Jakarta city was inundated during 17-18 January 2013. This study examined the atmospheric circulations leading to the extreme precipitation event. Examination of ocean surface winds derived from the WindSat satellite measurements showed that a persistent, trans-equatorial, northerly wind took place 2-3 days prior to and during the heavy precipitation event, similar to that which occurred during the extreme precipitation event in Jakarta during late January into early February 2007. The strong, persistent, trans-equatorial Asian-winter monsoonal flow from the Northern Hemisphere was a main factor in the formation of extreme rain over western Java Island, as it induced an intensive low-level wind convergence along its leading edge over the island. In contrast to the extreme rain event of 2007, which was in an inactive MJO phase, the extreme precipitation/flood event of 2013 coincided with strong and coherent MJO activity with the enhanced convective phase centered on the western Pacific. The active phase of the MJO caused strong to moderate westerly to northwesterly winds at the levels from near the surface up to 400 hPa (~8 km) over Java Island in early to mid-January 2013. The westerly winds, in conjunction with the trans-equatorial monsoonal flow, strengthened the low level wind convergence near western Java Island, providing favorable conditions for precipitation. The results of the present study suggest that a persistent, trans-equatorial, northerly wind and the eastward propagation of an active phase of the MJO produced a great effect on the formation of extreme heavy rain over western Java Island.Proceedings of GRENE 3rd Workshop (17-19 March, 2014, Bali, Indonesia

Interannual rainfall variability over the Indonesian maritime continent and its relation to the Asian winter monsoon

Interannual rainfall variability over the Indonesian maritime continent is well related to the Indian Ocean Dipole (IOD) and El Nino-Southern Oscillation (ENSO) events [1]. Droughts conditions during the dry season (May?October) in northwestern Jawa occur in conjunction with simultaneous development of positive IOD and El Nino events, whereas wet conditions tend to appear in negative IOD rather than single La Nina events. On the other hand, interannual rainfall variation in the rainy season (November?April) is not closely related to ENSO/IOD, but rainfall tends to be abundant in neutral (non-ENSO/IOD) years. Correlation and composite analysis suggested that the rainy season rainfall would be influenced by the Asian winter monsoon strength and/or variability. In this study, we aim to investigate effects of Asian winter monsoon, especially for the cross-equatorial northerly surges (CENS) events over South China Sea and Jawa Sea, to interannual rainfall variability in the rainy season over northwestern Jawa. The CENS event was defined as the area-averaged northerly wind exceeding 5 m/s over South China Sea and Jawa Sea (105°E?115°E, 5°S?EQ) based on the QuikSCAT sea surface wind data [2]. During the analysis period (December 1999-March 2008), 53 CENS events were defined. We used surface daily rainfall data to investigate the rainfall variability and its relation to the CENS events. The occurrence frequency of CENS events was about 20%, whereas the contribution of CENS rainfall amount to the total rainfall amount in the rainy season was about 30?40%. The CENS events and rainfall peaks were well-corresponded including the Jakarta flood events in January 2002 and February 2007. Interannual variations of CENS events rainfall were well-corresponded to the interannual variations of the rainy season rainfall (correlation coefficient is 0.82). Obtained results suggested that CENS rainfall is one of the important factors to determine rainy season rainfall. It will be also suggested the CENS events would influence the rainfall variability in the rainy season over the southern part of the maritime continent, especially for the northern coastal region of the islands.Proceedings of GRENE 3rd Workshop (17-19 March, 2014, Bali, Indonesia

Increased Stathmin1 Expression in the Dentate Gyrus of Mice Causes Abnormal Axonal Arborizations

Pituitary adenylate cyclase-activating polypeptide (PACAP) is involved in multiple brain functions. To clarify the cause of abnormal behavior in PACAP deficient-mice, we attempted the identification of genes whose expression was altered in the dentate gyrus of PACAP-deficient mice using the differential display method. Expression of stathmin1 was up-regulated in the dentate gyrus at both the mRNA and protein levels. PACAP stimulation inhibited stathmin1 expression in PC12 cells, while increased stathmin1expression in neurons of the subgranular zone and in primary cultured hippocampal neurons induced abnormal arborization of axons. We also investigated the pathways involved in PACAP deficiency. Ascl1 binds to E10 box of the stathmin1 promoter and increases stathmin1 expression. Inhibitory bHLH proteins (Hes1 and Id3) were rapidly up-regulated by PACAP stimulation, and Hes1 could suppress Ascl1 expression and Id3 could inhibit Ascl1 signaling. We also detected an increase of stathmin1 expression in the brains of schizophrenic patients. These results suggest that up-regulation of stathmin1 in the dentate gyrus, secondary to PACAP deficiency, may create abnormal neuronal circuits that cause abnormal behavior