Modification of equatorial disturbances over Indonesia maritime continent and its climatological significance

本研究的目的是阐明印度洋和太平洋之间印度尼西亚海洋大陆赤道对流云扰动的改变和重组。我们做了(i)研究基础设施的建立，（ii）数据库的建设，（iii）对流云系统及其组织的分析，（iv）对流系统组织的理论思考。在第一年（2001财年），我们通过安装计算机来构建(i)。我们收集了（ii）的观测数据，并对（iii）进行了分析。我们也开始学习（iv）。在第二年（2002财年），我们将（ii）与卫星观测数据和客观分析数据进行了比较。关于（iii），我们发现整个苏门答腊岛的云系统有一个巨大的日循环：在下午和午夜沿着中央山脊产生，然后向西和向东移动直到早晨。我们还发现，从印度洋向东移动的季际变化（超级云团的中间阶段）的干期抑制了这种日循环。关于（iv），我们研究了描述局地环流和经向环流的水平对流（或惯性重力波）方程组。在最后一年（2003财年），我们完成了这项研究。对于（iii），我们发现向西运动的日循环更为频繁（在整个苏门答腊岛上几乎贯穿全年），而向东运动在苏门答腊岛上的热带辐合带（ITCZ）内是有限的，该辐合带在苏门答腊岛上以年为周期向南北向移动。关于（iv），还尝试了数值计算来模拟云的产生和移动的日循环。这些结果在国际会议和期刊上发表，并在报告小册子中进行了总结。

The objective of this study was to clarify the modification and re-organization of equatorial convective cloud disturbances over the Indonesia maritime continent between Indian and Pacific Oceans. We did (i) establishment of study infrastructure, (ii) construction of database, (iii) analysis of convective cloud systems and their organization, and (iv) theoretical consideration on convection system organization.In the first year (FY 2001) we constructed (i) by installing a computer. We collected observational data for (ii), and analyzed them for (iii). We also started to study (iv). In the second year (FY 2002) we compared (ii) with data of satellite observations and objective analysis. Concerning (iii), we found out a giant diurnal cycle of cloud systems over the whole of Sumatera Island : Generation along the central mountain ridge during afternoon and midnight, and movement both westward and eastward until morning. We also found suppression of such a diurnal cycle in a dry phase of infra-seasonal variations (intermediate of super cloud clusters) moving eastward from Indian Ocean. Concerning (iv), we studied the equation system for horizontal convection (or inertio-gravity waves) which describing both local and meridional circulations.In the final year (FY 2003) we complete the study. As for (iii) we found that the diurnal cycle of westward movement appears more frequently (almost throughout a year over the whole of Sumatera Island), whereas the eastward movement is limited inside the inter-tropical convergence zone (ITCZ) shifting north-southward over Sumatera Island with an annual cycle. Concerning (iv) a numerical calculation was also tried to simulate the diurnal cycle of cloud generation and movement.These results were presented in international meetings and journals, and summarized in a report booklet.