11:15 〜 11:30
[AAS08-09] The Role of Precipitation Efficiency in Scaling Radiation Influence on Precipitation Across Timescales
キーワード：季節内振動、放射フィードバック
Precipitation variability in the tropics is influenced by processes occurring across multiple timescales. Understanding the variability and drivers of these multiple timescales are essential for advancing our knowledge of tropical climate dynamics. Previous studies have explored the mechanisms behind these disturbances using the column-moist static energy (CMSE) budget but often focus on bulk moisture metrics or direct CMSE-precipitation relationships. However, the proportionality between moisture and precipitation varies across regions and seasons.<br _istranslated="1" />In this study, we examine the role of precipitation efficiency (PE) in modulating the 2-10-day and 20-60-day precipitation variability. PE, defined as the fraction of moisture converted into precipitation, serves as a key diagnostic for understanding how precipitation responds to moisture fluctuations. Radiation plays a key role in moisture buildup; thus, we focus on radiation. We assess how radiation influences precipitation variability through changes in PE by analyzing radiation projections normalized by moisture, precipitation, and their cross-spectrum.<br _istranslated="1" />Our results indicate that moisture-radiation feedback remains consistent across different timescales, yet the influence on precipitation varies due to differences in PE. At shorter timescales, the effect of radiation on precipitation is more pronounced because of weaker moisture-precipitation coupling, resulting in greater variations in PE. In contrast, at intraseasonal timescales, precipitation is primarily regulated by moisture storage, leading to more stability in PE. These findings highlight the importance of PE in scaling radiation influence on precipitation and offer insights into the mechanisms sustaining precipitation across different dynamical regimes. This study contributes to refining our understanding of tropical convection and improving precipitation representation in climate models.