Tropical Intraseasonal Modes of the Atmosphere

Artículo científico -- Universidad de Costa Rica. Centro de Investigaciones Geofísicas, 2014. Este documento es privado debido a limitaciones de derechos de autor.Tropical intraseasonal variability (TISV) of the atmosphere describes the coherent variability in basic state variables, including pressure, wind, temperature, and humidity, as well as in the physical phenomena associated with the covariability of these parameters, such as rainfall and cloudiness, over synoptic (∼1,000 km,∼1–10 days) to planetary (∼10,000 km,∼10–100 days) scales. In the past, the characteristics of individual TISV modes were studied separately, and much has been learned from this approach. More recent studies have increasingly focused on the multiscale nature of these modes, leading to exciting new developments in our understanding of tropical meteorology. This article reviews the most recent observations of TISV and its associated impacts on regional weather, short-term climate patterns, and atmospheric chemical transports, as well as the ability of numerical models to capture these interacting modes of variability. We also suggest where the field might focus its efforts in the future.Universidad de Costa Rica, National Science Foundation (NSF) and National Oceanic and Atmospheric Administration (NOAA). Part of the research for this study was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration..UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones Geofísicas (CIGEFI

Spatial and diurnal variations of storm heights in the East Asia summer monsoon: storm height regimes and large-scale diurnal modulation

This study investigates the spatial and diurnal variation of storm height in the East Asia summer monsoon region using 13-year Tropical Rainfall Measuring Mission Precipitation Radar data. Precipitating storms are classified as shallow (<5 km), middle (5-10 km), and deep (>10 km) depending the height. Four different regimes are identified to characterize the region: the continental (CT) shallow regime over inland China with elevated terrain, the CT deep over the Chinese Plain, the coastal (CS) middle over the East China Sea and South Sea of Korea, and the CS shallow over the south coastal area of Japan. This regime separation reflects well the distinctive regional difference in the rainfall contribution by each storm type. The occurrence frequencies of shallow, middle, and deep storms exhibit pronounced diurnal variation as well, but with significant differences in the amplitude and phase across the regimes. These lead to a diversity in the diurnal variation of surface rainfall such as bimodal morning and late evening peaks in the two CT regimes and the single morning peak in the two CS regimes. Processes involved in the diurnal variation of storms are different across the regimes, indicating difference in the contributing role of surface heating, large-scale diurnal circulation, and diurnal propagations of convective systems. The storm height also affects the rain intensity. This study highlights that the East Asia summer monsoon has distinctive sub-regional variation of the storm height distribution, thereby providing unique differences in the rainfall amount, intensity, and the diurnal variation. © 2015 Springer-Verlag Berlin Heidelbergclos