Regional Climate Projection Experiments on the Baiu Frontal Activity around the Japan Islands Using a Non-Hydrostatic Cloud-System-Resolving Model

Abstract Regional climate experiments focusing on the Baiu frontal precipitation were performed on the Earth Simulator using a non-hydrostatic cloud-system-resolving atmospheric model (NHM) with a horizontal resolution of 5 km (5km-NHM) and 1 km (1km-NHM). The outputs of an atmospheric general circulation model (AGCM) with a horizontal resolution of about 20 km were used as the boundary of 5km-NHM. The time-slice method in both the present and future climates was applied for the experiments of the AGCM and NHM. In the present climate experiments, it was evaluated that the precipitation distribution and precipitation frequency spectrum (PFS; frequency with intensities) of the 5km-NHM were well reproduced in comparison with those observed. Here, the AGCM in the present climate well reproduced the large-scale characteristics of the Baiu frontal precipitation. The Intergovernmental Panel on Climate Change (IPCC) A1B CO2 emission scenario was used to project changes in the precipitation property around the Baiu front due to global warm-ing in the future climate around the end of the 21st Century. The 5km-NHM projects not only an increase in precipitation around Western Japan associated with the elongation of the Baiu front due to global warming but also an intensification of precipitation associated with the enhancement of the convectively unstable strat-ification. The 1km-NHM experiment demonstrates the effects of the high resolution and shows further quality improvements of the PFS and higher reproducibility of extreme precipitation events associated with th

A climatological study of tropical cyclone rainfall in Vietnam.

High-temporal measurements of the stable isotope ratio (δD) of near-surface atmospheric water vapor by an Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS)-type water vapor isotope analyzer (WVIA) were performed in Sapporo from April 2009 to June 2011. The data obtained from the WVIA was corrected by comparing the δD values with those obtained from the cold trap method and subsequent cavity ring-down spectroscopy isotopic water analysis. The δD values showed a marked seasonal cycle but showed a different seasonal cycle from that of the surface air temperature. The δD values simulated by the isotopic-incorporated Global Spectral Model showed almost the same seasonal cycle as that of observed δD values, although simulated values showed about 10‰ difference from observed values in 10-month average. It is found that the monthly mean SSTmon of the nearest sea was a better predictor for δDmon than the monthly mean air temperature. Based on the data measured by the WVIA deployed on the Oshoro-Maru of Hokkaido University, from the Sea of Okhotsk to the Pacific Ocean, we confirmed that δD of water vapor generally increased with increasing SST and the highest values of δD were almost the same as those of vapor in equilibrium with ocean liquid