Myung-Sook Park

Dietary supplementation of (+)-catechin protects against UVB-induced skin damage by modulating antioxidant enzyme activities

Purpose: The aim of this study was to investigate the effects of dietary supplementation with (+)‐catechin on cutaneous antioxidant enzymes and the skin damage caused by UVB irradiation.

Latent Heating and Cooling Rates in Developing and Nondeveloping Tropical Disturbances during TCS-08: TRMM PR versus ELDORA Retrievals*

AbstractUnique sets of Electra Doppler Radar (ELDORA) observations in both developing and nondeveloping tropical disturbances in the western North Pacific are used to retrieve latent heating and cooling rates. During the reintensification of Sinlaku, maximum heating rates of about 80 K h−1 are diagnosed in the upper troposphere in the region of a strong updraft and maximum cooling rates of about −45 K h−1 are diagnosed in the lower troposphere in the region of a strong convective-scale downdraft. The southern convective burst in the pre-Nuri mission had a lower-tropospheric maximum in latent heating that was a more favorable condition for tropical cyclone formation than was the upper-tropospheric maximum in heating and the lower-tropospheric maximum in cooling in the northern convective burst. Two nondeveloping tropical disturbances had deeper layers of more uniform heating and of cooling rates, and some evidence of more shallow cloud tops, that distinguished them from the developing cases.Although the Sh...

Tropical Cyclone Mekkhala’s (2008) Formation over the South China Sea: Mesoscale, Synoptic-Scale, and Large-Scale Contributions

AbstractTropical cyclone formation close to the coastline of the Asian continent presents a significant threat to heavily populated coastal countries. A case study of Tropical Storm Mekkhala (2008) that developed off the coast of Vietnam is presented using the high-resolution analyses of the European Centre for Medium-Range Weather Forecasts/Year of Tropical Convection and multiple satellite observations. The authors have analyzed contributions to the formation from large-scale intraseasonal variability, synoptic perturbations, and mesoscale convective systems (MCSs). Within a large-scale westerly wind burst (WWB) associated with the Madden–Julian oscillation (MJO), synoptic perturbations generated by two preceding tropical cyclones initiated the pre-Mekkhala low-level vortex over the Philippine Sea. Typhoon Hagupit produced a synoptic-scale wave train that contributed to the development of Jangmi, but likely suppressed the Mekkhala formation. The low-level vortex of the pre-Mekkhala disturbance was then ...

Latent Heating and Cooling Rates in Developing and Nondeveloping Tropical Disturbances during TCS-08: Radar-Equivalent Retrievals from Mesoscale Numerical Models and ELDORA*

AbstractLatent heating and cooling rates have a critical role in predicting tropical cyclone formation and intensification. In a prior study, Park and Elsberry estimated the latent heating and cooling rates from aircraft Doppler radar [Electra Doppler Radar (ELDORA)] observations for two developing and two nondeveloping tropical disturbances during the Tropical Cyclone Structure 2008 (TCS-08) field experiment. In this study, equivalent retrievals of heating rates from two mesoscale models with 1-km resolution are calculated with the same radar thermodynamic retrieval. Contoured frequency altitude diagrams and vertical profiles of the net latent heating rates from the model are compared with the ELDORA-retrieved rates in similar cloud-cluster regions relative to the center of circulation.In both the developing and nondeveloping cases, the radar-equivalent retrievals from the two models tend to overestimate heating for less frequently occurring, intense convective cells that contribute to positive vorticity...

Retrieval of Outgoing Longwave Radiation from COMS Narrowband Infrared Imagery

Hourly outgoing longwave radiation (OLR) from the geostationary satellite Communication Oceanography Meteorological Satellite (COMS) has been retrieved since June 2010. The COMS OLR retrieval algorithms are based on regression analyses of radiative transfer simulations for spectral functions of COMS infrared channels. This study documents the accuracies of OLRs for future climate applications by making an intercomparison of four OLRs from one single-channel algorithm (OLR12.0 using the 12.0 μm channel) and three multiple-channel algorithms (OLR10.8+12.0 using the 10.8 and 12.0 μm channels; OLR6.7+10.8 using the 6.7 and 10.8 μm channels; and OLRAll using the 6.7, 10.8, and 12.0 μm channels). The COMS OLRs from these algorithms were validated with direct measurements of OLR from a broadband radiometer of the Clouds and Earth’s Radiant Energy System (CERES) over the full COMS field of view [roughly (50°S–50°N, 70°–170°E)] during April 2011.Validation results show that the root-mean-square errors of COMS OLRs are 5–7 W m−2, which indicates good agreement with CERES OLR over the vast domain. OLR6.7+10.8 and OLRAll have much smaller errors (∼6 W m−2) than OLR12.0 and OLR10.8+12.0 (∼8 W m−2). Moreover, the small errors of OLR6.7+10.8 and OLRAll are systematic and can be readily reduced through additional mean bias correction and/or radiance calibration. These results indicate a noteworthy role of the 6.7 μm water vapor absorption channel in improving the accuracy of the OLRs. The dependence of the accuracy of COMS OLRs on various surface, atmospheric, and observational conditions is also discussed.

Automated Information Retrieval for Hazard Identification in Construction Sites

The repetitive occurrence of similar accident in construction disasters is one of the prevalent features. Similar accident cases provide direct information for determining the risk of scheduled activities and planning safety countermeasure. Researchers have developed many systems in order to retrieve and use past accident cases. Although the developed systems have a clear and limited target, most of them were developed under a retrieval methods based on ad-hoc systems which can cause inconvenience for users in using the retrieval system. To overcome these limitations, this study proposes an automated information retrieval system that can search for and provide similar accident cases. The retrieval system extracts building information modeling objects and composes a query set by combining BIM objects with a project management information system. Based on the results of this study, the users can excessively reduce query generation. Furthermore, they can easily avoid risks by receiving similar past accident cases that can happen while they work.

Variation of the Tropical Cyclone Season Start in the Western North Pacific

AbstractThe variation of the tropical cyclone (TC) season in the western North Pacific (WNP) was analyzed based on the percentiles of annual TC formation dates. The results show that the length of the TC season is highly modulated by the TC season’s start rather than its end. The start of the TC season in the WNP has large interannual variation that is closely associated with the variation of the sea surface temperature (SST) in the Indian Ocean (IO) and the central-eastern Pacific (CEP). When the SSTs of the IO and CEP are warm (cold) in the preceding winter, anomalous high (low) pressure and anticyclonic (cyclonic) circulation are induced around the WNP TC basin the following spring, resulting in a late (early) start of the TC season. These results suggest that a strong El Nino in the preceding winter significantly delays the TC season start in the following year.

Comments on “Multiscale Structure and Evolution of Hurricane Earl (2010) during Rapid Intensification”

AbstractThis comment addresses the Tropical Storm (TS) Earl upper-level vortex structure changes during a critical stage leading to the onset of rapid intensification as described by Rogers et al. Whereas the first NOAA WP-3D mission in TS Earl provided evidence of a shallow, broad vortex structure, the second WP-3D mission just 12 h later documented a deep, vertically stacked vortex undergoing rapid intensification. The authors attribute this vortex structure change to vertical alignment processes between the low-level Earl vortex and an upper-tropospheric mesoscale vortex about 50 km to the east in the mission 1 analyses.An alternate environmental control explanation is proposed in which a special kind of upper-tropospheric vertical wind shear (VWS) associated with the outflow of Hurricane Danielle to the northwest of TS Earl is the primary factor. Two estimates of the vertical wind shear changes are interpreted relative to the diurnal convective maximum/minimum to explain how the shallow vortex during ...

Land-Based Convection Effects on Formation of Tropical Cyclone Mekkhala (2008)

AbstractThe effects of land-based convection on the formation of Tropical Storm Mekkhala (2008) off the west coast of the Philippines are investigated using the Weather Research and Forecasting Model with 4-km horizontal grid spacing. Five simulations with Thompson microphysics are utilized to select the control-land experiment that reasonably replicates the observed sea level pressure evolution. To demonstrate the contribution of the land-based convection, sensitivity experiments are performed by changing the land of the northern Philippines to water, and all five of these no-land experiments fail to develop Mekkhala.The Mekkhala tropical depression develops when an intense, well-organized land-based mesoscale convective system moves offshore from Luzon and interacts with an oceanic mesoscale system embedded in a strong monsoon westerly flow. Because of this interaction, a midtropospheric mesoscale convective vortex (MCV) organizes offshore from Luzon, where monsoon convection continues to contribute to ...

Multiday evolution of convective bursts during western North Pacific tropical cyclone development and nondevelopment using geostationary satellite measurements

Tropical cyclones (TCs) develop through latent heating from a series of deep convection. To investigate the evolution of diurnal convective burst (CB) activities prior to TC formation, we analyzed 463 tropical disturbances that developed (80) or not-developed (383) into TCs over the western North Pacific during the 2007 − 2009 period. Geostationary satellite data allowed defining deep convection where infrared (IR) brightness temperature is lower than that of water vapor (WV). Diurnal expansions from time series of IR minus WV < 0 areas near disturbance vortex centers for five days are defined as CB events. Combined analysis with the Modern Era Retrospective-Analysis shows that the multi-day convective-environmental evolution for TC formation is entirely different from non-formation processes in terms of the occurrence of two consecutive diurnal CB events. Multi-day CBs (mCB) are observed in 67.5% of the 80 TC formation cases and in 13.8% of the 383 non-formation cases. Intensities of the mid-to-low tropospheric relative vorticity of these two groups are comparable on four to five days prior to TC formation. However, vorticity intensification is weak for non-developing disturbances in environments of strong vertical wind shear; these disturbances eventually decay. The vorticity of developing disturbances continuously intensifies to TC strengths. Remaining 32.5% of the TC cases without mCB show weaker initial vorticity, but rapidly intensification over three day periods before TC formation. The present results reveal that mCB is a common feature in pre-TC stages, and large-scale environments of weak vertical wind shear are critical for the formation of TC-strength circulations.