Measurement of Planetary Boundary Layer Winds with Scanning Doppler Lidar

The accurate measurement of wind profiles in the planetary boundary layer (PBL) is important not only for numerical weather prediction, but also for air quality modeling. Two wind retrieval methods using scanning Doppler light detection and ranging (lidar) measurements were compared and validated with simultaneous radiosonde soundings. A comparison with 17 radiosonde sounding profiles showed that the sine-fitting method was able to retrieve a larger number of data points, but the singular value decomposition method showed significantly smaller bias (0.57 m s(-1)) and root-mean-square error (1.75 m s(-1)) with radiosonde soundings. Increasing the averaging time interval of radial velocity for obtaining velocity azimuth display scans to 15 min resulted in better agreement with radiosonde soundings due to the signal averaging effect on noise. Simultaneous measurements from collocated wind Doppler lidar and aerosol Mie-scattering lidar revealed the temporal evolution of PBL winds and the vertical distribution of aerosols within the PBL

Role of S5b/PSMD5 in Proteasome Inhibition Caused by TNF-α/NFκB in Higher Eukaryotes

SummaryThe ubiquitin-proteasome system is essential for maintaining protein homeostasis. However, proteasome dysregulation in chronic diseases is poorly understood. Through genome-wide cell-based screening using 5,500 cDNAs, a signaling pathway leading to NFκB activation was selected as an inhibitor of 26S proteasome. TNF-α increased S5b (HGNC symbol PSMD5; hereafter S5b/PSMD5) expression via NFκB, and the surplus S5b/PSMD5 directly inhibited 26S proteasome assembly and activity. Downregulation of S5b/PSMD5 abolished TNF-α-induced proteasome inhibition. TNF-α enhanced the interaction of S5b/PSMD5 with S7/PSMC2 in nonproteasome complexes, and interference of this interaction rescued TNF-α-induced proteasome inhibition. Transgenic mice expressing S5b/PSMD5 exhibited a reduced life span and premature onset of aging-related phenotypes, including reduced proteasome activity in their tissues. Conversely, S5b/PSMD5 deficiency in Drosophila melanogaster ameliorated the tau rough eye phenotype, enhanced proteasome activity, and extended the life span of tau flies. These results reveal the critical role of S5b/PSMD5 in negative regulation of proteasome by TNF-α/NFκB and provide insights into proteasome inhibition in human disease

Impacts of Detailed Land-Use Types and Urban Heat in an Urban Canopy Model on Local Meteorology and Ozone Levels for Air Quality Modeling in a Coastal City, Korea

An urban canopy model (UCM), with detailed urban land-use and anthropogenic heat information, is required to reproduce and understand the urbanization process and its impact on regional climate and urban air quality. This study investigates the UCM impact on simulated meteorology and surface ozone in the coastal city of Busan using the WRF-SMOKE-CMAQ model coupled with (UCM case), and without the UCM (NOUCM case). The UCM and NOUCM case results suggest that UCM case generally produces warmer temperatures and deeper planetary boundary layer (PBL) heights, especially in the early morning and night time, than the NOUCM case. Owing to urban heating and enhanced turbulent mixing incorporation in the center of the city, the sea breeze in the UCM case tends to penetrate faster and more strongly than in the NOUCM case. After sea breeze arrival at the urban center, the urban heat island effect prevents its penetration further inland. In the UCM case in the late afternoon, local meteorological changes induce remarkable increases in simulated O3 concentrations over the downwind (up to 17.1 ppb) and downtown (up to 10.6 ppb) areas. This is probably due to an increase in temperature in the urban areas and the wind convergence zone movement due to the sea breeze interaction and offshore flows. The increase in O3 concentration in the late afternoon results in the model bias reduction under previously underestimated O3 conditions due to high NOx emissions. The simulated O3 concentrations in the UCM case are more similar to the observed O3 concentrations compared to those of the NOUCM case

Spatiotemporal variability in ocean-driven basal melting of cold-water cavity ice shelf in Terra Nova Bay, East Antarctica: roles of tide and cavity geometry

Mass loss from ice shelves occurs through ocean-driven melting regulated by dynamic and thermodynamic processes in sub-ice shelf cavities. However, the understanding of these oceanic processes is quite limited because of the scant observations under ice shelves. Here, a regional coupled sea-ice/ocean model that includes physical interactions between the ocean and the ice shelf is used as an alternative tool for exploring ocean-driven melting beneath the Nansen Ice Shelf (NIS) which is a cold-water cavity ice shelf located beside Terra Nova Bay (TNB) in East Antarctica. For the first time, this study identifies the spatiotemporal variability signatures for different modes of ocean-driven melting at the base of NIS. In February (austral summer), basal melting substantially increases where the ice shelf draft is relatively small in the vicinity of the ice shelf front, contributing 78% of the total NIS melting rate. As the dominant source of NIS mass loss, this melting is driven by tide-induced turbulent mixing along the sloping ice shelf base and summer warm surface water intruding beneath and reaching the shallow parts of the ice shelf. In contrast, the NIS has relatively high basal melting rates near the grounding line in September (austral winter) primarily because of the intrusion of high-salinity shelf water produced by polynya activity in TNB that flows into the cavity beneath NIS toward the deep grounding line. Of the total melting rate of NIS in winter, 36% comes from regions near the grounding line. In addition, the contributions of tides and realistic cavity geometry to NIS basal melting are identified by conducting sensitivity experiments. Tidal effects increase the melting of NIS throughout the year, particularly contributing as much as 30% to the areas of ice draft shallower than 200 m in summer. Sensitivity results for uncertainty in cavity geometry show that spurious vertical mixing can be locally induced and enhanced by interaction between tides and the unrealistic topography, resulting in excessive basal melting near the NIS frontal band. The sensitivity experiments have shown that tides and realistic cavity geometry bring a significant improvement in the estimation of basal melt rates through a numerical model

Analysis of Long-Range Transport of Carbon Dioxide and Its High Concentration Events over East Asian Region Using GOSAT Data and GEOS-Chem Modeling

This study aims to evaluate the long-range transport of CO2 in East Asian region, using concentration data in a surface measurement site (Gosan Station), column averaged concentration data of satellite-borne instrument (GOSAT), and GEOS-Chem modeling results for the period of June 2009 to May 2011. We perform a validation of the data from GOSAT and GEOS-Chem with total column observations (TCCON). The analysis of the long-range transport and high concentration (HC) events using surface/satellite observations and modeling results is conducted. During the HC events, the concentrations in CO2 and other air pollutants such as SO2 and CO are higher than that of all episodes. It means that CO2, known as a globally well-mixed gas, may also act as a fingerprint of human activity with unique regional characteristics like other air pollutants. This comprehensive analysis, in particular with GOSAT CO2 observation data, shows that CO2 plume with high concentration can be long-range transported with 1-2 days' duration with regional scale. We can find out with GEOS-Chem tagging simulation that more than 45% of the elevated CO2 concentration over central/eastern China, Korea, and Japan on high concentration days can be explained by emission sources of East Asia mainland.open0