Innovation Design Roughness on Slope to Reduce Storms at Curved Seawall in Canggu Beach Bali

Seawall or revetment has been designed to preserve coastline erosion from waves. The seawall system or revetment could protect againstpowerful wave, reduce hydraulic power in underring material and constribute to wave reflection. The result of survey show that seawall system have to be repeatedly observed to maximize seawall action to produce a modification of seawall design.In this research, hydrodinamic seawall action is conducted by employing its curve, slope and roughness. It is investigated by using physical modeling in 2D Laboratory of Coastal Dynamics Institute Yogyakarta, Indonesia. Type of wave used in this study is Regularwave within one period of time. Wave experiment is examined in 30° of its slope, constant water depth is0.4 m and roughness on its slope using two types of sequential block position and zig zags. This research results in the significant Reflection Coefficient (Kr) which is 0.141 produced by design 1 compared to the previous research is 0.16923. Therefore, it can be concluded that design 1 is more reliable in reducing reflection wave

High-Altitude (0–100 km) Global Atmospheric Reanalysis System: Description and Application to the 2014 Austral Winter of the Deep Propagating Gravity Wave Experiment (DEEPWAVE)

A data assimilation system (DAS) is described for global atmospheric reanalysis from 0- to 100-km altitude. We apply it to the 2014 austral winter of the Deep Propagating Gravity Wave Experiment (DEEPWAVE), an international field campaign focused on gravity wave dynamics from 0 to 100 km, where an absence of reanalysis above 60 km inhibits research. Four experiments were performed from April to September 2014 and assessed for reanalysis skill above 50 km. A four-dimensional variational (4DVAR) run specified initial background error covariances statically. A hybrid-4DVAR (HYBRID) run formed background error covariances from an 80-member forecast ensemble blended with a static estimate. Each configuration was run at low and high horizontal resolution. In addition to operational observations below 50 km, each experiment assimilated 105 observations of the mesosphere and lower thermosphere (MLT) every 6 h. While all MLT reanalyses show skill relative to independent wind and temperature measurements, HYBRID outperforms 4DVAR. MLT fields at 1-h resolution (6-h analysis and 1–5-h forecasts) outperform 6-h analysis alone due to a migrating semidiurnal (SW2) tide that dominates MLT dynamics and is temporally aliased in 6-h time series. MLT reanalyses reproduce observed SW2 winds and temperatures, including phase structures and 10–15-day amplitude vacillations. The 0–100-km reanalyses reveal quasi-stationary planetary waves splitting the stratopause jet in July over New Zealand, decaying from 50 to 80 km then reintensifying above 80 km, most likely via MLT forcing due to zonal asymmetries in stratospheric gravity wave filtering.