Turbulent Flux Observations at the Tip of a Narrow Cape on Miyako Island in Japan's Southwestern Islands

Abstract

Air-sea fluxes were observed to elucidate the lower boundary conditions in the development of an atmospheric boundary layer over sea from 14 to 27 August 2002. Fluxes were observed at the tip of a narrow cape on Miyako Island, in Japan's Southwestern Islands. Flux measurements and turbulence properties were clearly divided by fetch condition or wind direction. Analysis of the footprint area and homogeneity indicated that air-sea fluxes over an upwind sea surface were observed in cases of approximately 30% for all observation periods. The bulk transfer (BT), eddy covariance (EC), and variance (VA) methods were used to evaluate air-sea fluxes. The general features of the estimated fluxes were similar. Averaged sensible heat flux of approximately 6 W m −2 was obtained by all three methods, and the latent heat fluxes were 92, 60, and 71 W m −2 by the BT, EC, and VA methods, respectively. Daily mean net radiation input R NET was 223 W m −2 . The sea surface was a large energy sink during the observation period.

Spatial Heterogeneity of Air–Sea Energy Fluxes over a Coral Reef—Heron Reef, Australia

“…, which was generally in agreement with summertime Q* reported for coral reefs (Kjerfve 1978;Tanaka et al 2008). The mean Q H and Q E over the reef flat for the three observation periods ranged from 6.7 to 16.4 W m 22 and from 84.9 to 138.4 W m 22 , respectively.…”

“…Net radiation (the sum of incoming and outgoing shortand longwave radiation) over coral reefs is typically lower than over the surrounding tropical ocean, because of the higher albedo (light scattering) of the reef surface, typically with a higher proportion of Q* being absorbed into the water column Tanaka et al 2008). Consequently, coral reefs are subject to enhanced heating, due to the lower thermal capacity of the shallower water column relative to the surrounding ocean (Nihei et al 2002).…”

“…This highlighted wind speed and the air-reef-water temperature difference as key controls of the turbulent fluxes over coral reefs. Tanaka et al (2008) measured radiation and turbulent fluxes directly with a mast-mounted eddy covariance (EC) system, downwind of a coral reef in late summer. They found the mean Q H to be small at 6 W m…”

Structure of Convective Circulation in the Atmospheric Boundary Layer over the Northwestern Pacific Ocean under a Subtropical High

“…1). Also, flux observations were carried out at the tip of Cape 125.26 E) on Miyako Island, as shown in Tanaka et al (2008). The intensive observation period (IOP) started at 00 UTC (09 JST) on August 20, and continued to 00 UTC on August 27, 2002.…”

“…1) shown in Tanaka et al (2008). The observed SST at Cape Nishi-Henna at the start time of the simulation was not used, because it had significant diurnal variation during the observation period; that is, the SST observation point would be close to the land.…”