博士 / 國立中興大學 / 環境工程學系所 / 97 / The observations were conducted on a research vessel in summers of 2004, 2006, 2007 and 2008, includeing meteorological variables, surface energy components and CO2 fluxes. This is the pioneering for being set up eddy covariance system on a research vessel with CO2 flux ovservation in domestic. Several C++ programs were wrote for raw data processes, including CTD data arrangement, cruise routes of R/V OR1, screening mechanism of albedo and air pollutant, sea correction, sonic anemometer tilt correction and WPL correction. In order to avoid interference from R/V OR1, the terrestrial longwave radiation was faced vertical plane anf half anti-dazzling reflect solar radiation were faced downward. The CO2 fluxes after WPL correction would be changed from down to up, when CO2 fluxes were less than -5x10-2 mg m-2 s-1. The observed latent heat flux and sensible heat flux are over-estimated even though wind speed is not high. It could not be avoid interference for R/V OR1 itself, caused and over-estimated. In addition, measurements of meteorological variables and surface energy components over the South China Sea (SCS) are compared with the NCEP-DOE AMIP-II reanalysis (NCEP2). The middle part of SCS was CO2 sink, which lower CO2 concentration in air was caused by negative CO2 flux. The southern and northern part of SCS was CO2 source, which higher CO2 concentration in air was caused by positive CO2 flux during OR1-837 cruise. The average pCO2 concentration in air is 397 ppm and in water is 378 ppm during OR1-861 (2008) cruise. The average pCO2 in air > in water, most of CO2 flux is negative by Wanninhof’s method.
In addition, a one-column ocean model is used to simulate surface energy components and upper-level water temperatures (at 4 m and 10 m depths). The simulated upper-level water temperatures agree well with the observations during the first two cruises (OR1-728, OR1-802) with a root-mean-square difference (RMSD) smaller than 0.4 K. The observations and the simulations show that the solar radiation (with a mean of ~200 W m-2) is stronger than the latent heat flux (~160 W m-2), and the latent heat flux is stronger than the sensible heat flux (~10 W m-2) during both periods. Nonetheless, the magnitude of variability in heat flux caused by the sporadic wind is not seen in the reanalysis, it appears in the turbulent heat flux simulated by the model. The major differences between the model estimate and the NCEP2 reanalysis are the value of emissivity and the inclusion of diurnal cycles in key variables, with the value of NCEP2 for emissivity as 1. The emissivity of this part of ocean is observed to be 0.96 with albedo at 0.07-0.08. The wind directions are consistency between NCEP and sea correction data in OR1-837 (2007) and OR1-873 (2008) cruises.
It is well known that skin sea surface temperature (SSST) is different from bulk sea surface temperature (BSST) by about a few tenths of a degree Celsius. Nonetheless, it is not well known how large the error is associated with dry deposition (or uptake) estimation by using BSST. This study tries to conduct such an evaluation. For a case study using the data observed from a research ship that cruised over the South China Sea in the summers of 2004 and 2006, it has been found that when a warm layer occurred, the deposition velocities using BSST were underestimated within the range of 0.8 – 4.3 %, and surface ground heat flux was overestimated by 21 W m-2. In contrast, under cool-skin only conditions, the deposition velocities using BSST were overestimated within the range of 0.5 – 2.0 %, varying with pollutants and surface ground heat flux was underestimated by 21 W m-2.
Keywords: South China Sea; R/V OR1; deposition resistance; Henry constant; chemical enhancement factor; warm layer; eddy covariance system, diurnal cycle, sea correction; sonic anemometer tilt correction; WPL correction.
| Identifer | oai:union.ndltd.org:TW/097NCHU5087054 |
| Creators | Yung-Yao Lan, 藍詠耀 |
| Contributors | Ben-Jei Tsuang, 莊秉潔 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | en_US |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 292 |
Page generated in 0.0154 seconds