Transmission of CO2 in the atmosphere of Venus for the spectral region near 7 microns

The transmission in the 7-μm “window” opf Venus was calculated for a 7-layer model atmosphere. The synthetic spectra show that radiation from the layer 20–30 km above the surface would reach the top of the atmosphere between 6.2 and 7.0 μm if there were no absorption besides the isotopic CO₂ bands; for the 7.0- to 8.2-μm region, the radiating level would be located 40–50 km above the surface of Venus. The brightness temperature for the entire region is 430°K; for the above two regions it is 494 and 341°K, respectively.     

Super-speed centrifugation at sea using a gimballed platform

The use of a super-speed centrifuge at sea for the recovery of suspended solids or interstitial pore fluids requires a stabilizing platform. In this report, we describe a simple platform gimball and magnetic rotor stabilizer that have been fitted to a Sorvall model SS_?3 super-speed centrifuge. In principle, any centrifuge of comparable weight (86 kg) could be easily adapted for use at sea with gimbals of similar design.The magnetic rotor coupler is designed to eliminate rotor precession when the centrifuge is operated at sea. This attachment is particularly useful when the Sorvall SS_?3 (equipped with a conventional rotor) is used to recover interstitial pore fluids.     

Random vectors and spatial analysis by geostatistics for geotechnical applications

Geostatistics is extended to the spatial analysis of vector variables by defining the estimation variance and vector variogram in terms of the magnitude of difference vectors. Many random variables in geotechnology are in vectorial terms rather than scalars, and its structural analysis requires those sample variable interpolations to construct and characterize structural models. A better local estimator will result in greater quality of input models; geostatistics can provide such estimators: kriging estimators. The efficiency of geostatistics for vector variables is demonstrated in a case study of rock joint orientations in geological formations. The positive cross-validation encourages application of geostatistics to spatial analysis of random vectors in geoscience as well as various geotechnical fields including optimum site characterization, rock mechanics for mining and civil structures, cavability analysis of block cavings, petroleum engineering, and hydrologic and hydraulic modelings.     

Venus cloud microphysics

Because sulfuric acid does not wet sulfur, composite drops in the atmosphere of Venus cannot have sulfur “cores,” but must instead have sulfur coats. Both components then communicate with the vapor phase. Drops that are fully coated with sulfur are immune to coalescence; this sets a limit to growth that may explain “Mode 3” particles. The sulfur coating is probably responsible for the anomalously low refractive indices derived from entry-probe nephelometer data. There appears to be about an order of magnitude less elemental sulfur than sulfuric acid in the clouds.     

On the cooling of the moon by solid convection

If a molten, or partially molten, lunar core exists at present, constraints would be placed on the viscosity of the solid mantle and the distribution of radioactive heat sources. Models in which the heat sources have been concentrated near the surface would rapidly solidify if the effective viscosity was equal to, or less than, 10²² cm² s⁻¹. Retention of most of the heat sources throughout the mantle would permit present day solid convection to occur without cooling the core.     

A new interpretation of the Venera 11 spectra of Venus: I. The 0.94-μm water band

Band models for CO₂ and H₂O absorption are described, and used to model the Venera 11 spectra near 1 μm. An effective-path approximation is used to allow for scattering in the clouds. The model has 10 layers and uses 211 CO₂ and 15 H₂O vibrational transitions, at 5 cm^? resolution. Within a factor of 2, a maximum absorption in the 0.94-μm H₂O band just below the clouds, corresponding to 200 ppm by volume, in agreement with V. I. Moroz, N. A. Parfen'ev, and N. F. San'ko (1979, Cosmic Res. 17, 601–614) is found. More accurate band strenghts are needed to model the bottom scale height accurately. The possibility that the 0.94-μm feature is blended with a band of some other molecule has been examined. Ten possible chemical species were examined, with negative results.     

Factors affecting outbreaks of high-density Cochlodinium polykrikoides red tides in the coastal seawaters around Yeosu and Tongyeong, Korea

Red tides caused by the dinoflagellate Cochlodinium polykrikoides occur annually in coastal waters of Korea, causing significant damage. A distinguishing characteristic of C. polykrikoides red tides is that they develop and persist in the open sea, where the water is comparatively clean with little contamination from the shore. We examined the causes of and key nutrients involved in high-density C. polykrikoides red tide outbreaks in the coastal seawaters around Yeosu and Tongyeong, Korea. High-density C. polykrikoides red tides occur in the coastal areas of Geomo Island, where freshwater flows into the sea after heavy rainfall events. Red tides are widespread in years when rainfall is heavy. The maximum concentration of C. polykrikoides and the duration of the red tides increase with increasing rainfall. Adding nitrogen and Seomjin River water to cultures of C. polykrikoides also increases biomass production and cell density of C. polykrikoides remarkably increased after heavy rainfall events. The occurrence of high concentrations of C. polykrikoides along the shores of Yeosu and Tongyeong seems to result from rainfall-initiated inflows of high concentrations of nitrate secondarily, after a conducive physical and chemical open-water environment has been established for C. polykrikoides to spread initially.     

A robust sequential CO2 emissions strategy based on optimal control of atmospheric CO2 concentrations

This paper formally introduces the concept of mitigation as a stochastic control problem. This is illustrated by applying a digital state variable feedback control approach known as Non-Minimum State Space (NMSS) control to the problem of specifying carbon emissions to control atmospheric CO₂ concentrations in the presence of uncertainty. It is shown that the control approach naturally lends itself to integrating both anticipatory and reflexive mitigation strategies within a single unified framework. The framework explicitly considers the closed-loop nature of climate mitigation, and employs a policy orientated optimisation procedure to specify the properties of this closed-loop system. The product of this exercise is a control law that is suitably conditioned to regulate atmospheric CO₂ concentrations through assimilating online information within a 25-year review cycle framework. It is shown that the optimal control law is also robust when faced with significant levels of uncertainty about the functioning of the global carbon cycle.