Balloon investigations of radiative fluxes in the free atmosphere

Summary The present research considers the vertical profiles of the radiation balance and its components for summer and autumn seasons measured by standard actinometric instruments fixed on free balloons and gives the values of radiational temperature changes in the layers of 1000 to 500 and 1000 to 20 mb.     

Photoelectric photometry of solar granulation in several regions of the continuum

Photospheric brightness fluctuations were recorded photoelectrically across a part of the sun near the center of the disk, and simultaneously for two regions of the continuous spectrum chosen at various wavelengths between λ3500 Å and λ5500 Å. The auto-correlation functions and spatial power spectra were derived for each recording, and the cross-correlation functions, spatial relative phase and coherence spectra were computed for each pair of recordings. The main results are:

1. (1)
   The cross-correlation between any two recordings obtained for various regions of the continuous spectrum, is a function of the wavelength distance Δλ between these regions. The decrease of the cross-correlation with increasing Δλ is due to the fact that separate photometric inhomogeneities radiate in limited spectral ranges.     

A SPATIAL ANALYSIS OF AGRICULTURAL INTENSITY IN A BASOTHO VILLAGE OF SOUTHERN AFRICA

The effect of distance upon agricultural production should be as apparent among primitive subsistence agriculturalists as in market-oriented societies. This analysis of yield variations among the Basotho of southern Africa attempts to determine the frictional effect of distance. The results show that distance does not explain variations in yield even when other physical factors are held constant. Perhaps such variables as household characteristics, not included in the analysis, would provide a better explanation.     

Chance coincidences and the so-called redshift systems in the absorption spectrum of PKS 0237-23

It is shown that the number of redshift systems based on Civ doublets, proposed by Borosonet al. (1978) in the absorption spectrum of the quasar PKS 0237-23, is insignificantly different from that that would be expected from chance coincidences. Consequently, these systems and theirz-values appear to be devoid of any physical significance.     

Chronology of late wisconsinan glaciation in middle North America

We propose a chronology of late Wisconsinan glacial fluctuations in middle North America, from Alberta to Wisconsin, based on radiocarbon dates derived solely from wood. Previous chronologies of the southwestern margin of the North American Continental Ice Sheet have depended to a considerable degree on radiocarbon dates from fine-grained organic sediment. This material is commonly contaminated with older carbon, resulting in chronologic confusion. By using only dates from wood, much of the confusion disappears. However, because of the scarcity of wood dates, only four of the sixteen identified fluctuations are accurately dated: an advance into Iowa about 14,000 to 13,500 BP, an advance into South Dakota and Iowa about 12,300 BP, an advance into the Lake Michigan basin about 11,700 BP, and an advance into the Lake Superior basin about 9900 BP. In addition, the beginning of late Wisconsinan glaciation, before 20,000 BP, is fairly well documented. None of the fluctuations in the western part of the region are accurately dated.     

A 1600-year history of the Labrador Current off Nova Scotia

A multicore from Emerald Basin, on the continental margin off Nova Scotia, has a modern ¹⁴C age at the top, and other ¹⁴C dates indicate a linear sedimentation rate of ~30 cm/ka to 1600 calendar years BP. This rate is great enough to record century-to-millennial scale changes in the surface and deep (~250 m) waters in the basin that are influenced by the Labrador Current. We applied five proxies for seawater temperature changes to the sediments of Emerald Basin, including the percent abundance and the oxygen isotope ratio (d ¹⁸O) of the polar planktonic foraminifer N. pachyderma (s.), the unsaturation ratio of alkenones (U ^k' ₃₇) produced by prymnesiophyte phytoplankton, and the d ¹⁸O and Mg/Ca of benthic foraminifera. All five proxies indicate the ocean warmed suddenly sometime in the past 150 years or so. The exact timing of this event is uncertain because ¹⁴C dating is inaccurate in recent centuries, but this abrupt warming probably correlates with widespread evidence for warming in the Arctic in the nineteenth century. Because the Canadian Archipelago is one of the two main sources for the Labrador Current, warming and melting of ice caps in that region may have affected Labrador Current properties. Before this recent warming, sea surface temperature was continually lower by 1–2 °C, and bottom water was colder by about 6 °C in Emerald Basin. These results suggest that there was no Medieval Warm Period in the coastal waters off Nova Scotia. Because there is also no evidence of medieval warming in the Canadian archipelago, it seems likely that coastal waters from Baffin Bay to at least as far south as Nova Scotia were continually cold for ~1500 of the past 1600 years.     

Coral recruitment onto an experimental pulverised fuel ash-concrete artificial reef

An experimental artificial reef was deployed in December 1993 at Hoi Ha Wan Marine Park, Hong Kong. This is the first study documenting natural scleractinian coral recruitment onto a stabilised pulverised fuel ash (PFA)-concrete artificial reef. Visible recruits were first recorded 9-10 months after the placement of reef blocks, i.e., in the autumn of 1994. Two scleractinians, Oulastrea crispata and Culicia japonica, were recruited. The recruit density of the former was much greater than the latter. The spatial recruitment pattern of the corals was observed to be affected by the orientation of the attaching surface. O. crispata settled predominantly on the undersides of the reef blocks. There was an edge effect on O. crispata recruitment. C. japonica, however, had a preference for exposed surfaces. O. crispata did not show a preference for block composition whereas C. japonica favoured blocks with high (75% by volume) PFA levels. This shows that PFA-concrete is a potential substratum for artificial reef construction, especially when such reefs aim at rehabilitating corals.     

Horizontal and vertical distribution of PCBs and chlorinated pesticides in sediments from Masan Bay,Korea

Horizontal and vertical distributions of organochlorine compounds (OCs) were determined in sediments from Masan Bay. The concentrations of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethanes (DDTs), HCB, hexachlorocyclohexanes (HCHs) and chlordane related compounds (CHLs) in sediments were in the range of 1.24-41.4, 0.28-89.2, 0.02-0.59, nd-1.03, and nd-2.56 ng/g, respectively. The spatial distribution of OCs showed a negative gradient from the inner of the bay to outer part of the bay, indicating that the source of OCs was probably located inside the bay. Compositional pattern of PCB congeners showed a relatively high concentration of high-chlorinated congeners in the inner part of the bay and a relatively low concentration of low-chlorinated congeners in the outer part. In sediment core from Masan Bay maximum concentrations of PCBs and DDTs are observed in the subsurface samples and correspond to an age of early 1980s and late 1960s. The concentration profiles of PCBs and DDTs in sediments of Masan Bay appear to correspond to use of PCBs and DDTs in Korea.