Maximum In Late Winter Research Articles

The phytal animals on the thalli of Sargassum serratifolium in the Sargassum region, with reference to their seasonal fluctuations

In the Sargassum region on the coast of Mukaishima, in the Inland Sea of Japan, the phytal animals living on Sargassum serratifolium, and the alga itself as a habitat for phytal animals, were studied from August, 1966 to August, 1968. The standing crop of Sargassum/m2 bottom was 4.93 kg/m2 (March, 1967) and 3.53 kg/m2 (February, 1968) in the most luxuriant season, and 0.4 to 0.5 kg/m2 (July, 1967 and 1968) in the off-season. The individual number of phytal animals per mean plant, without sessile fauna, reached a maximum in late winter and early spring (about 130,000 in 1967, 266,000 in 1968) when Sargassum was luxuriant, and a minimum in summer (about 15,000 in both years) when Sargassum was declining. Among the phytal animals, benthonic copepods (Harpacticoida) were very abundant in most seasons. Their dominance decreased in spring, whilst nematode dominance increased. It appears that such seasonal changes are closely related to the standing crop of S. serratifolium. Fluctuations in numbers of most groups of the meiofauna of phytal animals, such as foraminiferans, ostracods, isopods, amphipods, copepods, tanaids and nematodes, are connected with changes in the standing Sargassum crop. Seasonal fluctuations of some groups, such as echinoderms, actinians, mysids and decapod crustaceans (macrofauna), were, however, independent of Sargassum crop variations. The individual number of phytal animals/m2 bottom in the Sargassum region were compared with findings of previous studies in other habitats, such as naked sandy and mud bottoms.

Latitude distribution of ozone at high altitudes, deduced from a satellite measurement of the Earth's radiance at 2840 A

The radiance of the earth's daylit atmosphere at 2840 A has been measured with a satellite-borne radiometer as a function of latitude, along the 2 o'clock meridian, and as a function of angle of insolation. The data are compared with the expected radiances calculated using three different ozone distributions, the Altshuler and Elterman models and the 1949 NRL measurement (corrected) of Johnson et al. The Johnson data lead to the closest agreement, but the radiance is still about 50% higher than our measurements—implying a total ozone concentration above 35 km about twice that of Johnson's. Using the relation between radiance and ozone concentration, the data are analyzed to give the latitude distribution of the high-altitude (>35 km) ozone. This analysis shows that the seasonal variation of the high-altitude ozone appears to be about 6 months out of phase with the well-known seasonal variation near the peak of the ozone profile (maximum in late winter and minimum in late summer). The spectral distribution of the ultraviolet radiance calculated by a number of authors, along with the present measurement and the data of other experimenters, are summarized and compared.