Long-term variation of solar UVB (290–330 nm) observed at the earth's surface

During solar cycle 21 (1976–86), the primary solar irradiance at 300 nm was steady during 1980–82 and thereafter decreased until 1986 by only 2–3%. The stratospheric ozone in middle latitudes had a QBO of 3–4% in this interval but the long-term ozone trend was less than 3% per decade, which could result in a UVB increase of only 5–6% per decade. Thus, the combined effect of changes in primary solar irradiance and ozone changes could be an increase of 5–6% in UVB, observed at ground during 1977–81 and a steady level during 1981–86. During 1976–86, the average cloudiness changed by less than 5% indicating UVB changes of 5% or less on this count. The aerosol level was almost constant during 1976–82 and increased abruptly in 1982 due to the E1 Chichon eruption and decayed slowly unitl 1986. Thus, due to aerosols only, the UVB was expected to be constant during 1976–82, to decrease sharply in 1982 and to recoup slowly thereafter.Measurements of clear-sky solar UVB at ground made at Jungfraujoch (Swiss Alps, 47°N, 8°E) during 1981–89 and at Rockville, USA (39°N, 77°W) were not comparable between themselves and did not follow the above expected patterns. Neither did the all-day R-B meter UVB measurements at Philadelphia, USA (40°N, 75°W) and Minneapolis, USA (45°N, 93°W). We suspect that some of these measurements are erroneous. This needs further detailed scrutiny.     

Gnevyshev Peaks in the CME Average Speeds in Cycle 23

Sunspots have a major 11-year cycle, but the three to four years near the maximum may show two or more peaks called Gnevyshev peaks. Earlier, it was reported that in Solar Cycle 23, the double peak in sunspot numbers was reflected in the electromagnetic radiations and coronal mass ejection (CME) frequencies in the solar atmosphere, but with phase differences. In this article, it is shown that the average CME speeds also show Gnevyshev peaks but with phase differences.     

GeoPT2. International Proficiency Test for Analytical Geochemistry Laboratories - Report on Round 2

Results from sixty laboratories participating in GeoPT2, the international proficiency testing programme for analytical geochemistry laboratories, are reported. Compared with 71.3% in the last round, 74.6% of the reported data complied with the laboratories' selected fitness for purpose criteria.     

Genetic differentiation ofNiphargus rhenorhodanensis (Amphipoda) from interstitial and karst environments

Electrophoretic variation in proteins encoded by seven presumptive gene loci was analyzed in four populations of the stygobiont amphipodNiphargus rhenorhodanensis. The four populations occur in different habitats, including one in drainage canals, another from sediments of the Ain River, a tributary of the Rhône River, and the remaining two occur in a karstic massif (Dorvan, Ain, France) in the epikarstic and at the base level of the massif, respectively. Six of the seven loci were polymorphic within or among populations, with as many as three electromorphs segregating at the most variable loci. Significant deficiencies in the frequency of heterozygotes were common. Genetic divergence between the two populations of the Dorvan Massif and between the two of the Ain River (forest and sediment habitats) was large. This was highly unexpected, particularly in the case of the two hydrologically connected populations of the Dorvan Massif. It is suggested that either low migration rates or the presence of ecological barriers to gene flow may result in strong genetic differention among local populations ofNiphargus.