Winter Amounts Research Articles

Spatial distribution of seasonal rainfall trends in a western Mediterranean area

AbstractChanges in seasonal patterns of rainfall are key ecological factors. The definition of the spatial scale on which these changes can occur is particularly relevant in Mediterranean areas, where problems related to the variability of the pluviometric regime vary from one place to another. The region of Valencia is a good example of this kind of variability in rainfall regimes. To study changes in seasonal means and variability, we have applied non‐parametric (Spearman test) and parametric techniques (linear model) to data from 97 pluviometric stations during the World Meteorological Organization (WMO) normal period, 1961–1990. Special emphasis has been placed on the analysis of the spatial pattern of trends in means and variability. For this purpose, we have used a modified version of the Cramér–von Mises test in order to define subregional areas with similar rainfall evolution. Our results show a high spatial heterogeneity in rainfall evolution. The striking feature is the progressive dryness in the autumn season accompanied by an increase in interannual variability. Increases in winter and summer interannual variability, and decreases in rainfall amounts in winter are dominant too. We discuss these results in relation to rainfall generation mechanisms and their ecological implications. Copyright © 2001 Royal Meteorological Society

082 Identification and Partial Characterization of Seasonally Regulated Proteins in Apple Bark Tissues

During autumnal leaf senescence, leaf nitrogen is translocated to bark and root tissues for storage. By definition, proteins that accumulate in large amounts in winter and are absent in summer are called storage proteins. These storage proteins are believed to play an important role in spring growth and helping trees to tolerate and/or recover from both abiotic and biotic stress. Little knowledge exists regarding storage proteins in apple, their physiological function, or how management practices impact them. Our objectives in this research was to characterize seasonally regulated proteins in apple, develop knowledge about their physiological function, and determine how they are affected by management practices. Results of the first-year studies have identified four major proteins that exhibit a seasonal pattern of accumulation in bark tissues of apple. One of these is a pathogenesis-related protein, meaning that it plays a role in disease resistance. Another of these proteins is a stress-related protein important in the use of carbohydrates under stress conditions. A third protein is a vegetative storage protein serving as a reserve for nitrogen. The last protein has not been completely identified. Greatest seasonal fluctuation of these proteins occurred in current season and 1-year-old bark tissues. Experimental studies that achieved varying levels of nitrogen in shoot tissues of young Fuji apple trees were examined for the effect on the accumulation of these proteins. Results indicated that despite a significant increase in total nitrogen, increases in the accumulation of these proteins were only slight. Instead, it appears that most of the nitrogen was present as free amino acids rather than stable proteins. These data indicate that more knowledge is required to determine the benefits and feasibility of elevating the levels of specific proteins in dormant apple trees or trying to manipulate the type of amino acids that accumulate.

Conservation of wild reindeer in Kamchatka

The wild reindeer of Kamchatka were never numerous and probably did not exceed 15 000 in number because of the restricted amount of winter and summer range, and the characteristically deep snow of the peninsula. Before I960, biologists believed there was one population with three major wintering areas. The inaccessibility of the interior of the peninsula provided natural protection for wild reindeer and other wildlife. After I960, the road system was expanded for the benefit of the logging and mining industries, and poorly regulated commercial hunting of wild reindeer expanded. The wild reindeer population declined rapidly, and became fragmented into 3 herds by the early 1970s. The herds in southern and northeastern Kamchatka were reduced to a few hundred animals, but the herd in eastern Kamchatka that was largely protected by the federal Kronotskii Biosphere Reserve recovered. Poorly regulated hunting and competition with domestic reindeer continue to be the major conservation issues facing wild reindeer in Kamchatka.

Accounting for clouds in sea ice models

Over sea ice in winter, the clouds, the surface-layer air temperature, and the long-wave radiation are closely coupled. Here we use archived data from the Russian North Pole (NP) drifting stations and our own data from Ice Station Weddell (ISW) to investigate this coupling. Both Arctic and Antarctic distributions of total cloud amount are U-shaped: that is, observed cloud amounts are typically either 0–2 tenths or 8–10 tenths in the polar regions. We fitted these data with beta distributions and, using roughly 70 station-years of observations from the NP stations, compute fitting parameters for each winter month. Although we find that surface-layer air temperature and total cloud amount are correlated, it is not straightforward to predict one from the other because temperature is normally distributed while cloud amount has a U-shaped distribution. Nevertheless, we develop a statistical algorithm that can predict total cloud amount in winter from surface-layer temperature alone and, as required, produces a distribution of cloud amounts that is U-shaped. Because sea ice models usually need cloud data to estimate incoming long-wave radiation, this algorithm may be useful for estimating cloud amounts and, thus, for computing the surface heat budget where no visual cloud observations are available but temperature is measured — from the Arctic buoy network or from automatic weather stations, for example. The incoming long-wave radiation in sea ice models is generally highly parameterized. We evaluate five common parameterizations using data from NP-4, NP-25, and ISW. The formula for estimating incoming long-wave radiation that König-Langlo and Augstein developed using both Arctic and Antarctic data has the best properties but does depend nonlinearly on total cloud amount. This nonlinearity is crucial since cloud distributions are U-shaped while common sources of cloud data tabulate only mean monthly values. Lastly, we therefore use a one-dimensional sea ice model to investigate how methods of averaging cloud amounts affect predicted sea ice thickness in the context of the five long-wave radiation parameterizations. Here, too, König-Langlo and Augstein's formula performs best, and using daily averaged cloud data yields more realistic results than using monthly averaged cloud data that have been interpolated to daily values.

Physical mechanism and statistics of occurrence of an additional layer in the equatorial ionosphere

A physical mechanism and the location and latitudinal extent of an additional layer, called the F3 layer, that exists in the equatorial ionosphere are presented. A statistical analysis of the occurrence of the layer recorded at the equatorial station Fortaleza (4°S, 38°W; dip 9°S) in Brazil is also presented. The F3 layer forms during the morning‐noon period in that equatorial region where the combined effect of the upward E×B drift and neutral wind provides a vertically upward plasma drift velocity at altitudes near and above the F2 peak. This velocity causes the F2 peak to drift upward and form the F3 layer while the normal F2 layer develops at lower altitudes through the usual photochemical and dynamical effects of the equatorial region. The peak electron density of the F3 layer can exceed that of the F2 layer. The F3 layer is predicted to be distinct on the summer side of the geomagnetic equator during periods of low solar activity and to become less distinct as the solar activity increases. Ionograms recorded at Fortaleza in 1995 show the existence of an F3 layer on 49% of the days, with the occurrence being most frequent (75%) and distinct in summer, as expected. During summer the layer occurs earlier and lasts longer compared to the other seasons; on the average, the layer occurs at around 0930 LT and lasts for about 3 hours. The altitude of the layer is also high in summer, with the mean peak virtual height being about 570 km. However, the critical frequency of the layer (f0F3) exceeds that of the F2 layer (f0f2) by the largest amounts in winter and equinox; f0F3 exceeds f0F2 by a yearly average of about 1.3 MHz.

MU radar observations of H+ ions in the topside ionosphere

We report the detection of H+ ions in the topside ionosphere above the middle and upper atmosphere (MU) radar in Japan, the first such detection by a mesosphere‐stratosphere‐troposphere radar extended to perform as an incoherent scatter radar. Owing to the very limited signal‐to‐noise ratios of ∼1% achievable in the topside ionosphere with this radar, long integration times of 45 min and statistical analysis of 10 years of data are employed to yield useful results. This sensitivity restriction limits the top altitude of observation to only ∼400 km during solar‐minimum winter but up to ∼650 km during solar‐maximum summer. These measurements are possible only at night, when we may assume that the electrons and ions have the same temperature. While the data scatter is large, climatological averages constructed for various solar‐activity, seasonal, and magnetic activity cases show less than ∼5% H+ at most under conditions of detect ability, although it is exactly those conditions of undetectability which are expected to correspond to the highest proportions of H+. At solar maximum we see no detectable amounts of H+ up to 650 km altitude, except perhaps for a faint amount in winter. At solar minimum the data are good up to ∼550 km during summer and equinox but to only ∼400 km during winter. The H+ profiles for solar‐minimum summer and equinox closely resemble each other and reach ∼5% at 550 km altitude. We see no clearly discernible H+ in winter up to our 400 km altitude limit of detectability; we expect that there is substantial H+ present above 400 km, but the total ion density is so low that we cannot measure it. We see no detectable change in H+ between magnetically quiet and disturbed periods. The H+ proportions seen above the MU radar are much smaller than those seen above Arecibo, which has a similar magnetic latitude but much lower geographic latitude, and are much more comparable to those amounts seen by the higher‐latitude radars at Saint Santin and Millstone Hill. Comparisons with models suggest that at these low altitudes, H+ may well be near its charge‐exchange‐equilibrium value.

Distribution of Seasonally Expressed Storage Proteins in Different-aged Shoots and Roots of `Loring' Peach

During autumnal leaf senescence, leaf nitrogen is translocated to other sites for storage, especially bark tissues. By definition, proteins that accumulate in large amounts in winter and are absent in summer are called storage proteins. Previously, we have characterized three proteins in peach bark tissues that fall into this category. Little is known, however, about the distribution of these proteins in different-aged tissues or whether they have any function other than to act as a nitrogen reserve. The present study characterizes the seasonal distribution of a 60-, 19-, and 16-kDa protein in bark tissues of current-year, 1-year-old, scaffold, and trunk bark, and 4- to 5-year-old roots of `Loring' peach. Verification of protein identity was based on molecular mass and reaction with antibodies directed against each specific protein. Distribution of the proteins was variable. The greatest amount of all three proteins was present in current-year and 1-year-old shoots. These tissues also showed the greatest seasonal variation in the amount of protein present. The 16-kDa protein was present only in the youngest shoots, whereas the 19-kDa was present in all tissues examined. The 60-kDa protein was absent in root tissue. The 60-kDa protein has been identified as a dehydrin, and the 16-kDa protein appears to be related to defensins. The identity of the 19-kDa protein has not been confirmed. The amino acid composition of the three proteins will be presented and the implications of these results on management practices will be discussed.

Bud dormancy in Fagus sylvatica L. I. Chilling and photoperiod as factors determining budbreak

ABSTRACT Bud dormancy release was studied in one- and two-year-old seedlings of two Italian provenances (Camaldoli and Pacentro) of Vagus sylvatica. From the beginning of autumn, seedlings were exposed to different periods of chilling and then placed in controlled environment chambers with long day (LD) and short day (SD). Bud sprouting and relationships among buds in renewal bud growth were examined and relative thermal time calculated. By October, buas were already dormant, and there was no relevant growth of seedlings which were kept for six months under SD and LD conditions. Thermal time, percentage sprouting and mean time to budburst varied consistently with the amount of winter chilling up to 700h < 5°C, when a plateau was reached. Under these conditions daylength did not influence sprouting, which appeared to be, instead, determined by temperature. With shorter exposure to chilling, LD significantly stimulated sprouting. Results also show different growth potentials for the different (based on structure and/or position) types of buds.

Impacts of the Great Lakes on Regional Climate Conditions

Estimates of lake-induced spatial changes of six climate variables (precipitation, mean minimum and mean maximum temperatures, cloud cover, vapor pressure, and wind speed) were derived for the entire Great Lakes basin. These patterns were estimated by a comparison of maps of each weather variable using: (1) all regional climate data, and (2) regional data when observations within an 80-km zone around the lakes were removed. Results generally confirm expectations and prior findings, but point to inadequacies in data collection that limit a highly precise analysis. Lake effects are most noticeable in precipitation and temperature and vary considerably by season, time of day, and lake size. Greatest lake influences are found near Lake Superior where up to 100% more precipitation falls downwind of the lake in winter compared to that expected without its presence. During summer, all lakes cause a downwind decrease in rainfall of 10% to 20%. Mean minimum temperatures in the basin are higher in all seasons and over all lakes. Lake-induced reductions in mean maximum temperatures in the region are observed during spring and summer. Effects on cloud cover are greatest during winter and show increases of approximately 25% in areas downwind of Lakes Superior and Michigan. Conversely, the cool summertime waters of Lakes Michigan and Huron reduce cloudiness roughly 10%. Variations in vapor pressure are consistent with observed changes in temperature. Amounts in winter are estimated to be 10% to 15% higher across the center of the basin, but decrease by roughly 5% to 10% at many lake shore sites in summer. Seasonal wind speed data were considered to lack an appropriate number of quality long-term climate stations to determine spatial lake effects. Surface elevations, increasing east of the basin, complicated detection of effects due solely to the lakes.

Effects of methods of cereal straw disposal, seedbed preparation and sowing method on the establishment, yield and oil content of winter oilseed rape (Brassica napus)

SUMMARYIn the first of two series of experiments the effects of barley straw disposal by burning, chopping and spreading or baling and removing on winter oilseed rape were tested after seedbed preparation either by ploughing in the residue or incorporation in the soil by tine cultivation. These treatments were compared in four field experiments on silty clay loam soils at Rothamsted, UK from 1986 to 1989. The winter rape was either sown in late August or mid-September in seedbeds where either none or 50 kg N/ha had been applied.In the first season, August-sown rape was successfully established after tine cultivation but very dry conditions prevented seedbed preparation after ploughing, consequently all ploughed treatments were sown in September. Continuing dry conditions delayed emergence of the September-sown crop, the resultant small rape seedlings suffered substantial winter kill in some treatments during a period of abnormally low temperatures. Yield from the August-sown treatments was large (c. 40 t/ha) and showed no effect of straw disposal treatment or additional seedbed N. The yield of the September-sown crop was influenced by the amount of winter kill sustained; the smallest yields resulted from tine incorporation, and the largest after ploughing, where they approached those of the early sown crop.In the following three seasons more plants emerged from September than from August sowings. The application of seedbed N increased the plant population of the August-sown crop where the straw had been burnt. Plant losses over winter ranged from 15 to 20% and were unaffected by straw disposal treatment. There were significant differences in yield resulting from season and sowing date. Incorporating chopped straw by tine cultivation significantly decreased yield which, coupled with a lower oil content in the September-sown crop, gave a significantly smaller oil yield.In a second series of field experiments from 1987 to 1989, the effects of improving the timeliness of rape establishment after winter wheat by broadcasting rape seed into standing wheat was compared with conventional sowing after preparing a post-harvest seedbed. After cereal harvest, straw was disposed of either by baling and removing or chopping and spreading over the rape seed. The application of 50 kg N/ha to the stubble or seedbed was also tested, as was the effect of increasing the seed rate from 8 to 16 kg/ha in two seasons.There were always fewer plants established from broadcasting than from drilling. Generally there were fewer winter losses from broadcast seed than from drilled. Applying N to seedbed or stubble had no effect on plant population or survival except where 16 kg/ha seed was sown in 1989 and increased yield in two of the three seasons.In spite of a smaller plant population from broadcast seed, yields were often larger from broadcast than drilled treatments. On average broadcasting the seed and baling the straw gave the largest yield although this was significant only in 1989.

特集 日本の小氷期 文書記録による水氷期の中部日本の気候復元

“The Little Ice Age” started in the 17th century and ended in the middleof the 19th century in Central Japan. The reconstruction of climatic conditions during the Little Ice Age was attempted, based on old documentary records. There are many old documents in which daily weather conditions were recorded. Those records were collected and arranged according to the order of dates. Through the works, weather diagrams were compiled for the historical times in Central Japan. By analyzing the diagrams, some climatic conditions during the historical times (from the end of the 18 th century to the middle of the 19 th century) were reconstructed for Central Japan. The main results are shown as follows.(1) Winter season temperatures were very low in the 1810's and the 1820's. After that it tended to become warmer gradually.(2) Precipitation amounts in winter on the Pacific coastal region is small. However after the 1830's, it increased to the present level.(3) Frequency of the appearance of the winter monsoonal flow pattern was higher in the 1810's and 1820's, and it became lower in the 1830's.(4) The end of the Bai-u season was delayed in the 1780's, 1830's and 1890's. In those periods, cool summers appeared in northern Japan frequently.(5) Heavy rainfalls frequently occurred during the Bai-u season in the middle of the 19th century. On the contrary, rainfall amounts during the Bai-u season were very small in the beginning of the 19th century.(6) In the beginning of the 19th cent ury, climatic condition of summer season was dry with little rain. Conversely, it is wet and much rain in the middle of the 19th century.There were some differences in climatic conditions between the early period and th e middle period of the 19th century. The main causes that bring these differences may have been the changes in general circulation patterns over East Asia. By comparing the climatic conditions in several different regions, the relationship between climatic changes andgeneral circulation patterns will be clarified.

Acid and alkaline phosphatase activities in the clam Ruditapes philippinarum

Acid and alkaline phosphatase activities have been partially characterized in Ruditapes philippinarum (Adams and Reeve, 1850). Two activity peaks at pH=4.5 and pH 10.5 were detected in the gill, digestive gland, mantle, siphon and foot. Acid phosphatase activity was higher than that of alkaline phosphatase. The highest activity for both enzymes was observed in the digestive gland and, in decreasing order, the gill, foot, siphon and mantle. Alkaline phosphatase activity was similar in the mantle, siphon and foot. K m values were determined for both enzymes in the gill and digestive gland. Hill coefficients were near 1, indicating no allosteric behaviour for either enzyme in the two organs. The optimum temperature was the same for acid phosphatase in both gill and digestive gland (50 °C), while for alkaline phosphatase it differed for these two organs (gill, 40 °C; digestive gland, 35 °C). The apparent activation energy was obtained from Arrhenius plots, and ranged from 8.61 kcal/mol for alkaline phosphatase in the gill, to 10.84 kcal/mol for acid phosphatase in the digestive gland. The effects of metals (1 mM conc) on both enzyme activities were assayed in vitro. Hg strongly inhibited the enzyme activities in the gill and digestive gland, probably because of its affinity for the sulphydryl group. Histochemically, acid phosphatase in the gill was located in a granular form throughout the gill cells, but was undetectable in the ciliate epithelium of the gill filaments. Alkaline phosphatase was located in the gill skeleton. Clam size and phosphatase activities were inversely related, probably reflecting a decrease in shell deposition with inereasing size. As a function of season, both enzymes were present in lowest amounts in winter, when undifferentiated sex cells were predominant in the germinative epithelium, and highest in summer, when ripe individuals of both sexes were more frequent.

Heat balance characteristics during fine periods on the lower parts of the Franz Josef Glacier, South Westland, New Zealand

AbstractHeat balance observations were carried out during fine conditions at a site on the lower Franz Josef Glacier in June 1988 and February 1990 and compared with results obtained in August, October, and December 1981. Surface ice melt occurred during all seasons, with the mean melt rate in summer about eight times larger than in winter. The seasonal variation of the various contributions to ice melt was also identified. Sensible heat flux was the dominant heat source, contributing 80 per cent and 55 per cent of the total energy gain in winter and summer, respectively. Latent heat transfer contributed similar amounts in winter (20 per cent) and summer (25 per cent). Net radiation was a heat sink in winter (—13 per cent) and was similar to latent heat transfer in summer at 21 per cent. A newly developed simple method for estimating ice melt using only air temperature is presented and helps to explain the seasonal variations of ice melt.

Variable Mating System of a Sedentary Tropical Duck: The White-Cheeked Pintail (Anas bahamensis bahamensis)

I studied the breeding chronology, courtship activities, pair-bond relation-ships, and parental-care behavior of a sedentary population of White-cheeked Pintails (Anas bahamensis bahamensis) in the Bahamas from 1985 to 1987. The timing and duration of breeding seasons was variable and associated with variation in the onset and amount of winter and spring rainfall. Year-around courtship, mate switches, courtship of brood females, and the formation of extrapair liaisons all reflected intense and continuous competition for quality mates. Most White-cheeked Pintails paired monogamously, but a low level of polygyny occurred regularly: each year, 4 to 9% of paired males had two mates during the breeding season, despite a strongly skewed sex ratio in favor of males (1.45:1). Polygynous males were particularly effective at guarding their mates during the breeding season, an important de¬terminant of female breeding success. The term "male-quality polygyny" is proposed to characterize this form of polygyny. Both long-term pair bonds and mate changes between years were recorded: I0 of 23 marked pairs (43%) stayed together for two or more breeding seasons, while 13 pairs (57%) divorced. Mate retention in the second year was not related to breeding success in the first year. Only females provided parental care, but some males continued to escort and guard their mate for at least part of the brood-rearing period. Although highly variable, male attendance declined with both hatch date and duckling age. Some birds associated as pairs year around, and several pairs stayed together during the wing molt. The sedentary lifestyle in this subtropical climate and the potential for variable and extended breeding seasons appear to be the key ecological factors influencing the complex and variable mating system of this species.

Deposition of anthropogenic sulfate and Pb-210 in the western North Pacific area.

The monthly deposition rates of sodium, calcium, chloride, sulfate and Pb-210 from the atmosphere were measured at 12 stations in various parts of the Japanese Islands for two years. The deposition rates of sea salt particles were higher in the coastal region near the Sea of Japan in winter, demonstrating the fact that the strong winter monsoon produces many sea salt particles. Amounts of chloride, sulfate and calcium in excess of the sea salt component were always observed. The rather uniform annual deposition rates of excess sulfate (3–10g/m2/y) suggest that a large part of this excess sulfate originates in global air pollution. Pb-210, much of which is of upper atmospheric origin, is also deposited in significant amounts in winter. This seasonal change may be due to the replacement of lower air masses over the continental margin area, which yields a two-layer model for the atmospheric transport of chemical constituents. The geographical variation of Pb-210 deposition can be explained using the two-layer model and by assuming a 12 day residence time for the tropospheric aerosols. The deposition rates for sulfate over the ocean area decrease more rapidly with distance from the continental coast than those for Pb-210. This result may show that the atmospheric residence time of sulfate is shorter than that of Pb-210.

Seasonal variations in the mass and composition of brown adipose tissue in the meadow vole, Microtus pennsylvanicus

Wild meadow voles were collected each month of the year and analyzed for the mass and composition of their brown adipose tissue. The relative mass of brown adipose tissue decreased with increasing body weight in both summer and winter.Seasonal changes in the relative mass of brown adipose tissue were inversely related to seasonal changes in ambient temperature. In mature voles, the relative mass of brown adipose tissue was lowest during summer (0.5%) and increased rapidly to a level of 1.7% in early winter. Similarly, immature voles had their lowest relative mass in summer (1.0%) and increased this to 2.3% in winter. Both groups showed some decrease in the winter amount of the tissue when the subnivean environment became established. The percentage composition of brown adipose tissue with respect to water, lipid, and protein did not change significantly through the year.The results provide corroboration for laboratory studies which show that the mass and composition of brown adipose tissue are related to the requirement for cold thermogenesis. In voles, this requirement was present throughout the year and varied only in degree.

水産物の腐敗に関する研究-XIV

Continuing from the last report, we have studied on the process of putrefaction of the minced muscle of Various fishes. It is generally said that the mackerel is apt to be more easily spoiled and causes ptomaine poisoning more occaisionally than the yellowtail. But, when these minced muscles had been stored at same temperature, any difference between these muscles has been scarcely found in the decomposed substances. We have therefore regarded that the difference of easiness in patre-faction between these fishes should be due to the physical properties of these muscular tissues. The minced muscle of the sardine and the bonito has been seemed to us to be similar to the formers in the manner of putrefaction. However, we have observed that there has been a little variation especially in the quantity of histamine in accordance with the time elapsed when the experiment began after catching fishes. It would seem to be a question concerning with the contamination of bacteria. In the same manner, the histamine was found to be developed in a small amount in winter, even in the fish muscle stored at the same temperature as in the case of other seasons, probably owing to a minor existence of histamine producing bacteria in winter. It was found that in the crab meat, the development of volatile base was very large in amount, while the histamine was scarcely produced.

ON FORECASTING WINTER PRECIPITATION AMOUNTS AT WASHINGTON, D. C.

Abstract A simplified model of the rainfall mechanism is used as a guide in developing a statistical formula, with readily measured variables as arguments, for forecasting precipitation amounts in winter at Washington, D. C. The skill of the forecasting method is tested on independent data and for snow cases. To simplify computations involved in using the formula, a nomograph is devised. Suggestions are given for further work on the method.