A statistical analysis of the differences between rainfall estimated by Chennai DWR and conventional rainfall data on monthly and seasonal scales during the Indian northeast monsoon season

The first Doppler Weather Radar (DWR) of India Meteorological Department has been functional at Chennai since the year 2002 providing various meteorological and hydrological products. Validation and statistical analysis of the DWR estimated rainfall (RERF, x) data with rain gauge measured rainfall (RGRF, y) of 34 land based stations located in the semi-circular land area within 100 km radius of Chennai DWR (CDLR100) has been performed for the northeast monsoon (NEM) season of October-November-December (OND) for the 12 year period 2002-13. The monthly and seasonal data have been derived using more than 1.42 lakh discrete daily RERF values available at a high resolution of 333 m × 333 m. The major objective of the study is to compute the various statistical parameters of x and y including the bias between them on monthly and seasonal scales and to draw certain inferences. The analysis was done using three different types of averaging. The yearly means of x and y for OND over CDLR100 manifested both positive and negative epochs with the mean absolute deviation (MAD) computed as 11 cm (17% of mean). The short term normals over CDLR100 are derived as 274.9, 262.6, 96.5 and 629.8 mm for x and 243.8, 254.6, 128.0 and 627.4 mm for y for October, November, December and OND yielding bias values of -31.2, -8.0, 31.5 and -2.4 mm respectively. The MAD for OND rainfall computed by pooling in all the 12 ´ 34 values is quite substantial at around 19 cm (30% of mean). The RF bias for each month / NEM season is shown to be independent of the geographical locations of the stations using correlation analysis. Based on the raw values of x and a proportional correction technique, estimated values of at the 1.42 lakh grid points of CDLR100 were derived yielding spatial means of 273.3, 262.2, 92.5 and 628.4 mm for x and 243.4, 254.3, 122.9 and 622.1 mm for for the three months and OND respectively. The importance of size of the bias in the correct interpretation of x has been discussed. A few suggestions based on certain statistical considerations have been putforth for decreasing the bias.

Riverine characteristics and adult demography influence female lake sturgeon (Acipenser fulvescens) spawning behavior, reproductive success, and ovarian quality

Abiotic conditions and demographic factors can influence the timing of spawning. Behavioral plasticity allows females to select spawning conditions that are conducive to offspring development; however, reproductive costs associated with delaying spawning are not well understood. In this study, factors influencing timing of female spawning, residence time (RT), and reproductive success (RS) during two seasons were determined, and plasma testosterone concentrations were used to quantify atretic rates in a wild, lake sturgeon (Acipenser fulvescens) population. For the 123 females monitored, RT ranged from 1 to 23 days and was influenced by arrival date, temperature, discharge, and male number, with the latter having the largest influence. RS varied due to arrival date, temperature, discharge, male number, male length, and operational sex ratio. Two females had testosterone levels indicative of atresia and RS estimates lower than yearly means; however, most females had normal ovaries, suggesting little reproductive costs of plasticity in spawning ground residency time. Results demonstrate the multitude of factors influencing female reproductive behavior and RS, highlighting the importance of abiotic and demographic conditions to recruitment in wild populations.

Observations of Seasonal Upwelling and Downwelling in the Beaufort Sea Mediated by Sea Ice

We present observational estimates of Ekman pumping in the Beaufort Gyre region. Averaged over the Canada Basin, the results show a 2003–14 average of 2.3 m yr−1 downward with strong seasonal and interannual variability superimposed: monthly and yearly means range from 30 m yr−1 downward to 10 m yr−1 upward. A clear, seasonal cycle is evident with intense downwelling in autumn and upwelling during the winter months, despite the wind forcing being downwelling favorable year-round. Wintertime upwelling is associated with friction between the large-scale Beaufort Gyre ocean circulation and the surface ice pack and contrasts with previous estimates of yearlong downwelling; as a consequence, the yearly cumulative Ekman pumping over the gyre is significantly reduced. The spatial distribution of Ekman pumping is also modified, with the Beaufort Gyre region showing alternating, moderate upwelling and downwelling, while a more intense, yearlong downwelling averaging 18 m yr−1 is identified in the northern Chukchi Sea region. Implications of the results for understanding Arctic Ocean dynamics and change are discussed.

Radiation budget estimates over Africa and surrounding oceans: inter-annual comparisons

Three independent datasets of Radiation Budget at the top of the atmosphere (TOA) spanning two decades are compared: the Scanner Narrow Field of View data (from ERBE, ScaRaB, and CERES instruments, 1985–2005), the ERBS Nonscanner Wide Field of View data (1985–1998) and the simulated broadband fluxes from the International Satellite Cloud Climatology Project (ISCCP-FD, 1983–2004). The analysis concerns the shortwave (SW) reflected flux, the longwave (LW) emitted flux and the net flux at the Top Of the Atmosphere (TOA) over Africa and the surrounding oceans (45° S–45° N/60° W–60° E), a region particularly impacted by climate variability. For each month, local anomalies are computed with reference to the average over this large region, and their differences between the 2002–2005 and 1985–1989 periods are analysed. These anomalies are relative values and are mostly independent on the absolute observed trends (about 2.5 Wm−2 per decade) which may be affected by possible calibration drifts. Large inter-annual variations are observed locally. Over a part of the South East Atlantic (35°–10° S/10° W–10° E), including the marine low cloud area off Angola, there is a decrease of the yearly means of net flux estimated to 2.2, 3 and 6 Wm−2 respectively for the Scanner, Nonscanner and ISCPP-FD data. Over a narrow strip of the Sahel Zone, the net flux increases by about 5 Wm−2.

Long-term changes in hydrographic conditions in northern Adriatic and its relationship to hydrological and atmospheric processes

A very long data series (1921–2000) of hydrographic parameters (temperature, salinity and density) collected in surface and bottom layers at a station in the coastal zone in the northeastern Adriatic was analyzed. Seasonal and interannual variability of the three parameters is described on the basis of monthly and yearly averages. The seasonal cycles obtained were found to be typical for the northern Adriatic. Interannual analysis showed that there was no trend in temperature, salinity and density in the region during the interval analyzed. The long-term series of yearly means of hydrographic parameters were related to the long-term series of yearly means of several hydrological/atmospheric parameters using different time lags of between 0 and 4 years. These parameters are surface heat flux gained by insolation Qs computed for Trieste, precipitation P in Trieste, Po River discharge rate R and two atmospheric oscillation indexes, a Mediterranean Oscillation (MO) index and North Atlantic Oscillation (NAO) index. At zero time lag the interannual changes at the surface were found to be significantly related to changes in the Qs and NAO index (temperature) and R (salinity and density). At the same time lag the changes in the bottom were found to be related to the MO index (temperature, salinity and density). Additionally, bottom salinity and density were significantly related to R at a time lag of 1 year. Key words. Oceanography: Physical (air-sea interactions; hydrography)

Means and Trends of Shortwave Irradiance at the Surface Estimated from Global Energy Balance Archive Data

Means and trends of shortwave irradiance at the earth’s surface are calculated from pyranometer measurements stored in the Global Energy Balance Archive (GEBA) database. The GEBA database contains the most comprehensive set of shortwave irradiance monthly means. The relative random error of measurement is approximately 5% of a monthly mean in general and approximately 2% of a yearly mean. The shortwave irradiance yearly means are analyzed in a 2.5° × 2.5° grid. In average example grid cells in Europe (no large altitude differences, no coasts), the difference of shortwave irradiance yearly means measured at different stations (station effect) is less than 5% of the cell mean, and the interannual variability is approximately 4% of the cell mean. On most continents, shortwave irradiance decreases significantly in large regions, and significant positive trends are observed only in four small regions.

“Heat-Valve” Effects in the Ground Thermal Regime

A one-dimensional model of a freezing and thawing ground with a seasonally varying surface cover was analyzed. Analytical and numerical techniques were used primarily to study the factors that produce differences between the yearly means of the air and ground temperatures. It was shown that the variation of the surface cover characteristics in phase with the annual air temperature wave can generate the heat-valve effect which is responsible for raising the average ground temperature above the average air temperature. This temperature difference was, however, very sensitive to changes to the surface cover properties indicating how disturbances to the surface cover could cause melting of a permafrost soil.

Nine-Year Cross-Sectional Study of Change in Self-Concepts of College Freshmen

Entering freshman classes at a midwest Catholic university were administered Gough's Adjective Check List (1965) each year from 1965 to 1973. Random samples from each class were drawn and compared on five constructed scales of self-concept. The N for each of the years was 75. Significant year-to-year differences were found on 2 of the 5 scales. In addition, a significant “wave-like” trend in the yearly means of one scale was observed. These differences indicated a change for groups in sociability and contemplative independence areas of self-concept.

Jordtemperaturmålinger i Frederikshåb

For two years, 1/9/1961 - 31/8/1963, temperature measurements have been carried out at Frederikshåb (South Greenland) by GGU (Geological Survey of Greenland) and GTO (Technical Organization of Greenland). The measurements were carried out as an extension of the measurements made at Godthåb in the years 1949 - 60 (unpublished). The temperatures were measured with eleven thermistores placed in nearly water saturated fine to coarse silt. The thermistores were placed at ca. 0.5 m depth intervals, starting with a depth of 0.5 m, ending with 5.5 m (see fig. 2). For the entire period readings were taken daily at 12.00. The temperature readings are believed to be correct within 0.3 - 0.4 °C. Monthly and yearly means have been calculated (Table II). As yearly means for the years involved were nearly the same, the results have been combined to show a "mean year" (curves fig. 3). The curves show a marked skewness, the temperature in boring no. 11 rising for only three months of the year while going down for nine months. The effect has been reduced to rising temperature for five months, falling for seven months, in boring no. 1. The time lag between the maximum or minimum for the two curves is approx. three months. The damping of the amplitudes of the curves with increasing depth has been used to calculate the depth at which the temperature range is less than the error of the thermistores. This calculated depth is approx. eight meters.

Some Financial and Statistical Considerations of the Old Age Pension Scheme

There are many references in the pages of the Journal to Old Age Pensions, and in view of the Act of last year the subject—from a financial and statistical aspect—may be discussed without transgressing on questions of State policy. I therefore venture to submit the following notes of some of the financial and statistical questions involved, stimulated in so doing by Mr. G. F. Hardy's statement in his Presidential Address, that he believed our most important work lies in the proper application of actuarial principles to the many practical questions which arise from time to time.Old age pensions ranging from 1s. to 5s. a week according to the yearly means of the pensioners are granted to British subjects resident in the United Kingdom who have attained the age of seventy years, provided their yearly means do not exceed ￡31 10s., and provided they are not disqualified on the ground of Poor Law Relief, imprisonment, or the other reasons set forth in Section 3 of the Act.