Suomen talviukkoset 2003-2007

Tutkimuksen tarkoitus on kartoittaa Suomen talviukkosten ominaisuuksia ja klimatologiaa. Tiedot Suomen talviukkosten klimatologista tutkimusta varten kerättiin mm. salamanpaikantimilta ja ihmisten IL:lle tiedottamista havainnoista, SYNOP-kartoilta, rintama-analyyseistä, luotauksista ja luotaustietojen pohjalta piirretyistä salamakartoista sekä sadetutkan kuvista. Tutkimuksessa määriteltiin talviukkoseksi yksi tai useampi salamahavainto säätilanteessa, jossa salamahavaintopaikkaan ja -aikaan nähden lähimmistä synop-havainnoista ainakin yhdessä on havaittu joko ≤ 0 °C lämpötila tai lumi- tai räntäsadetta. Näin rajattuna vuosina 2003-2007 talviukkostapauksia oli 19 kpl. Tapaukset jakaantuivat melko tasaisesti loka-marraskuun vaihteen ja huhtikuun välille, pienet maksimit olivat marras- ja helmikuussa. Tapausten esiintymisajankohtia rajoitti siis vain talviukkosten määritelmän mukaisten sääolosuhteiden esiintyminen. Vuorokaudenajalla ei ollut merkittävää vaikutusta talvisalamoiden esiintymiselle. Alueellisesti talviukkoset painottuivat maan lounaisosaan mutta niitä havaittiin koko maassa Käsivarren Lappia myöten. 16 tapauksessa 19:sta talviukkoset havaittiin okluusiorintamaksi analysoidun rintaman yhteydessä. Yhdessä tapauksessa rintama oli analysoitu kylmäksi ja kahdessa rintama-analyysi oli epäselvä. Matalapaineen keskus sijaitsi iskuhavaintopaikkoihin nähden yleensä lännen puolella. Lännen puolen yleisyyden aiheutti okluusiorintamien kiertosuunta myötäpäivään matalapaineen keskukseen nähden. Pintalämpötila oli lähes kaikissa talviukkostapauksissa lähellä nollaa ja havaintopaikan lähellä olevissa SYNOP-havainnoissa havaittiin useissa tapauksissa sadetta sekä vetenä että kiinteässä olomuodossa. CAPE:n arvot olivat joko nollassa tai hyvin lähellä sitä iskuhavaintoihin nähden lähimmissä luotauksissa. Lämmintä advektiota havaittiin lähes kaikissa tutkituissa luotauksissa, myös sulan meren vaikutus näkyi tuloksissa talviukkosia edistävänä tekijänä. Maasalamoita havaittiin talviukkosten yhteydessä useimmin 1 tai 2 ja iskuja salamaa kohden 1 tai 2. Havaituista maasalamoista positiivisia oli 46 % ja negatiivisia 54 %. Tapaustutkimukset tehtiin kahdesta vuosien 2003-2007 talviukkosia hyvin edustavasta tapauksesta sekä yhdestä salamamäärältään poikkeuksellisen runsaasta tapauksesta.

Responses of Scots pine to nickel and copper exposure and herbivory

The goal of this thesis was to examine the ecophysiological responses of Scots pine (Pinus sylvestris L.), with an emphasis on the oxidative enzyme peroxidase and plant phenolics to environmental stresses like elevated levels of nickel (Ni) and copper (Cu), and herbivory. The effects of Ni and Cu were studied in a gradient survey at a sulphur dioxide contaminated site in the Kola Peninsula, and with experiments in which seedlings were exposed to Ni mist or to Ni and Cu amended into the soil. In addition, experimental Ni exposure was combined with disturbance of the natural lichen cover of the forest ground layer. Pine sawfly attack was simulated in the early season defoliation experiment, in which mature Scots pine were defoliated (100 %) during two successive years in a dry, nutrient-poor Scots pine stand. In addition, the effect of previous defoliation on the growth of sawfly (Diprion pini L.) larvae was studied. Apoplastic peroxidase activity was elevated in the needles of pine in a Ni- , Cu- and SO2- polluted environment, which indicated an increased oxidative stress. Increased foliar peroxidase activity due to Ni contamination was shown in the experiment, in which Ni was added as mist. No such response was found in peroxidase acitivity of the roots exposed to elevated Ni and/or Cu in the soil. Elevated Ni in the soil increased the concentration of foliar condensed tannins, which are able to bind heavy metals in the cells. Addition of low levels of Ni in the soil appeared to benefit pine seedlings, which was seen as promoted shoot growth and better condition of the roots. Wet Ni deposition of 2000 mg m-2 reduced growth and survival of pine seedlings, whereas deposition levels 200 mg m-2 or 20 mg m-2 caused no effects in a 2-y lasting experiment. The lichen mat on the forest floor did not act as an effective buffer against the adverse impacts of heavy metals on pine seedlings. However, some evidence was found indicating that soil microbes profited from the lichen mat. Artificial defoliation increased peroxidase activity in the Scots pine needles. In addition, defoliation decreased nitrogen, diamine putrescine and glucose concentrations in the needles and increased the concentrations of several phenolic compounds, starch and sucrose. Previous artificial defoliation led to poor growth of sawfly larvae reared on the pines, suggesting delayed induced resistance in Scots pine. However, there was no consistent relationship between inducibility (proportional increase in a compound following defoliation) and adverse effects on the growth of pine sawfly larvae. The observed inducible responses in needle phenolics due to previous defoliation thus appear to represent non-specific responses against sawflies.

Exploiting ground-based measurements of the Global Positioning System for numerical weather prediction

Data assimilation provides an initial atmospheric state, called the analysis, for Numerical Weather Prediction (NWP). This analysis consists of pressure, temperature, wind, and humidity on a three-dimensional NWP model grid. Data assimilation blends meteorological observations with the NWP model in a statistically optimal way. The objective of this thesis is to describe methodological development carried out in order to allow data assimilation of ground-based measurements of the Global Positioning System (GPS) into the High Resolution Limited Area Model (HIRLAM) NWP system. Geodetic processing produces observations of tropospheric delay. These observations can be processed either for vertical columns at each GPS receiver station, or for the individual propagation paths of the microwave signals. These alternative processing methods result in Zenith Total Delay (ZTD) and Slant Delay (SD) observations, respectively. ZTD and SD observations are of use in the analysis of atmospheric humidity. A method is introduced for estimation of the horizontal error covariance of ZTD observations. The method makes use of observation minus model background (OmB) sequences of ZTD and conventional observations. It is demonstrated that the ZTD observation error covariance is relatively large in station separations shorter than 200 km, but non-zero covariances also appear at considerably larger station separations. The relatively low density of radiosonde observing stations limits the ability of the proposed estimation method to resolve the shortest length-scales of error covariance. SD observations are shown to contain a statistically significant signal on the asymmetry of the atmospheric humidity field. However, the asymmetric component of SD is found to be nearly always smaller than the standard deviation of the SD observation error. SD observation modelling is described in detail, and other issues relating to SD data assimilation are also discussed. These include the determination of error statistics, the tuning of observation quality control and allowing the taking into account of local observation error correlation. The experiments made show that the data assimilation system is able to retrieve the asymmetric information content of hypothetical SD observations at a single receiver station. Moreover, the impact of real SD observations on humidity analysis is comparable to that of other observing systems.

Retirement Transition and Well-being : A 16-year Longitudinal Study

The ageing of the labour force and falling employment rates have forced policy makers in industrialized countries to find means of increasing the well-being of older workers and of lengthening their work careers. The main objective of this thesis was to study longitudinally how health, functional capacity, subjective well-being, and lifestyle change as people grow older, and what effect retirement has on these factors and on their relationships. The present study is a follow-up questionnaire study of Finnish municipal workers, conducted in 1981 to 1997 at the Finnish Institute of Occupational Health. In 1981, a postal questionnaire was sent to 7344 municipal workers in different parts of Finland. The respondents were born between 1923 and 1937. A total of 6257 persons responded to the first questionnaire. In the end, a total of 3817 persons had responded to all four (1981, 1985, 1992, 1997) questionnaires. (The response rate was 69% of the living participants). Cross-tabulations, comparison of means, logistic regression analyses and general linear models with repeated measures were used to derive the results. The transition from work life to retirement, and the following years as a pensioner were associated with many changes. Involvement in various activities increased during the transition stage but later decreased to the previous level. Physical exercise was an exception: it became increasingly popular over the years. Perceived health improved markedly from the working stage to the retirement transition stage, even though morbidity increased steadily during the follow-up. On the other hand, functional capacity decreased over the follow-up, especially among those who were occupationally active until the retirement stage. Subjective well-being remained stable during the follow-up period. There were, however, great differences based on the type of work, favouring those whose work had been mental in nature. The impact of activity level on maintaining well-being became greater during the follow-up, whereas the effect of physical functioning diminished. Good physical functioning and an active life-style contributed to staying on at work until normal retirement age. Also work-related factors, i.e. possibilities for development and influence at work, responsibility for others, meaningful work, and satisfaction with working time arrangements were positively related to continuing working. The transition from work to retirement had a positive impact on a person s health and functional capacity. The study results support the view that it should be possible to ease one s work pace during the last years of a work career. This might lower the threshold between work and retirement and convince people that there will still be time to enjoy retirement also a few years later.

Publishing in the Networked World: Transforming the Nature of Communication, 14th International Conference on Electronic Publishing 16-18 June 2010, Helsinki, Finland

The title of the 14th International Conference on Electronic Publishing (ELPUB), “Publishing in the networked world: Transforming the nature of communication”, is a timely one. Scholarly communication and scientific publishing has recently been undergoing subtle changes. Published papers are no longer fixed physical objects, as they once were. The “convergence” of information, communication, publishing and web technologies along with the emergence of Web 2.0 and social networks has completely transformed scholarly communication and scientific papers turned to living and changing entities in the online world. The themes (electronic publishing and social networks; scholarly publishing models; and technological convergence) selected for the conference are meant to address the issues involved in this transformation process. We are pleased to present the proceedings book with more than 30 papers and short communications addressing these issues. What you hold in your hands is a by-product and the culmination of almost a Year long work of many people including conference organizers, authors, reviewers, editors and print and online publishers. The ELPUB 2010 conference was organized and hosted by the Hanken School of Economics in Helsinki, Finland. Professors Turid Hedlund of Hanken School of Economics and Yaşar Tonta of Hacettepe University Department of Information Management (Ankara, Turkey) served as General Chair and Program Chair, respectively. We received more than 50 submissions from several countries. All submissions were peer-reviewed by members of an international Program Committee whose contributions proved most valuable and appreciated. The 14th ELPUB conference carries on the tradition of previous conferences held in the United Kingdom (1997 and 2001), Hungary (1998), Sweden (1999), Russia (2000), the Czech Republic (2002), Portugal (2003), Brazil (2004), Belgium (2005), Bulgaria (2006), Austria (2007), Canada (2008) and Italy (2009). The ELPUB Digital Library, http://elpub.scix.net serves as archive for the papers presented at the ELPUB conferences through the years. The 15th ELPUB conference will be organized by the Department of Information Management of Hacettepe University and will take place in Ankara, Turkey, from 14-16 June 2011. (Details can be found at the ELPUB web site as the conference date nears by.) We thank Marcus Sandberg and Hannu Sääskilahti for copyediting, Library Director Tua Hindersson – Söderholm for accepting to publish the online as well as the print version of the proceedings. Thanks also to Patrik Welling for maintaining the conference web site and Tanja Dahlgren for administrative support. We warmly acknowledge the support in organizing the conference to colleagues at Hanken School of Economics and our sponsors.

Silva Fennica Vol. 16, 1982.

Julkaistu Silva Fennica Vol. 17(1) -numeron liitteenä.