Vignette d'image

Rebetez, Martine

Nom
Rebetez, Martine
Affiliation principale
Site web
Fonction
Professeure ordinaire
Email
martine.rebetez@unine.ch
Identifiants
https://libra.unine.ch/handle/123456789/403

Résultat de la recherche

Filtres

11
6
51
51
Réinitialiser les filtres

Paramètres

Voici les éléments 1 - 6 sur 6
  • Publication
    Accès libre
    Progress in the study of climatic extremes in northern and central Europe
    (1999)
    Heino, R
    ;
    Brazdil, R
    ;
    Forland, E
    ;
    Tuomenvirta, H
    ;
    Alexandersson, H
    ;
    Beniston, Martin
    ;
    Pfister, Christian
    ;
    Rebetez, Martine 
    ;
    Rosenhagen, G
    ;
    Rosner, S
    ;
    Wibig, J
    A study of the long-term changes of various climatic extremes was made jointly by a number of European countries. It was found that the changes in maximum and minimum temperatures follow, in broad terms, the corresponding well-documented mean temperature changes. Minimum temperatures, however, have increased slightly more than maximum temperatures, although both have increased. As a result, the study confirms that the diurnal temperature range has mostly decreased during the present century in Northern and Central Europe. Frost has become less frequent. Two extreme-related precipitation characteristics, the annual maximum daily precipitation and the number of days with precipitation greater than or equal to 10 mm, show no major trends or changes in their interannual variability. An analysis of return periods indicated that in the Nordic countries there were high frequencies of 'extraordinary' 1-day rainfalls both in the 1930s and since the 1980s. There have been no long-term changes in the number of high wind speeds in the German Eight. Occurrences of thunderstorms and hails show a decreasing tendency in the Czech Republic during the last 50 years. Finally, using proxy data sources, a 500-year temperature and precipitation event graph for the Swiss Mittelland is presented. It shows large interdecadal variations as well as the exceptionality of the latest decade 1986-1995.
  • Publication
    Métadonnées seulement
    Changes in temperature variability in relation to shifts in mean temperatures in the Swiss Alpine region this century
    (Heidelberg New York: Springer, 1998)
    Rebetez, Martine 
    ;
    Beniston, Martin
    ;
    Beniston, Martin
    ;
    Innes, John
  • Publication
    Accès libre
    Changes in sunshine duration are correlated with changes in daily temperature range this century: An analysis of Swiss climatological data
    (1998)
    Rebetez, Martine 
    ;
    Beniston, Martin
    Analyses of the relationship between trends in daily temperature range and those of sunshine duration in the Swiss Alps show a strong correlation at lower elevation sites. The decrease in daily temperature range is associated with a corresponding decrease in sunshine duration. At high elevations, however, this relationship is absent. The decrease in daily temperature range observed this century at lower elevation sites is inferred to be a consequence of an increase in low-level cloudiness. Higher elevation sites lie above the low-level cloud layers and the moisture-laden lower atmospheric boundary layer and as a result do not exhibit the same trends.
  • Publication
    Accès libre
    Regional behavior of minimum temperatures in Switzerland for the period 1979-1993
    (1996)
    Beniston, Martin
    ;
    Rebetez, Martine 
    A series of anomalously cold and warm winters which occurred in Switzerland during the 15-year period from 1979 to 1993 has been analyzed in detail in terms of temperature minima. The warm winters between 1988-1992 were particularly marked in the Alps, where lack of snow had severe consequences for the tourist-based economies of mountain communities. The investigations presented here focus primarily on minimum temperature records for up to 88 climatological observing sites distributed over Switzerland. Analyses of the departures of temperature minima from the 15-year means in warm and cold winters has shown that there is a very significant altitudinal dependency of the anomalies except at low elevations which are subject to fog or stratus conditions; the stratus tends to decouple the underlying stations from processes occurring at higher altitudes. It is also shown that there is a switch in the gradient of the temperature anomaly with height from cold to warm winters. For warm winters, the higher the elevation, the stronger the positive anomaly; the reverse is true for cold winters. The statistics for the 88 observational stations provide a measure of the damping of the climate signal as an inverse function of height. The altitudinal dependency of temperature departures from the mean are the most important feature, followed by latitudinal effects (north and south of the Alps); continentality is not seen to be a major factor in determining the geographical distribution of temperature anomalies at this scale. The present investigation also emphasizes the fact that high elevation records can more readily identify significant interannual climatic fluctuations than at lower-elevation sites. This is also likely to be the case for longer-term climate change, where possible greenhouse-gas warming would presumably be detected with more clarity at higher elevations. This type of study can help orientate future high-resolution climate model studies of climate change and in particular the assessment of model capability in reproducing a range of possible temperature anomalies and their altitudinal dependency.
  • Publication
    Accès libre
    An analysis of regional climate-change in Switzerland
    (1994)
    Beniston, Martin
    ;
    Rebetez, Martine 
    ;
    Giorgi, F
    ;
    Marinucci, M
    An analysis of daily climatological data covering the period from 1901 to 1992 for four locations in Switzerland (Zurich, Lugano, Davos, and Santis) has been made. The study has highlighted the fact that climate change this century is characterized by increases in minimum temperatures of about 2K, a more modest increase in maximum temperatures (in some instances a decrease of maxima in the latter part of the record), little trend in the precipitation data, and a general decrease of sunshine duration through to the mid 1980s. The interannual variability is generally large, and filtering of the data to remove high-frequency noise shows that the regional climate undergoes a series of fluctuations of between 8 and 20 years' duration. The temperature change over this century is of greater magnitude than the global temperature changes published in the literature, reflecting an amplification of the global signal in the Alpine region; warming has been most intense in the 1940s, followed by the 1980s; the cooling which intervened from the 1950s to the late 1970s was not sufficient to offset the warming in the middle of the century. Pressure statistics have been compiled as a means of providing a link between the regional-scale climatological variables and the synoptic, supra-regional scale. These statistics show that pressure also exhibits a number of decadal-scale fluctuations, with the appearance of a new and anomalous behavior in the 1980s; in this decade, pressure reaches annual average values far higher than at other times this century. The pressure field is well correlated with the North Atlantic Oscillation (NAO) Index for distinct periods of the record (1931-1950 and 1971-1990) and is almost decorrelated from the NAO Index for the other decades of the century; this is indicative of transition from one climatic regime to another, dominated by zonal flow when the correlation with the NAO Index is high. In the 1980s, when zonal flow over the North Atlantic is strong, episodes of persistent, anomalously high pressures (blocking highs) are seen to occur over Switzerland, particularly during the winter season. The difference between the zonal and non-zonal regimes is particularly marked between the decade of the 1950s and that of the 1980s. The impact of this change between the 1950s and the 1980s on a number of climatological variables has been investigated statistically in order to provide an illustration of the manner in which changes in synoptic regimes (i.e., 'climate change') impacts upon climate characteristics on a regional scale. The analysis shows that temperature, precipitation, snow depth, and sunshine duration are indeed sensitive to large-scale influences; not only can yearly mean changes be quantified, but also seasonal and monthly fluctuations.
  • Publication
    Accès libre
    Use of LIDAR measurements and numerical models in air pollution research
    (1990)
    Beniston, Martin
    ;
    Wolf, Jean-Pierre
    ;
    Rebetez, Martine 
    ;
    Kölsch, H J
    ;
    Rairoux, P
    ;
    Wöste, L