References of "Erpicum, Michel"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailGreenland ice sheet projections from IPCC AR4 global models
Franco, Bruno ULg; Fettweis, Xavier ULg; Erpicum, Michel ULg et al

Poster (2009, April)

The atmosphere-ocean general circulation models (AOGCMs) used for the IPCC 4th Assessment Report (IPCC AR4) are evaluated for the Greenland ice sheet (GrIS) current climate modelling. The most efficient ... [more ▼]

The atmosphere-ocean general circulation models (AOGCMs) used for the IPCC 4th Assessment Report (IPCC AR4) are evaluated for the Greenland ice sheet (GrIS) current climate modelling. The most efficient AOGCMs are chosen by comparison between the 1970-1999 outputs of the Climate of the twentieth Century experiment (20C3M) and reanalyses (ECMWF, NCEP/NCAR). This comparison reveals that surface parameters such as temperature and precipitation are highly correlated to the atmospheric circulation (500 hPa geopotential height) and its interannual variability (North Atlantic oscillation). The outputs of the three most efficient AOGCMs are then used to assess the changes planned by three IPCC greenhouse gas emissions scenarios (SRES) for the 2070-2099 period. Future atmospheric circulation changes should dampen the west-to-east circulation (zonal flow) and should enhance the Meridional Overturning Circulation (MOC). As a consequence, this provides more heat and moisture to the GrIS, increasing temperature on the whole ice sheet and precipitation on the north-eastern region. It is also shown that the GrIS surface mass balance (SMB) anomalies from the SRES A1B scenario are about -300 km³/yr with respect to the 1970-1999 period, leading to 5 cm of global sea-level rise (SLR) for the end of the 21st century. This work helps to choose the boundaries conditions for AOGCMs downscaled future projections. [less ▲]

Detailed reference viewed: 36 (11 ULg)
Full Text
See detailCycles found in air temperature data and proxy series using the Morlet wavelet method
Nicolay, Samuel ULg; Mabille, Georges ULg; Fettweis, Xavier ULg et al

Scientific conference (2009, February 25)

Detailed reference viewed: 11 (6 ULg)
Full Text
Peer Reviewed
See detailGreenland ice sheet surface mass balance projections from IPCC AR4 global models
Franco, Bruno ULg; Fettweis, Xavier ULg; Erpicum, Michel ULg

Poster (2009, January 28)

Results from atmosphere-ocean general circulation models (AOGCM's) for the IPCC 4th Assessment Report are used to investigate surface mass balance (SMB) future projections of the Greenland ice sheet (GrIS ... [more ▼]

Results from atmosphere-ocean general circulation models (AOGCM's) for the IPCC 4th Assessment Report are used to investigate surface mass balance (SMB) future projections of the Greenland ice sheet (GrIS). The most efficient models for the GrIS climate modeling are chosen by comparison between the 1970-1999 outputs (averages and trends) from the Climate of the twentieth Century Experiment (20C3M) and reanalyses (ECMWF, NCEP) as well as observations (ice core measurements). The outputs from these most efficient models are after used to assess changes planned by the IPCC greenhouse gas emissions scenarios (SRES) for the 2070-2099 period. The GrIS SMB projections are estimated from changes in precipitation and temperatures from these AOGCM's outputs. However, large uncertainties remain in these SMB projections based on simplified physics and huge model outputs. High resolution simulations made with regional models (which simulate explicitly the SMB by taking into account the surface feedbacks) forced at their boundaries by a GrIS well-adapted AOGCM could bring more precise brief replies. [less ▲]

Detailed reference viewed: 20 (3 ULg)
Full Text
See detailNew cycles found in air temperature data and proxy series using the Morlet wavelet method
Nicolay, Samuel ULg; Mabille, Georges ULg; Fettweis, Xavier ULg et al

Conference (2009, January 13)

We use the wavelet transform to detect cycles in air temperature data and proxy series

Detailed reference viewed: 8 (3 ULg)
Full Text
Peer Reviewed
See detailEstimation de la transparence de l'atmosphère par ciel clair à la Station Scientifique des Hautes-fagnes (SSHF), Mont Rigi, Belgique. Comparaison avec la Station d'Uccle-Bruxelles (IRM)
Dury, Marie ULg; Ginion, Serge; Erpicum, Michel ULg

in Bulletin de la Société Géographique de Liège (2009), 51(2008), 5-16

This paper deals with the study of the transparency of the atmosphere on clear sky at the Mont Rigi (Belgian Hautes-Fagnes) with the aim of underlining the particularities of the air composition in the ... [more ▼]

This paper deals with the study of the transparency of the atmosphere on clear sky at the Mont Rigi (Belgian Hautes-Fagnes) with the aim of underlining the particularities of the air composition in the Hautes-Fagnes region and quantifying its influence on global solar radiation. We used the following data: solar elevation, water vapor content (characterized by atmospheric water depth) and solar extraterrestrial irradiation at the top of the atmosphere. Due to a lack of direct information about atmospheric pollution, we compared global radiation received at the Hautes-Fagnes scientific station (SSHF) on clear sky with that stored in the same conditions in Uccle (Brussels), the Belgian reference station (Royal meteorological institute, RMI) and urban area. [less ▲]

Detailed reference viewed: 67 (13 ULg)
Full Text
Peer Reviewed
See detail30 and 43 months period cycles found in air temperature time series using the Morlet wavelet
Nicolay, Samuel ULg; Mabille, Georges ULg; Fettweis, Xavier ULg et al

in Climate Dynamics (2009), 33

A wavelet-based methodology is applied to relevant climatic indices and air temperature records and allow to detect the existence of unexpected cycles. The scale spectrum shows the presence of two cycles ... [more ▼]

A wavelet-based methodology is applied to relevant climatic indices and air temperature records and allow to detect the existence of unexpected cycles. The scale spectrum shows the presence of two cycles of about 30 and 43 months, respectively, in the air–temperature time series, in addition to the well-known cycles of 1 day and 1 year. The two cycles do not affect the globe uniformly: some regions seem to be more influenced by the period of 30 months (e.g. Europe), while other areas are affected by the period of 43 months (e.g. North-West of the USA). Similar cycles are found in the indices and the regions influenced by these indices: the NAO index and the Western Europe display a cycle of 30 months, while the cycle of 43 months can be found in the ENSO index and in regions where it is known to have an impact. [less ▲]

Detailed reference viewed: 44 (16 ULg)
Full Text
See detailAnalysis of climatic conditions of wildfires in Belgium with an automatic daily atmospheric circulation patterns classification
Erpicum, Michel ULg; Fettweis, Xavier ULg; Mabille, Georges ULg

Conference (2008, October 02)

An automatic daily atmospheric circulation patterns classification was built using the geopotential heights of 850 hPa level from the ECMWF (re)analysis over the period 1958-2007. The classification is ... [more ▼]

An automatic daily atmospheric circulation patterns classification was built using the geopotential heights of 850 hPa level from the ECMWF (re)analysis over the period 1958-2007. The classification is based on a similarity index between two 850hPa geopotential maps centred on Belgium, taking into account the slope difference between both daily geopotential surfaces as well as the absolute geopotential difference between both surfaces. Wildfire occurrences are analysed in April and September together with monthly frequencies and persistences of daily atmospheric circulation patterns types as well as with monthly variability of weather climate conditions. [less ▲]

Detailed reference viewed: 9 (2 ULg)
Full Text
Peer Reviewed
See detailNew cycles found in air temperature data and proxy series
Nicolay, Samuel ULg; Mabille, Georges ULg; Fettweis, Xavier ULg et al

Conference (2008, October 01)

We apply the wavelet transform tool to detect unsuspected cycles in several climatic time series

Detailed reference viewed: 7 (1 ULg)
Full Text
Peer Reviewed
See detailSolar activity in connection with a 2.5 years periode cycle in air temperature time series using the Morlet wavelet method
Nicolay, Samuel ULg; Mabille, Georges ULg; Fettweis, Xavier ULg et al

Conference (2008, April 17)

The Morlet wavelet is applied to air temperature time series obtained from several weather stations and reveals the existence of a period cycle of 20-30 months since 1950, with an estimated amplitude of 0 ... [more ▼]

The Morlet wavelet is applied to air temperature time series obtained from several weather stations and reveals the existence of a period cycle of 20-30 months since 1950, with an estimated amplitude of 0.5 C. The origin of this period is investigated by computing the scale spectra associated to the principal indices that characterize air mass flows in the troposphere and the stratosphere, as well as the signals related to the sunspot number and the solar flux. Each analysed signal shows this period of approximatively 2.5 years. This suggests that the 2.5 years-cycle could be resulted from the solar activity. [less ▲]

Detailed reference viewed: 13 (3 ULg)
Full Text
Peer Reviewed
See detailAutomatic 1958-2007 daily weather pattern classification applied to an analysis of climatic conditions of wildfires in eastern Belgium
Erpicum, Michel ULg; Fettweis, Xavier ULg; Mabille, Georges ULg et al

Poster (2008, April)

The daily atmospheric circulation patterns classification is founded on a 100 km regular grid centred on Belgium. The geopotential heights of 500, 850 and 1000 hPa levels were extracted <br />from the ERA ... [more ▼]

The daily atmospheric circulation patterns classification is founded on a 100 km regular grid centred on Belgium. The geopotential heights of 500, 850 and 1000 hPa levels were extracted <br />from the ERA-40 database on the period 1958-2002 and from ECMWF operational analysis until the end of year 2007. The classification was based on a similarity index calculated on the orientation of exaggerated slopes of different daily geopotential fields. Wildfire occurrences were analyzed in April and September (which are the two months with the most frequent wildfire-days in Belgium) together with monthly frequencies and persistences of daily atmospheric circulation pattern classes as well as with yearly variability of weather climate conditions. [less ▲]

Detailed reference viewed: 35 (4 ULg)
Full Text
Peer Reviewed
See detailLast century Greenland ice sheet surface mass balance projections from IPCC AR4 global models
Franco, Bruno ULg; Fettweis, Xavier ULg; Erpicum, Michel ULg

Poster (2008, April)

Results from atmosphere-ocean general circulation models (AOGCM's) for the IPCC 4th Assessment Report are used to investigate surface mass balance (SMB) future projections of the Greenland ice sheet (GrIS ... [more ▼]

Results from atmosphere-ocean general circulation models (AOGCM's) for the IPCC 4th Assessment Report are used to investigate surface mass balance (SMB) future projections of the Greenland ice sheet (GrIS). The most efficient models for the GrIS climate modeling are chosen by comparison between the 1970-1999 outputs (averages and trends) from the 20C3M Experiment outputs, and the reanalyses (ECMWF, NCEP) as well as climatologies. The SMB is estimated from the summer temperature (from which is deduced the run-off) and annual snowfall from the well-adapted AOGCM's. It is validated with 1970-1999 results from the regional climate model MAR by interpolating the AOGCM's outputs on the MAR grid. However, large uncertainties remain in these SMB projections due to the simplified physic and coarse AOGCM's resolution. High resolution simulations made with the MAR model (which simulates explicitly the SMB by taking into account the surface feedbacks) forced at its boundaries by a GrIS well-adapted AOGCM could bring more precise brief replies. [less ▲]

Detailed reference viewed: 31 (4 ULg)
Full Text
Peer Reviewed
See detailEstimation of the 1900-2100 Greenland ice sheet surface mass balance
Fettweis, Xavier ULg; Hanna, E.; Gallée, H. et al

Conference (2008, April)

Detailed reference viewed: 17 (3 ULg)
Full Text
Peer Reviewed
See detailEstimation of the Greenland ice sheet surface mass balance for the 20th and 21st centuries
Fettweis, Xavier ULg; Hanna, Edward; Gallée, Hubert et al

in The Cryosphere [=TC] (2008), 2

Results from a regional climate simulation (1970–2006) over the Greenland ice sheet (GrIS) reveals that more than 97% of the interannual variability of the modelled Surface Mass Balance (SMB) can be ... [more ▼]

Results from a regional climate simulation (1970–2006) over the Greenland ice sheet (GrIS) reveals that more than 97% of the interannual variability of the modelled Surface Mass Balance (SMB) can be explained by the GrIS summer temperature anomaly and the GrIS annual precipitation anomaly. This multiple regression is then used to empirically estimate the GrIS SMB since 1900 from climatological time series. The projected SMB changes in the 21st century are investigated with the set of simulations performed with atmosphere-ocean general circulation models (AOGCMs) of the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR4). These estimates show that the high surface mass loss rates of recent years are not unprecedented in the GrIS history of the last hundred years. The minimum SMB rate seems to have occurred earlier in the 1930s and corresponds to a zero SMB rate. The AOGCMs project that the SMB rate of the 1930s would be common at the end of 2100. The temperature would be higher than in the 1930s but the increase of accumulation in the 21st century would partly offset the acceleration of surface melt due to the temperature increase. However, these assumptions are based on an empirical multiple regression only validated for recent/current climatic conditions, and the accuracy and time homogeneity of the data sets and AOGCM results used in these estimations constitute a large uncertainty. [less ▲]

Detailed reference viewed: 188 (17 ULg)
Full Text
Peer Reviewed
See detailCirculations atmosphériques et anomalies de fonte à la surface de la calotte glaciaire du Groenland
Fettweis, Xavier ULg; Mabille, Georges ULg; Erpicum, Michel ULg

in Bulletin de la Société Géographique de Liège (2008), 51

With the aim to study the impact of the 500hPa general circulation on the Greenland ice sheet surface melt simulated by the regional climate model MAR, we developed a new Circulation Type Classification ... [more ▼]

With the aim to study the impact of the 500hPa general circulation on the Greenland ice sheet surface melt simulated by the regional climate model MAR, we developed a new Circulation Type Classification (CTC) based on the 500hPa geopotential height from the ECMWF (re)analysis over the period 1958-2007. This CTC shows that the dominant mode of the regional atmospheric variability around the Greenland is linked to the North Atlantic Oscillation (NAO) and that the surface anomalies are highly correlated to the general circulation. It explains also why a record surface melt was observed during the summer 2007. The 27th August of 2003, where the temperature was 10°C higher than the normal, is the consequence of an almost unique 500 hPa circulation in the 50 last years. [less ▲]

Detailed reference viewed: 90 (18 ULg)
See detailClimatologie - Topoclimatologie
Erpicum, Michel ULg

Book (2008)

Detailed reference viewed: 44 (16 ULg)
Full Text
See detailContribution à l'étude du climat de trois cavités souterraines belges
Piron, Julie; Erpicum, Michel ULg; Ek, Camille ULg et al

in Bulletin de la Société Royale Belge d'Etudes Géologiques et Archéologiques (2007), XLVI

Some temperature and CO2 measures have been made for one year in the cave of Ramioul and in the cave of Comblain-au-Pont, and for six months in the underground quarry of Petit-Lanaye inférieure ... [more ▼]

Some temperature and CO2 measures have been made for one year in the cave of Ramioul and in the cave of Comblain-au-Pont, and for six months in the underground quarry of Petit-Lanaye inférieure. Temperature has been measured by dataloggers. These measures and the comparison between the different caves contributed to a better understanding of their climates. In the cave of Ramioul, closed by non insulated doors, the air movements are relatively low but there are some heat exchanges between the outside and inside air by conduction through the doors. The cave can be divided into two parts each with a different climatic behaviour. High and dangerous CO2 rates have already been measured in this cave. Rates fluctuate in an irregular way and without any connection with the natural seasonal cycle, and the CO2 origins stay uncertain. The cave of Comblain-au-Pont can be divided into two major parts: one enclosed and the other ventilated. The ventilated region is a “wind tube” during the winter, but it doesn’t reverse in the summer. On a larger scale, this region can be considered as a cold air trap despite its two exits, since it has a descendant morphology. <br />In the underground carry of Petit-Lanaye inférieure, the low number of data doesn’t allow a complete diagnosis of the climate organisation, but can give a first idea for the summer period. We can already distinguish some parts that are more or less influenced by the outside temperature fluctuations, probably in relation with some air movements which organised <br />themselves in a complex way in the labyrinthic galleries network. [less ▲]

Detailed reference viewed: 83 (31 ULg)
Full Text
Peer Reviewed
See detailHistory and clinical features of atypical myopathy in horses in Belgium (2000-2005)
Votion, D. M.; Linden, Annick ULg; Saegerman, Claude ULg et al

in Journal of Veterinary Internal Medicine (2007), 21(6, Nov-Dec), 1380-1391

Background: The emergent nature of atypical myopathy or atypical myoglobinuria (AM) necessitates precise description of its clinical and epidemiologic features. Purpose: To define key features of AM to ... [more ▼]

Background: The emergent nature of atypical myopathy or atypical myoglobinuria (AM) necessitates precise description of its clinical and epidemiologic features. Purpose: To define key features of AM to help practitioners recognize the disease and to advise owners to take preventive measures. Animals: Belgian cases of AM confirmed by histology (CC horses; n = 57) from autumn 2000 to spring 2005 were included in the study. Co-grazing horses (Co-G horses; n = 77) that remained free of any abnormal clinical signs constituted a control croup. Methods: History, environmental characteristics, clinical signs, and laboratory results associated with AM were determined by a retrospective case series study. Results: Young horses in poor or normal body condition were found to be at risk for AM. Pastures were characterized by poor natural drainage and vegetation of low nutritional value. Features of AM were seasonal occurrence, apparent link with weather conditions fie, lack of solar radiation with no heavy frost and an excess of precipitation or relative humidity), sudden onset of clinical signs, and rapid death. Evaluation of serum creatine kinase activity indicated severe muscle destruction in CC horses and subclinical disease in a few Co-G horses. Conclusions: The association of AM with specific environmental conditions and individual animals suggests that young horses should not be pastured on bare premises subject to humidity when the weather has been very wet and cold for several days. Management of AM outbreaks should include control of Co-G horses who are apparently healthy. [less ▲]

Detailed reference viewed: 254 (28 ULg)
Full Text
Peer Reviewed
See detailModélisation de la distribution spatiale des précipitations en Sicile.
Cornet, Yves ULg; Fitschy, C.; Gobbato, O. et al

in Bulletin de la Société Géographique de Liège (2005), 46

Detailed reference viewed: 47 (23 ULg)
Full Text
Peer Reviewed
See detailBrouillards et mauvaises visibilités en Belgique : Analyse menée à partir des observations météorologiques effectuées dans les aéroports civils
Erpicum, Michel ULg; De Swert; Nyssen, Thierry et al

in Publications de l'Association Internationale de Climatologie (2005), 18

Detailed reference viewed: 21 (10 ULg)
Full Text
Peer Reviewed
See detailVariabilité spatio-temporelle de l’albédo. Analyse menée à la résolution métrique
Van Durme, G.; Erpicum, Michel ULg

in Bulletin de la Société Géographique de Liège (2005), 46

Albedo is a climatic factor that has been barely studied and thus is badly understood. However, it has a certain influence on our climate. This influence is especially visible in case of land use changes ... [more ▼]

Albedo is a climatic factor that has been barely studied and thus is badly understood. However, it has a certain influence on our climate. This influence is especially visible in case of land use changes, such as deforestation. The aim of the study presented in this paper is to increase the current knowledge on albedo and the factors that influence it. To achieve this, a field survey was conducted. Not all factors could be studied during the field campaign; among those that were effectively observed, the most important ones – those that were responsible for the biggest changes in albedo – were the development of vegetation, the presence of snow and the daily variation of the height of the sun. [less ▲]

Detailed reference viewed: 115 (14 ULg)