scholarly journals Weather forecast in north-western Greece: RISKMED warnings and verification of MM5 model

2010 ◽  
Vol 10 (2) ◽  
pp. 383-394 ◽  
Author(s):  
A. Bartzokas ◽  
V. Kotroni ◽  
K. Lagouvardos ◽  
C. J. Lolis ◽  
A. Gkikas ◽  
...  
Keyword(s):  
Air Temperature ◽  
Weather Forecasting ◽  
Precipitation Amount ◽  
Warning System ◽  
Weather Forecast ◽  
Early Morning ◽  
Meteorological Model ◽  
Adverse Weather ◽  
North Western ◽  
Western Greece

Abstract. The meteorological model MM5 is applied operationally for the area of north-western Greece for one-year period (1 June 2007–31 May 2008). The model output is used for daily weather forecasting over the area. An early warning system is developed, by dividing the study area in 16 sub-regions and defining specific thresholds for issuing alerts for adverse weather phenomena. The verification of the model is carried out by comparing the model results with observations from three automatic meteorological stations. For air temperature and wind speed, correlation coefficients and biases are calculated, revealing that there is a significant overestimation of the early morning air temperature. For precipitation amount, yes/no contingency tables are constructed for 4 specific thresholds and some categorical statistics are applied, showing that the prediction of precipitation in the area under study is generally satisfactory. Finally, the thunderstorm warnings issued by the system are verified against the observed lightning activity.

scholarly journals Incorporation of Weather Forecasting in Integrated, Biological-Chemical Management of Botrytis cinerea

1997 ◽  
Vol 87 (3) ◽  
pp. 332-340 ◽  
Author(s):  
D. Shtienberg ◽  
Y. Elad
Keyword(s):  
Disease Control ◽  
Botrytis Cinerea ◽  
Biocontrol Agent ◽  
Weather Forecasting ◽  
Warning System ◽  
Weather Forecast ◽  
Commercial Preparation ◽  
Integrated Strategy ◽  
Disease Reduction ◽  
Control Disease

A strategy for integrated biological and chemical control of Botrytis cinerea in nonheated greenhouse vegetables was developed. The biocontrol agent used was a commercial preparation developed from an isolate of Trichoderma harzianum, T39 (Trichodex). Decisions concerning whether to spray the biocontrol agent or a fungicide were made based on a weather-based disease warning system. The integrated strategy (BOTMAN [short for Botrytis manager]) was implemented as follows: when slow or no disease progress was expected, no spraying was needed; when an outbreak of epidemics was expected, use of a chemical fungicide was recommended; in all other cases, application of T. harzianum T39 was recommended. Future weather information (a 4-day weather forecast provided by the Israel Weather Forecast Service) was more useful for disease warnings than immediate past weather. The integrated strategy was compared with weekly applications of fungicide in 11 experiments conducted over 3 years in greenhouse-grown tomato and cucumber. Disease reduction in the integrated strategy (63.9 ± 3.0%) did not differ significantly (P < 0.05) from the fungicide-only treatment (70.1 ± 3.6%). The number of fungicide sprays in the integrated strategy ranged from 2 to 7 (mean 4.2) compared to 7 to 13 (mean 10.5) in the fungicide treatment. The integrated strategy averaged 5.9 sprays of T. harzianum T39. For the integrated strategy, one treatment omitted use of T. harzianum T39 to estimate the contribution of this agent to disease control. Disease reduction in that treatment (49.1 ± 4.8%) was significantly (P < 0.05) inferior to the combined chemical and biological strategy, indicating that the T. harzianum T39 sprays had a measurable effect on disease control.

scholarly journals Earthquake Source Investigation of the Kanallaki, March 2020 Sequence (North-Western Greece) Based on Seismic and Geodetic Data

2021 ◽  
Vol 13 (9) ◽  
pp. 1752
Author(s):  
Nikos Svigkas ◽  
Anastasia Kiratzi ◽  
Andrea Antonioli ◽  
Simone Atzori ◽  
Cristiano Tolomei ◽  
...  
Keyword(s):  
Surface Deformation ◽  
Detailed Knowledge ◽  
Eurasian Plate ◽  
Distribution Models ◽  
Active Deformation ◽  
Strong Earthquakes ◽  
Seismic Waveforms ◽  
Northwestern Greece ◽  
North Western ◽  
Western Greece

The active collision of the Apulian continental lithosphere with the Eurasian plate characterizes the tectonics of the Epirus region in northwestern Greece, invoking crustal shortening. Epirus has not experienced any strong earthquakes during the instrumental era and thus there is no detailed knowledge of the way the active deformation is being expressed. In March 2020, a moderate size (Mw 5.8) earthquake sequence occurred close to the Kanallaki village in Epirus. The mainshock and major aftershock focal mechanisms are compatible with reverse faulting, on NNW-ESE trending nodal planes. We measure the coseismic surface deformation using radar interferometry and investigate the possible fault geometries based on seismic waveforms and InSAR data. Slip distribution models provide good fits to both nodal planes and cannot resolve the fault plane ambiguity. The results indicate two slip episodes for a N337° plane dipping 37° to the east and a single slip patch for a N137° plane dipping 43° to 55° to the west. Even though the area of the sequence is very close to the triple junction of western Greece, the Kanallaki 2020 activity itself seems to be distinct from it, in terms of the acting stresses.

Prevalence of Staphylococcus aureus and of methicillin-resistant S. aureus (MRSA) along the production chain of dairy products in north-western Greece

2018 ◽  
Vol 69 ◽  
pp. 43-50 ◽  
Author(s):  
Panagiotis Papadopoulos ◽  
Theofilos Papadopoulos ◽  
Apostolos S. Angelidis ◽  
Evridiki Boukouvala ◽  
Antonios Zdragas ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Products ◽  
Production Chain ◽  
Methicillin Resistant ◽  
North Western ◽  
Western Greece

scholarly journals A Mental Models Study of Hurricane Forecast and Warning Production, Communication, and Decision-Making*

2016 ◽  
Vol 8 (2) ◽  
pp. 111-129 ◽  
Author(s):  
Ann Bostrom ◽  
Rebecca E. Morss ◽  
Jeffrey K. Lazo ◽  
Julie L. Demuth ◽  
Heather Lazrus ◽  
...  
Keyword(s):  
Risk Communication ◽  
Mental Models ◽  
Warning System ◽  
Weather Forecast ◽  
Extreme Weather ◽  
South Florida ◽  
Extreme Weather Events ◽  
Research Approach ◽  
Action Context ◽  
Risk Decision

Abstract The study reported here explores how to enhance the public value of hurricane forecast and warning information by examining the entire warning process. A mental models research approach is applied to address three risk management tasks critical to warnings for extreme weather events: 1) understanding the risk decision and action context for hurricane warnings, 2) understanding the commonalities and conflicts in interpretations of that context and associated risks, and 3) exploring the practical implications of these insights for hurricane risk communication and management. To understand the risk decision and action context, the study develops a decision-focused model of the hurricane forecast and warning system on the basis of results from individual mental models interviews with forecasters from the National Hurricane Center (n = 4) and the Miami–South Florida Weather Forecast Office (n = 4), media broadcasters (n = 5), and public officials (n = 6), as well as a group decision-modeling session with a subset of the forecasters. Comparisons across professionals reveal numerous shared perceptions, as well as some critical differences. Implications for improving extreme weather event forecast and warning systems and risk communication are threefold: 1) promote thinking about forecast and warning decisions as a system, with informal as well as formal elements; 2) evaluate, coordinate, and consider controlling the proliferation of forecast and warning information products; and 3) further examine the interpretation and representation of uncertainty within the hurricane forecast and warning system as well as for users.

scholarly journals <i>Brief communication</i> "A statistical validation for the cycles found in air temperature data using a Morlet wavelet-based method"

2010 ◽  
Vol 17 (3) ◽  
pp. 269-272 ◽  
Author(s):  
S. Nicolay ◽  
G. Mabille ◽  
X. Fettweis ◽  
M. Erpicum
Keyword(s):  
Air Temperature ◽  
Climate Model ◽  
Surface Air Temperature ◽  
Weather Forecast ◽  
Temperature Data ◽  
Temperature Time Series ◽  
Climatic Data ◽  
Statistical Validation ◽  
Confidence Levels ◽  
Temperature Time

Abstract. Recently, new cycles, associated with periods of 30 and 43 months, respectively, have been observed by the authors in surface air temperature time series, using a wavelet-based methodology. Although many evidences attest the validity of this method applied to climatic data, no systematic study of its efficiency has been carried out. Here, we estimate confidence levels for this approach and show that the observed cycles are significant. Taking these cycles into consideration should prove helpful in increasing the accuracy of the climate model projections of climate change and weather forecast.

scholarly journals Satellite observations of changes in snow-covered land surface albedo during spring in the Northern Hemisphere

2015 ◽  
Vol 9 (5) ◽  
pp. 1879-1893 ◽  
Author(s):  
K. Atlaskina ◽  
F. Berninger ◽  
G. de Leeuw
Keyword(s):  
Snow Cover ◽  
Northern Hemisphere ◽  
Air Temperature ◽  
Land Surface ◽  
Surface Albedo ◽  
Vegetation Index ◽  
Precipitation Amount ◽  
Snow Cover Fraction ◽  
Air Temperatures ◽  
Moderate Resolution Imaging Spectroradiometer

Abstract. Thirteen years of Moderate Resolution Imaging Spectroradiometer (MODIS) surface albedo data for the Northern Hemisphere during the spring months (March–May) were analyzed to determine temporal and spatial changes over snow-covered land surfaces. Tendencies in land surface albedo change north of 50° N were analyzed using data on snow cover fraction, air temperature, vegetation index and precipitation. To this end, the study domain was divided into six smaller areas, based on their geographical position and climate similarity. Strong differences were observed between these areas. As expected, snow cover fraction (SCF) has a strong influence on the albedo in the study area and can explain 56 % of variation of albedo in March, 76 % in April and 92 % in May. Therefore the effects of other parameters were investigated only for areas with 100 % SCF. The second largest driver for snow-covered land surface albedo changes is the air temperature when it exceeds a value between −15 and −10 °C, depending on the region. At monthly mean air temperatures below this value no albedo changes are observed. The Enhanced Vegetation Index (EVI) and precipitation amount and frequency were independently examined as possible candidates to explain observed changes in albedo for areas with 100 % SCF. Amount and frequency of precipitation were identified to influence the albedo over some areas in Eurasia and North America, but no clear effects were observed in other areas. EVI is positively correlated with albedo in Chukotka Peninsula and negatively in eastern Siberia. For other regions the spatial variability of the correlation fields is too high to reach any conclusions.

scholarly journals Investigating late Holocene variations in hydroclimate and the stable isotope composition of precipitation using southern South American peatlands: an hypothesis

2012 ◽  
Vol 8 (5) ◽  
pp. 1457-1471 ◽  
Author(s):  
T. J. Daley ◽  
D. Mauquoy ◽  
F. M. Chambers ◽  
F. A. Street-Perrott ◽  
P. D. M. Hughes ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Air Temperature ◽  
Regional Differences ◽  
Late Holocene ◽  
Isotope Composition ◽  
Precipitation Amount ◽  
Surface Air Temperature ◽  
Global Network ◽  
Stable Isotope Composition ◽  
Δd And Δ18o

Abstract. Ombrotrophic raised peatlands provide an ideal archive for integrating late Holocene records of variations in hydroclimate and the estimated stable isotope composition of precipitation with recent instrumental measurements. Modern measurements of mean monthly surface air temperature, precipitation, and δD and δ18O-values in precipitation from the late twentieth and early twenty-first centuries provide a short but invaluable record with which to investigate modern relationships between these variables, thereby enabling improved interpretation of the peatland palaeodata. Stable isotope data from two stations in the Global Network for Isotopes in Precipitation (GNIP) from southern South America (Punta Arenas, Chile and Ushuaia, Argentina) were analysed for the period 1982 to 2008 and compared with longer-term meteorological data from the same locations (1890 to present and 1931 to present, respectively). δD and δ18O-values in precipitation have exhibited quite different trends in response to local surface air temperature and precipitation amount. At Punta Arenas, there has been a marked increase in the seasonal difference between summer and winter δ18O-values. A decline in the deuterium excess of summer precipitation at this station was associated with a general increase in relative humidity at 1000 mb over the surface of the Southeast Pacific Ocean, believed to be the major vapour source for the local precipitation. At Ushuaia, a fall in δ18O-values was associated with an increase in the mean annual amount of precipitation. Both records are consistent with a southward retraction and increase in zonal wind speed of the austral westerly wind belt. These regional differences, observed in response to a known driver, should be detectable in peatland sites close to the GNIP stations. Currently, insufficient data with suitable temporal resolution are available to test for these regional differences over the last 3000 yr. Existing peatland palaeoclimate data from two sites near Ushuaia, however, provide evidence for changes in the late Holocene that are consistent with the pattern observed in modern observations.

scholarly journals Weather conditions and weather forecast on the planets of the solar system based on the behavior of Rossby waves

2010 ◽  
Vol 90 (1) ◽  
pp. 135-144
Author(s):  
Milivoj Gavrilov ◽  
Lazar Lazic ◽  
Jasmina Djordjevic
Keyword(s):  
Solar System ◽  
Rossby Waves ◽  
Weather Forecasting ◽  
Weather Forecast ◽  
Weather Conditions ◽  
Relative Movement ◽  
Rotating Fluids ◽  
Atmospheric Processes ◽  
Rotation System ◽  
Dominant Influence

Out of all atmospheric processes on the planets of the Solar System, special attention will be devoted here to leading circulation of planetary or global scales, known as Rossby waves. These waves occur in all rotating fluids that have relative movement to the rotation system. Rossby waves exert dominant influence on so-called global weather. Based on the knowledge of some properties of Rossby waves are made approximate analysis of weather conditions on the planets of the Solar System. Also, these considerations can serve as an introduction to weather forecasting on the planet. .

Sign in / Sign up

Export Citation Format

Share Document