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Pedro A. Jiménez, Jordi Vilà-Guerau de Arellano, J. Fidel González-Rouco, Jorge Navarro, Juan P. Montávez, Elena García-Bustamante, and Jimy Dudhia

1. Introduction Extreme weather situations produce strong impacts on humankind activities ( Easterling et al. 2000 ). The drought and heat wave that affected Europe in the summer of 2003 produced enormous socioeconomic implications (e.g., Vandertorren et al. 2004 ; Schär and Jendritzky 2004 ). The anticyclonic conditions and a deficit of soil moisture availability that already affected more than 80% of the continent in springtime ( Loew et al. 2009 ) led to the extremely high surface air

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Janni Yuval and Yohai Kaspi

warming temperature changes, temperature modifications that are quantitatively similar to the projections obtained from phase 5 of the Coupled Model Intercomparison Project (CMIP5) are used to modify a chosen reference state. To consider a realistic reference temperature, the reference relaxation temperature is chosen to be the zonal and wintertime (DJF) mean temperature obtained from the European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis (ERA-Interim) dataset between the

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Daniel S. Wilks

.g., Pérez-Hernández and Joyce 2014 ; Ortega et al. 2015 ; Wang et al. 2015 ; Feng et al. 2016 ). However, Rule N is only strictly valid for the hypothesis test involving the leading eigenvalue, which amounts to testing the null hypothesis that the signal subspace is null. The result is that Rule N is usually conservative, meaning that it retains too few components. This paper proposes a modification of Rule N for PCA truncation that is based on several relatively recent results from the statistics

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Julio Buchmann, Jan Paegle, Lawrence E. Buja, and Robert E. Dickinson

. However, in more recent years, there has been aneven greater research emphasis upon correlations oftropical and extratropical weather with SSTA of thetropical Pacific Ocean associated with the El Nifio,Southern Oscillation (ENSO). Trenberth et al. (1988)and Kousky et al. (1984) present recent observationalstudies of ENSO related signals. Negative SSTA anomalies were observed over muchof the equatorial east Pacific during the droughts of1986 and 1988, with the latter becoming notable duringthe

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Michael Chenoweth

tropical cyclone tracks from HURDAT2 and compared with the new tracks from the new compilation. This year is chosen as it has features that are typical of most other years: 1) two storms from HURDAT2 (storms 1 and 4) that are omitted; 2) it benefits from daily weather maps for the month of August ( Toynbee 1878 ), which allowed for modifications of the track, intensity, and extratropical transition of storm 2 in HURDAT2; and 3) it includes new storms not in HURDAT2. Fig . 2. North Atlantic tropical

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Christophe Cassou, Laurent Terray, and Adam S. Phillips

1. Link between summer North Atlantic weather regimes and extreme warm days Europe has been rapidly warming up since the late 1970s ( Jones and Moberg 2003 ). Concurrently, extreme weather events have become more frequent over most of the continent ( Klein Tank and Können 2003 ). The last in date is the summer 2003 heat wave (e.g., Schär et al. 2004 ) responsible for massive overmortality and tremendous socioeconomic impacts in many European countries. Large-scale synoptic pressure systems

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John A. Flueck and Timothy J. Brown

appears to be considerable skepticism toward any proposed solar-weather relation, and it often seems thatthe field is dominated by two groups, believers andnonbelievers, much like it was over 100 years ago(Young 1896; Eddy 1983). It is interesting to note thatthis same polarization has existed in another area ofatmospheric science (i.e., weather modification, Neyman 1967 ), but the situation is now changing as bettermeasurements and improved scientific practices arebeing adopted (e.g., National

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Christophe Cassou, Laurent Terray, James W. Hurrell, and Clara Deser

the spatial structure of the anomalies are the same, but of opposite polarity. Interest in this nonlinear interpretation of atmospheric variability has been growing, finding some applications within climate frameworks ( Palmer 1999 ) as opposed to weather issues where this approach has been more commonly used. The nonlinear paradigm is based on the identification of “attractors” that correspond to weather or climate regimes ( Lorenz 1963 ) being defined as peaks in the probability density

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M. A. Jenkins, W. C. Wong, K. Higuchi, and J. L. Knox

792JOURNAL OF CLIMATEVOLUME 7Precipitation at Ocean Weather Station "P" M. A. JENKINS AND W. C. WONGDepartment of Earth and Atmospheric Sciences, York University, North York, Ontario, Canada K. HIGUCHIClimate Diagnostics Research Group, Atmospheric Environment Service, Downsview, Ontario, Canada J. L. KNOXToronto, Ontario, Canada(Manuscript received I April 1993, in final form 10 August 1993)ABSTRAC'TF This paper examines the 27-yr record of

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Nicholas A. Bond and Meghan F. Cronin

observational study of atmospheric boundary layer (ABL) modification during periods of intense surface heating and moistening ( Lenschow and Agee 1976 ). While the weather pattern for this situation is well appreciated in a general sense, little attention has been paid to the opposite situation, that is, to periods of anomalous downward surface heat fluxes. Even less is known about the weather patterns associated with anomalous surface heat fluxes in the summer. It might be expected that the net heat fluxes

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