scholarly journals Heavy precipitation episodes and cosmic rays variation

2006 ◽  
Vol 7 ◽  
pp. 157-161 ◽  
Author(s):  
A. Mavrakis ◽  
S. Lykoudis
Keyword(s):  
Cosmic Rays ◽  
Data Processing ◽  
Statistical Methods ◽  
Water Availability ◽  
Temporal Correlation ◽  
Precipitable Water ◽  
Heavy Precipitation ◽  
Daily Basis ◽  
Different Response ◽  
Climatic Characteristics

Abstract. In this paper an attempt is made to investigate the possible temporal correlation between heavy precipitation episodes and cosmic rays' activity, on various time scales. Cosmic rays measurements are sparse and cover less extended periods than those of precipitation. Precipitation is largely influenced by local climatic and even physiographic conditions, while cosmic rays' distribution is far more uniform over an area. Thus, in an effort to cover a larger range of climatic characteristics, each cosmic rays station was correlated with several nearby precipitation stations. Selected statistical methods were employed for the data processing. The analysis was preformed on annual, seasonal, monthly and daily basis whenever possible. Wet and dry regions and/or seasons seem to present a different response of precipitation to cosmic rays variations. Also Forbush decreases in most cases will not lead to heavy precipitation, yet this might be sensitive to precipitable water availability.

Prediction of daily heavy precipitation in a lowland area using GPS and surface weather data

2008 ◽  
Vol 8 (1) ◽  
pp. 101-106
Author(s):  
Makito Mori ◽  
Kazuaki Hiramatsu ◽  
Masayoshi Harada
Keyword(s):  
Water Vapor ◽  
Meteorological Data ◽  
Precipitable Water ◽  
Heavy Precipitation ◽  
Daily Basis ◽  
Weather Data ◽  
Surface Weather ◽  
Lowland Area ◽  
Infinite Height ◽  
Precipitation Events

Recent progress in GPS technology has enabled us to estimate the total amount of water vapor in an atmospheric column with infinite height as ’GPS-derived precipitable water vapor’ (GPS-PWV). In the present study, we analyzed the GPS and meteorological data obtained in Saga Plain, in northern Kyushu, Japan. An attempt was made to predict heavy precipitation (≥50 mm d−1) on a daily basis using the analyzed relations between surface temperature and GPS-PWV. Several features were revealed that were associated with the daily heavy precipitation at the study area. An index was made to predict heavy precipitation on a daily basis. Applying the index to observations, we obtained acceptable results of the prediction. It is suggested that GPS is useful for predicting heavy precipitation events.

scholarly journals Changes in Temperature and Precipitation Extremes in Superparameterized CAM in Response to Warmer SSTs

2017 ◽  
Vol 30 (24) ◽  
pp. 9827-9845 ◽  
Author(s):  
Xin Zhou ◽  
Marat F. Khairoutdinov
Keyword(s):  
Large Scale ◽  
Rain Rate ◽  
Precipitable Water ◽  
Heavy Precipitation ◽  
Global Scale ◽  
Precipitation Extremes ◽  
Temperature And Precipitation ◽  
Hourly Data ◽  
Cloud Resolving Model ◽  
Cold Extremes

Subdaily temperature and precipitation extremes in response to warmer SSTs are investigated on a global scale using the superparameterized (SP) Community Atmosphere Model (CAM), in which a cloud-resolving model is embedded in each CAM grid column to simulate convection explicitly. Two 10-yr simulations have been performed using present climatological sea surface temperature (SST) and perturbed SST climatology derived from the representative concentration pathway 8.5 (RCP8.5) scenario. Compared with the conventional CAM, SP-CAM simulates colder temperatures and more realistic intensity distribution of precipitation, especially for heavy precipitation. The temperature and precipitation extremes have been defined by the 99th percentile of the 3-hourly data. For temperature, the changes in the warm and cold extremes are generally consistent between CAM and SP-CAM, with larger changes in warm extremes at low latitudes and larger changes in cold extremes at mid-to-high latitudes. For precipitation, CAM predicts a uniform increase of frequency of precipitation extremes regardless of the rain rate, while SP-CAM predicts a monotonic increase of frequency with increasing rain rate and larger change of intensity for heavier precipitation. The changes in 3-hourly and daily temperature extremes are found to be similar; however, the 3-hourly precipitation extremes have a significantly larger change than daily extremes. The Clausius–Clapeyron scaling is found to be a relatively good predictor of zonally averaged changes in precipitation extremes over midlatitudes but not as good over the tropics and subtropics. The changes in precipitable water and large-scale vertical velocity are equally important to explain the changes in precipitation extremes.

scholarly journals Analysis of intense rainfall events on Madeira Island during the 2009/2010 winter

2012 ◽  
Vol 12 (7) ◽  
pp. 2225-2240 ◽  
Author(s):  
F. T. Couto ◽  
R. Salgado ◽  
M. J. Costa
Keyword(s):  
Precipitable Water ◽  
Heavy Precipitation ◽  
Rain Gauge ◽  
Horizontal Resolution ◽  
Pressure System ◽  
Orographic Effects ◽  
Madeira Island ◽  
High Rainfall ◽  
High Precipitation Events ◽  
Precipitation Events

Abstract. This paper constitutes a step towards the understanding of some characteristics associated with high rainfall amounts and flooding on Madeira Island. The high precipitation events that occurred during the winter of 2009/2010 have been considered with three main goals: to analyze the main atmospheric characteristics associated with the events; to expand the understanding of the interaction between the island and the atmospheric circulations, mainly the effects of the island on the generation or intensification of orographic precipitation; and to evaluate the performance of high resolution numerical modeling in simulating and forecasting heavy precipitation events over the island. The MESO-NH model with a horizontal resolution of 1 km is used, as well as rain gauge data, synoptic charts and measurements of precipitable water obtained from the Atmospheric InfraRed Sounder (AIRS). The results confirm the influence of the orographic effects on precipitation over Madeira as well as the tropical–extratropical interaction, since atmospheric rivers were detected in six out of the seven cases analyzed, acting as a low level moisture supplier, which together with the orographic lifting induced the high rainfall amounts. Only in one of the cases the presence of a low pressure system was identified over the archipelago.

scholarly journals Statistical methods for analysis of multi-harvest data from perennial pasture variety selection trials

2015 ◽  
Vol 66 (9) ◽  
pp. 947 ◽  
Author(s):  
Joanne De Faveri ◽  
Arūnas P. Verbyla ◽  
Wayne S. Pitchford ◽  
Shoba Venkatanagappa ◽  
Brian R. Cullis
Keyword(s):  
Statistical Methods ◽  
Temporal Correlation ◽  
Field Trials ◽  
Model Fit ◽  
Natural Sources ◽  
Variety Selection ◽  
Sources Of Variation ◽  
Harvest Data ◽  
Insight Into

Variety selection in perennial pasture crops involves identifying best varieties from data collected from multiple harvest times in field trials. For accurate selection, the statistical methods for analysing such data need to account for the spatial and temporal correlation typically present. This paper provides an approach for analysing multi-harvest data from variety selection trials in which there may be a large number of harvest times. Methods are presented for modelling the variety by harvest effects while accounting for the spatial and temporal correlation between observations. These methods provide an improvement in model fit compared to separate analyses for each harvest, and provide insight into variety by harvest interactions. The approach is illustrated using two traits from a lucerne variety selection trial. The proposed method provides variety predictions allowing for the natural sources of variation and correlation in multi-harvest data.

scholarly journals Moisture transport in observations and reanalyses as a proxy for snow accumulation in East Antarctica

2019 ◽  
Vol 13 (2) ◽  
pp. 413-425 ◽  
Author(s):  
Ambroise Dufour ◽  
Claudine Charrondière ◽  
Olga Zolina
Keyword(s):  
Moisture Transport ◽  
Precipitable Water ◽  
Daily Basis ◽  
Snow Accumulation ◽  
East Antarctica ◽  
Moisture Convergence ◽  
Sea Level Changes ◽  
Moisture Fluxes ◽  
Eddy Fluxes

Abstract. Atmospheric moisture convergence on ice sheets provides an estimate of snow accumulation, which is critical to quantifying sea-level changes. In the case of East Antarctica, we computed moisture transport from 1980 to 2016 in five reanalyses and in radiosonde observations. Moisture convergence in reanalyses is more consistent than net precipitation but still ranges from 72 to 96 mm yr−1 in the four most recent reanalyses, ERA-Interim, NCEP CFSR, JRA 55 and MERRA 2. The representation of long-term variability in reanalyses is also inconsistent, which justified resorting to observations. Moisture fluxes are measured on a daily basis via radiosondes launched from a network of stations surrounding East Antarctica. Observations agree with reanalyses on the major role of extreme advection events and transient eddy fluxes. Although assimilated, the observations reveal processes that reanalyses cannot model, some due to a lack of horizontal and vertical resolution, especially the oldest, NCEP DOE R2. Additionally, the observational time series are not affected by new satellite data unlike the reanalyses. We formed pan-continental estimates of convergence by aggregating anomalies from all available stations. We found statistically significant trends neither in moisture convergence nor in precipitable water.

Performance Analysis of OWC Using NOP Technique

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Ghanendra Kumar ◽  
Chakresh Kumar
Keyword(s):  
Performance Analysis ◽  
Statistical Methods ◽  
Expectation Maximization ◽  
Communication System ◽  
Review Paper ◽  
Temporal Correlation ◽  
Step Algorithm

AbstractIn this review paper, the turbulence of the channel through which the light photons are scattered has been modeled. The channel here is essentially the lower lithosphere. A two-step algorithm called the Method of Expectation–Maximization has been used for the analysis and calculations of the parameters involved. Statistical methods have been used to check temporal correlation and the tolerance of the communication system involved. The simulations and results have been presented and the conclusions show decent performance. The approaches have been applied to the UV scattering channel experiment, NLOS experiment and for link gain at a distance of 0.5 km.

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