Groundwater recharge zones mapping using GIS: a case study in Southern part of Jordan Valley,Jordan

This paper aims at mapping the potential groundwater recharge zones in the southern part of Jordan Valley (JV). This area is considered as the most important part for agricultural production in Jordan. The methodology adopted in this study is based on utilizing the open ended SLUGGER-DQL score model, which was developed by Raymond et al (2009). Geographic information systems were used in this study to build up the different layers of this model and to create the potential groundwater recharge zones. Based on the generated SLUGGER-DQL potential map, it was found that about 70.8 % of the investigated area was categorized as high potential for groundwater recharge, 18.7 % as moderate, and 10.5 % as low potential for groundwater recharge. To validate the model results, sensitivity analysis was carried out to assess the influence of each model parameter on the obtained results. Based on this analysis, it was found that the slope parameter (S) is the most sensitive parameter among SLUGGER-DQL model parameters, followed by water level in summer (L), well density (D), water quality (Q), runoff availability (R), land use/land cover, geology (GE), whereas the lowest sensitive parameter is the geology parameter (GE). Moreover, the parameters R, D, and Q show the lowest effective weights. The effective weight for each parameter was found to differ from the assigned theoretical weight by SLUGGER-DQL index model.     

On non-Gaussian SST variability in the Gulf Stream and other strong currents

This paper examines the physics of observed non-Gaussian sea surface temperature (SST) anomaly variability in the Gulf Stream system in a recently developed stochastic framework. It is first shown from a new high-resolution observational data set that the Gulf Stream system is very clearly visible as a band of negative skewness all the way from Florida, over Cape Hatteras, to the central North Atlantic. To get an idea about the detailed non-Gaussian variability along the Gulf Stream, probability density functions are calculated at several locations. One important observational result of this study is that the non-Gaussian tails of SST variability in the Gulf Stream system follow a power-law distribution. The study then shows that the observed non-Gaussianity is consistent with stochastic advection of SST anomalies in an idealized zonal current. In addition, stochastic advection is compatible with the observed northward eddy heat flux in the Gulf Stream, providing a new dynamical view at the heat balance in strong currents.