The ocean’s overturning circulation is inherently three-dimensional, yet modern quantitative estimates of the overturning typically represent the subsurface circulation as a two-dimensional, two-cell streamfunction that varies with latitude and depth only. This approach suppresses information about zonal mass and tracer transport. In this article, the authors extend earlier, zonally averaged ov...

We estimated the amount of oil remaining in Prince William Sound, Alaska, 12 yr after the 1989 Exxon Valdez spill to assess its importance as a long-term reservoir of toxic hydrocarbons. We found oil on 78 of 91 beaches randomly selected according to their oiling history. Surface oiling was recorded for randomly placed quadrats, which were then excavated and examined for subsurface oil. The cum...

Using polarized brightness (pB) measurements made by the High Altitude Observatory (HAO) Mauna Loa Mk III K-coronameter, we investigate the daily changes of path-integrated density at 1.15 R,. During 1996, when simultaneous pB and helioseismology data were available, we find that the correlation of pB (at zero time lag and 207 latitude lag) varies with latitude in the same way that the subsurfa...

[1] Data from tomographic surveys make an inverse problem better posed in comparison to the data from a single excitation source. A tomographic survey provides different coverages and perspectives of subsurface heterogeneity: nonfully redundant information of the subsurface. Fusion of these pieces of information expands and enhances the capability of a conventional survey, provides cross valida...

[1] Hyporheic exchange is an ecologically important process, controlling the nutrient supply in the upper sediments and thus benthic habitat quality. Hydraulic exchange at a riffle-pool sequence in the Lahn River, Germany, was analyzed using HEC-RAS to simulate the surface water flow as a boundary for the subsurface flow and MODFLOW, MODPATH, and MT3DMS to reproduce the transport in the subsurf...

In addition to its central role in mediating electron-transfer reactions within all living cells, iron undergoes extracellular redox transformations linked to microbial energy generation through utilization of Fe(II) as a source of chemical energy or Fe(III) as an electron acceptor for anaerobic respiration. These processes permit microbial populations and communities to engage in cyclic couple...

High-resolution tomographic images obtained from crosshole geophysical measurements have the potential to provide valuable information about the geostatistical properties of unsaturated-zone hydrologic-state variables such as moisture content. Under drained or quasi-steady-state conditions, the moisture content will reflect the variation of the physical properties of the subsurface, which deter...

abstract this study was conducted to determine the impacts of plastic mulch, drip irrigation method and different amount of water and their interactions on yield, water use efficiency (wue) and quality characteristic of tomato (mobile cultivar). the study was conducted in torogh agricultural research station, razavi khorasan province. the study was done during 2007-2008. experimental design was...

A timeand depth-dependent, physical-bio-optical model was developed for the California coastal transition zone (CTZ) with the overall objective of understanding and quantifying the processes that contribute to the vertical and temporal development of nutrient and plankton distributions in the CTZ. The model food web components included silicate, nitrate, ammonium, two phytoplankton size fractio...