Three decades of weather records at meteorological stations near Death Valley National Park are analyzed in an attempt to gauge the frequency of conditions that might form and erase the famous trails of wind-blown rocks in the mud of Racetrack Playa. Trail formation requires the playa to be wet, followed by strong winds and/or freezing conditions. Weather records are compared with a limited set...

During the summer of 1997, water samples were collected and analyzed for pesticides from 32 playa lakes of the High Plains that receive drainage from both cotton and corn agriculture in West Texas. The major cotton herbicides detected in the water samples were diuron, fluometuron, metolachlor, norflurazon, and prometryn. Atrazine and propazine, corn and sorghum herbicides, were also routinely d...

In the desert of Abarkoh Basin, Central Iran, the influence of playa-lake level fluctuations on recent sedimentation mode of a terminal ephemeral fluvial-fan system and adjacent lacustrine/aeolian sediments of a playa fringe environment has been investigated. The surface geomorphology-sedimentology and its relationship with shallow subsurface sediments along a >25 km transect, has been studied....

[1] During the Ice in Clouds Experiment‐Layer Clouds (ICE‐L), dry lakebed, or playa, salts from the Great Basin region of the United States were observed as cloud nuclei in orographic wave clouds over Wyoming. Using a counterflow virtual impactor in series with a single‐particle mass spectrometer, sodium‐potassium‐magnesium‐calcium‐chloride salts were identified as residues of cloud droplets. I...

This paper introduces Playa, a high-level user interface layer for composing algorithms for complex multiphysics problems out of objects from other Trilinos packages. Among other features, Playa provides very high-performance overloaded operators implemented through an expression template mechanism. In this paper, we give an overview of the central Playa objects from a user’s perspective, show ...

Studies of ancient Egyptian religion have examined texts for evidence of cattle worship, but the picture given by the texts is incomplete. Mortuary patterns, ceremonial buildings, grave goods, ceramics and other remains also contain evidence of cattle worship and underline its importance to early Egypt. The recently discovered cattle tumuli at Nabta Playa in the Western Desert are identified he...

The engraved trails of rocks on the nearly flat, dry mud surface of Racetrack Playa, Death Valley National Park, have excited speculation about the movement mechanism since the 1940s. Rock movement has been variously attributed to high winds, liquid water, ice, or ice flotation, but has not been previously observed in action. We recorded the first direct scientific observation of rock movements...

Playa wetlands are important areas of soil organic carbon and nutrient storage in drylands. We conducted this study to assess how catchment biophysical variables control soil organic carbon and nitrogen in playas and how playas function differently than upland ecosystems. We found that playa organic carbon and nitrogen corresponded primarily with catchment vegetation cover and secondarily with ...