A hitherto unexplained feature of electromagnetic simulations of ion temperature gradient turbulence is the apparent failure of the transport levels to saturate for certain parameters; this effect, termed here nonzonal transition, has been referred to as the high-β runaway. The resulting large heat fluxes are shown to be a consequence of reduced zonal flow activity, brought on by magnetic field perturbations shorting out flux surfaces.
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http://dx.doi.org/10.1103/PhysRevLett.110.155005 | DOI Listing |
Front Microbiol
December 2024
Department of Earth Sciences, University of Southern California, Los Angeles, CA, United States.
Microbial activity in the deep continental subsurface is difficult to measure due to low cell densities, low energy fluxes, cryptic elemental cycles and enigmatic metabolisms. Nonetheless, direct access to rare sample sites and sensitive laboratory measurements can be used to better understand the variables that govern microbial life underground. In this study, we sampled fluids from six boreholes at depths ranging from 244 m to 1,478 m below ground at the Sanford Underground Research Facility (SURF), a former goldmine in South Dakota, United States.
View Article and Find Full Text PDFGlobal Biogeochem Cycles
January 2025
Heat and drought events are increasing in frequency and intensity, posing significant risks to natural and agricultural ecosystems with uncertain effects on the net ecosystem CO exchange (NEE). The current Vegetation Photosynthesis and Respiration Model (VPRM) was adjusted to include soil moisture impacts on the gross ecosystem exchange (GEE) and respiration ( ) fluxes to assess the temporal variability of NEE over south-western Europe for 2001-2022. Warming temperatures lengthen growing seasons, causing an increase in GEE, which is mostly compensated by a similar increment in .
View Article and Find Full Text PDFSci Rep
December 2024
Climate and Global Dynamics Laboratory, NSF National Center for Atmospheric Research, 1850 Table Mesa Drive, Boulder, CO, 80305, USA.
The warm Western Boundary Currents (WBCs) and their zonal extensions are persistent, deep, strong and narrow oceanic currents. They are known to anchor and energize the Extra-Tropical storm tracks by frontal thermal air-sea interactions. However, even in the latest generation of climate models, WBCs are characterized by large biases, and both the present storm-track activity and its recent intensification are poorly estimated.
View Article and Find Full Text PDFSurv Geophys
April 2024
Department of Atmospheric and Oceanic Science, University of Wisconsin, Madison, WI 53706 USA.
Accurate diagnosis of regional atmospheric and surface energy budgets is critical for understanding the spatial distribution of heat uptake associated with the Earth's energy imbalance (EEI). This contribution discusses frameworks and methods for consistent evaluation of key quantities of those budgets using observationally constrained data sets. It thereby touches upon assumptions made in data products which have implications for these evaluations.
View Article and Find Full Text PDFSurv Geophys
July 2023
Applied Physics Laboratory, University of Washington, Seattle, WA 98105 USA.
The global seasonal cycle of energy in Earth's climate system is quantified using observations and reanalyses. After removing long-term trends, net energy entering and exiting the climate system at the top of the atmosphere (TOA) should agree with the sum of energy entering and exiting the ocean, atmosphere, land, and ice over the course of an average year. Achieving such a balanced budget with observations has been challenging.
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