This paper presents the design and evaluates the performance of a double-walled electrically aspirated radiation shield for thermometers measuring air temperature and its gradients in the atmospheric surface layer. Tests were performed to quantify its solar radiation error and wake production, and to characterize the observer effect of the forced...
In this article, we examine the stochastic characteristics of non-turbulent motions in the stable boundary layer. The behaviour of mesoscale motions in the atmospheric stable boundary layer is poorly understood beyond case studies of unusually well-defined events or monotonic waves. Eight networks of wind observations are analysed in order to...
We present a novel technique to simultaneously measure wind speed (U) at thousands of locations continuously in time based on measurement of velocity-dependent heat transfer from a heated surface. Measuring temperature differences between paired passive and actively heated fiber-optic (AHFO) cables with a distributed temperature sensing system allowed estimation of...
We investigated an alternative means for quantifying daytime ecosystem respiration from eddy-covariance data in three forests with different canopy architecture. Our hypothesis was that the turbulent transport by coherent structures is the main pathway for carrying detectable sub-canopy respiration signals through the canopy. The study extends previously published work by...
We sought to improve net ecosystem exchange (NEE) estimates for a tall, dense, mature Douglas-Fir forest in the Oregon Coast range characterized by weak flows, systematic wind directional shear, and limited turbulent mixing throughout the diurnal period. We used eddy covariance (EC) observations at two levels and concurrent biological measurements...
Turbulence measurements for very stable conditions near the surface are contrasted
among three sites: a high altitude basin during winter with grass or snow-covered
grass, a broad valley with complex agricultural land use, and a more narrow valley that is
influenced by a valley cold pool and cold air drainage....
Full Text:
Stable and Weak-Wind Conditions
Larry Mahrt · Christoph Thomas · Scott Richardson ·
Nelson Seaman
Turbulence measurements for very stable conditions near the surface are contrasted
among three sites: a high altitude basin during winter with grass or snow-covered
grass, a broad valley with complex agricultural land use, and a more narrow valley that is
influenced by a valley cold pool and cold air drainage....
Full Text:
Turbulence for Very Stable and Weak-
Wind Conditions
Larry Mahrt, Christoph Thomas, Scott
Richardson, Nelson
Turbulence measurements for very stable conditions near the surface are contrasted
among three sites: a high altitude basin during winter with grass or snow-covered
grass, a broad valley with complex agricultural land use, and a more narrow valley that is
influenced by a valley cold pool and cold air drainage....
Five years of eddy-covariance and other measurements at a mature ponderosa pine forest and a nearby young plantation are used to contrast the carbon fluxes for long-term averages, seasonal patterns, diel patterns and interannual variability, and to examine the differing responses to water-stress. The mature forest with larger leaf area...
We analyzed 7 years (2002–2008) of micrometeorological and concurrent biological
observations of carbon and water fluxes at a mature ponderosa pine forest in central
Oregon in a semiarid climate. We sought to evaluate the extent that gross primary
productivity, net ecosystem exchange, ecosystem respiration, net primary productivity, net
ecosystem productivity,...