Continuous measurements of the surface energy balance components (net radiation Rn, sensible heat flux H, latent heat flux LE, ground heat flux G, and CO2 fluxes began in early June of 1995 at the Little Washita Watershed, near Chickasha, Oklahoma. A severe drought during …
Journal: Agricultural And Forest Meteorology, Volume 106 (3): 205-214 (2001). DOI: 10.1016/s0168-1923(00)00213-6 Sites: US-LWW
An analysis of boundary layer cumulus clouds and their impact on land surface–atmosphere exchange is presented. Seasonal trends indicate that in response to increasing insolation and sensible heat flux, both the mixed-layer height (zi) …
Journal: Journal Of Climate, Volume 14 (2): 180-197 (2001). DOI: 10.1175/1520-0442(2001)013<0180:BLCAVA>2.0.CO;2 Sites: US-Ha1
Respiration rates of heterogeneous forest canopies arise from needles, stems, roots and soil microbes. To assess the temporal and spatial variation in respiration rates of these components in a heterogeneous ponderosa pine forest canopy, and the processes that control these fluxes, we conducted an intensive field study during …
Journal: Agricultural And Forest Meteorology, Volume 110 (1): 27-43 (2001). DOI: 10.1016/s0168-1923(01)00279-9 Sites: US-Me5
We investigated key factors controlling mass and energy exchange by a young (6-year-old) ponderosa pine (Pinus ponderosa Laws.) plantation on the west side of the Sierra Nevada Mountains and an old-growth ponderosa pine forest (mix of 45- and 250-year-old trees) on the east side of the Cascade Mountains, from June through …
Journal: Tree Physiology, Volume 21 (5): 299-308 (2001). DOI: 10.1093/treephys/21.5.299 Sites: US-Me4, US-Me5
Time series of mixed layer depth, zi, and stable boundary layer height from March through October of 1998 are derived from a 915-MHz boundary layer profiling radar and CO2 mixing ratio measured from a 447-m tower in northern Wisconsin. Mixed layer depths from the profiler are in good agreement with radiosonde …
Journal: Journal Of The Atmospheric Sciences, Volume 58 (10): 1288-1299 (2001). DOI: 10.1175/1520-0469(2001)058<1288:LTOOTD>2.0.CO;2 Sites: US-PFa
We present the first canopy-scale, continuous, long-term flux measurements of a suite of oxygenated volatile organic compounds (OVOCs). Fluxes were measured above a ponderosa pine plantation, adjacent to …
Journal: Journal Of Geophysical Research: Atmospheres, Volume 106 (D3): 3111-3123 (2001). DOI: 10.1029/2000jd900592 Sites: US-Blo
The advent of long-term studies on CO2 and water vapor exchange provides us with new information on how the atmosphere and biosphere interact. Conventional time series analysis suggests that temporal fluctuations of weather variables and mass and energy flux densities occur on numerous time scales. The time scales …
Journal: Agricultural And Forest Meteorology, Volume 107 (1): 1-27 (2001). DOI: 10.1016/s0168-1923(00)00228-8 Sites: US-WBW
This study is the first to contrast two similarity theory methods, the flux variance and the half-order time derivative, over a wide range of atmospheric stability and surface roughness conditions. These …
Journal: Water Resources Research, Volume 37 (9): 2333-2343 (2001). DOI: 10.1029/2001wr900021 Sites: US-Dk3
The thermal environment of clear-cut, partially cut, and uncut forest sites in northern Wisconsin are examined for a warm year and a cool year. Temperatures at 0.5 m above and 0.05 m below ground, as well as base 5°C heat sums are computed for each site between May and …
Journal: Agricultural And Forest Meteorology, Volume 106 (4): 331-336 (2001). DOI: 10.1016/s0168-1923(00)00220-3 Sites: US-WCr
Methodology for determining fluxes of CO2 and H2O vapor with the eddy-covariance method using data from instruments on a 447-m tower in the forest of northern Wisconsin is addressed. The primary goal of this study is the validation of the methods used to determine the net ecosystem exchange of CO2. …
Journal: Journal Of Atmospheric And Oceanic Technology, Volume 18 (4): 529-542 (2001). DOI: 10.1175/1520-0426(2001)018<0529:LTCDFF>2.0.CO;2 Sites: US-PFa