Carbon dioxide exchange and growth of a pine plantation

There has been some controversy concerning the rate of deposition of particles having diameters near 1.0 pm to vegetated surfaces. In this size range, the processes of Brownian diffusion and inertial impaction are not effective and deposition to smooth surfaces reaches a minimum. However, most measurements of deposition of micrometer diameter particles to vegetated surfaces indicate a greater deposition than extrapolation of the results from less rough surfaces would suggest. In this study, the aerodynamic profile method was used to estimate deposition to a pine plantation. The deposition velocities were found to be sensitive to the displacement height and the form of the profile stability correction used in the calculations. An analysis of a limited set of Bowen ratio data, collected over the same forest, suggests that the data are reasonably described by using a displacement height of 7.9 m and the stability correction proposed by Raupach (1979).The average deposition velocities, measured over a 9-month period were 0.0043, 0.0078, and 0.0092 m/s for the three diameter classes 0.5-1.0, 1.0-2.0 and 2.0-5.0 pm. These deposition velocities are lower than the corresponding aerodynamic conductance for the same periods, indicating that the deposition rate is limited by surface phenomena. Average surface conductances calculated for the three size classes of particles were 0.0060, 0.0141, and 0.0276 m/s, respectively. A multiple regression analysis showed high correlation between deposition velocity and wind speed. No other measured environmental factor or linear combination of factors was significantly correlated with deposition velocity.

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“…In loblolly pine, the needles are retained for two summers. A further description of the site can be found in Murphy (1985).…”

Section: Expekimentai Sitementioning

confidence: 99%

Dry deposition of particles to a pine plantation

Lorenz

Murphy

1989

Boundary-Layer Meteorol

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“…In the other four studies (Wharton et al 2009, Baldocchi 1989, Baldocchi et al 2004, Blanken et al 1997, the net radiant energy less heat flux to the ground was partitioned using eddy correlation measurements of convective and latent heat. Measurement periods varied from daily averages (Baldocchi 1989, Ewers et al 2001) to hour averages (Murphy et al 1981, Murphy et al 1985, Blanken et al 1997. Aspen-hazel forest 0.0 -2.8 Blanken et al (1997) The results summarized in the Table 1 and Table 2 indicate that deposition velocities approaching or exceeding 1.0 cm/s are found in forest stand.…”

Section: Deposition Velocity In Forestsmentioning

confidence: 99%

“…Small openings, stoma, in the leaf surface allow passage of gas between the atmosphere and the interior of the leaf. The distribution of deposition velocity in a pine forest at SRS has been estimated from a model of canopy deposition velocities based on energy balance measurement taken in that stand (Murphy 1985, Equation 14).…”

Section: Calculation Of Deposition Velocity In An Srs Pine Plantationmentioning

confidence: 99%

“…In Murphy (1985) Equation 2 was developed using regression analysis of the experimentally derived deposition velocity and the simultaneous measurements of air temperature, solar radiation and vapor density deficit. During the regression analysis the values of v d were normalized by setting v dmin and v dmax slightly below and slightly above the observed values.…”

Section: Calculation Of Deposition Velocity In An Srs Pine Plantationmentioning

confidence: 99%

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Recommended Tritium Oxide Deposition Velocity For Use In Savannah River Site Safety Analyses

Lee¹,

Murphy²,

Viner³

et al. 2012

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“…Many of the studies used the Bowen ratio approach where the measured net radiation less the measured heat flux to the ground is partitioned between convective heat transfer and latent heat transfer. In study of the SRS pine forest (Murphy et al 1981, Murphy 1985, measurements of temperature and water vapor profiles were used to determine the ratio. In the other experiment in the pine forest (Ewers et al 2001), sap flow measurements were used to determine evaporation.…”

Section: Deposition Velocity In Forestsmentioning

confidence: 99%