Measurement of Trace Gas Fluxes over an Unfertilized Agricultural Field Using the Flux‐gradient Technique

Journal of Environmental Quality - Tập 40 Số 5 - Trang 1359-1365 - 2011
LaToya Myles1, John Kochendorfer1, Mark Heuer1, Tilden P. Meyers1
1NOAA/ARL Atmospheric Turbulence and Diffusion Division POB 2456 Oak Ridge TN 37831‐2456

Tóm tắt

Trace gas fluxes exhibit extensive spatial and temporal variability that is dependent on a number of factors, including meteorology, ambient concentration, and emission source size. Previous studies have found that agricultural fertilization contributes to higher fluxes of certain gases. The magnitude of trace gas fluxes over unfertilized crops is still uncertain. In the present study, deposition of ammonia (NH3), nitric acid (HNO3), and sulfur dioxide (SO2) was measured over unfertilized soybean using the flux‐gradient technique. The eddy diffusivity was estimated from eddy covariance measurements of temperature fluxes, resulting in KH of 0.64 ± 0.30 m2 s−1. Flux means and standard deviations were −0.14 ± 0.13, −0.22 ± 0.19, and −0.38 ± 0.54 μg m−2 s−1 for NH3, HNO3, and SO2, respectively. Low concentrations of NH3 and HNO3 increased the relative uncertainties in the deposition velocities estimated from measured fluxes. This contributed to dissimilarities between deposition velocities estimated from the resistance analogy and deposition velocities estimated from fluxes. However, wet canopy conditions during the study may have led to an underestimation of deposition by the resistance analogy because the resistance method does not accurately describe the enhanced deposition rates that occur after dew formation. Quantification of vegetation characteristics, such as leaf wetness and apoplast chemistry, would be beneficial in future studies to more accurately determine stomatal resistance and its influence on fluxes.

Từ khóa


Tài liệu tham khảo

10.1007/s11270-006-9172-4

Arya S.P., 2001, Introduction to micrometeorology, 171

10.1016/S1352-2310(97)00166-0

10.2307/1941631

10.1080/10473289.1999.10463966

10.1175/1520-0450(1986)025<1100:EOTAWW>2.0.CO;2

10.1016/j.envint.2006.05.002

10.1007/978-94-009-3841-0_52

10.1029/94JD01210

10.1016/0269-7491(92)90050-K

10.2134/jeq2007.0358

10.1016/1352-2310(94)90432-4

10.1016/1352-2310(94)90126-0

10.1641/0006-3568(2003)053[0341:TNC]2.0.CO;2

10.1016/S1352-2310(97)00201-X

10.1016/0960-1686(91)90030-B

10.1016/0004-6981(89)90062-0

10.5194/bgd-5-3965-2008

10.1007/BF00229675

Hicks B.B., 1978, An examination of some micrometeorological methods for measuring dry deposition. EPA Publ. EPA‐600/7‐78‐116

Hole L.R., 2007, Low cost measurements of nitrogen and sulphur dry deposition velocities at a semi‐alpine site: Gradient measurements and a comparison with deposition model estimates, Environ. Pollut., 154, 473, 10.1016/j.envpol.2007.06.061

10.1029/JD090iD01p02085

10.1127/0941-2948/2001/0010-0071

10.1016/S1352-2310(97)00391-9

10.1016/1352-2310(96)00082-9

10.1016/0269-7491(88)90022-X

10.1007/BF00123651

10.1016/j.agrformet.2004.10.005

10.1034/j.1600-0889.45.issue4.1.x

Myles L., 2004, A study of atmospheric ammonia in coastal ecosystems utilizing relaxed eddy accumulation techniques and ion mobility spectrometry

10.1016/j.atmosenv.2009.03.007

10.1088/1748-9326/2/3/034004

10.1016/S1352-2310(97)00162-3

10.1016/j.atmosenv.2005.05.027

10.2307/1941915

10.1111/j.1469-8137.1993.tb03882.x

10.1007/BF01186163

10.1016/j.atmosenv.2004.02.054

10.1016/S1352-2310(02)00765-3

10.1029/2006JD007843

10.1002/qj.49711951309

10.1016/S0269-7491(00)00168-8

U.S. National Acid Precipitation Assessment Program, 1990, Acidic deposition: State of science and technology—Emissions, atmospheric processes, and deposition

10.1016/j.agrformet.2006.03.011

10.1016/0004-6981(89)90153-4

10.1080/00022470.1977.10470534

10.1016/S1352-2310(99)00467-7

Winberry W.T., 1999, Compendium method for the determination of inorganic compounds in ambient air: Compendium method IO‐4.2: Determination of reactive acidic and basic gases and strong acidity of atmospheric fine particles (<2.5 um)

10.1016/j.agrformet.2008.08.012

10.1016/1352-2310(95)00233-O

10.5194/acp-3-2067-2003

Thông tin
Thông tin xuất bản

Journal of Environmental Quality

Tập 40 Số 5

1359-1365

Thông tin tác giả