DOI: 10.5194/hess-23-1179-2019
论文题名: Dew frequency across the US from a network of in situ radiometers
作者: Ritter F. ; Berkelhammer M. ; Beysens D.
刊名: Hydrology and Earth System Sciences
ISSN: 1027-5606
出版年: 2019
卷: 23, 期: 2 起始页码: 1179
结束页码: 1197
语种: 英语
Scopus关键词: Atmospheric temperature
; Budget control
; Estimation
; Forestry
; Heat flux
; Radiative Cooling
; Radiometers
; Radiometry
; Sensitivity analysis
; Surface properties
; Uncertainty analysis
; Wind
; High temporal resolution
; Meteorological measurements
; Monin-Obukhov similarity theory
; Quantitative measurement
; Radiometric surface temperatures
; Statistical modeling
; Surface characteristics
; Surface temperatures
; Ecosystems
; Bowen ratio
; cooling
; dew
; ecosystem dynamics
; ecosystem health
; forest ecosystem
; frequency analysis
; grassland
; in situ measurement
; meteorology
; network analysis
; quantitative analysis
; radiometer
; relative humidity
; surface temperature
; uncertainty analysis
; United States
英文摘要: Dew formation is a ubiquitous process, but its importance to energy budgets or ecosystem health is difficult to constrain. This uncertainty arises largely because of a lack of continuous quantitative measurements on dew across ecosystems with varying climate states and surface characteristics. This study analyzes dew frequency from the National Ecological Observatory Network (NEON), which includes 11 grasslands and 19 forest sites from 2015 to 2017. Dew formation is determined at 30 min intervals using in situ radiometric surface temperatures from multiple heights within the canopy along with meteorological measurements. Dew frequency in the grasslands ranges from 15 % to 95 % of the nights with a strong linear dependency on the nighttime relative humidity (RH), while dew frequency in the forests is less frequent and more homogeneous (25±14 % , 1 standard deviation - SD). Dew mostly forms at the top of the canopy for the grasslands due to more effective radiative cooling and within the canopy for the forests because of higher within the canopy RH. The high temporal resolution of our data showed that dew duration reaches maximum values (ĝ1/46 -15 h) for RHĝ1/496 % and for a wind speed of ĝ1/4 0.5 m s - 1 0.14 ± 0.12 mm night - 1 ĝ1/4 10 W m - 2 ĝ1/43 . The radiometers used here provide canopy-averaged surface temperatures, which may underestimate dew frequency because of localized cold points in the canopy that fall below the dew point. A statistical model is used to test this effect and shows that dew frequency can increase by an additional ĝ1/45 % for both ecosystems by considering a reasonable distribution around the mean canopy temperature. The mean dew duration is almost unaffected by this sensitivity analysis. In situ radiometric surface temperatures provide a continuous, non-invasive and robust tool for studying dew frequency and duration on a fine temporal scale. © Author(s) 2019. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/163032
Appears in Collections: 气候变化与战略
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作者单位: Ritter, F., Department of Earth and Environmental Sciences, University of Illinois at Chicago, Illinois, United States; Berkelhammer, M., Department of Earth and Environmental Sciences, University of Illinois at Chicago, Illinois, United States; Beysens, D., Physique et Mécanique des Milieux Hétérogènes, CNRS, ESPCI, PSL Research University, Sorbonne Université, Sorbonne Paris Cité, Paris, France, OPUR, Paris, France
Recommended Citation:
Ritter F.,Berkelhammer M.,Beysens D.. Dew frequency across the US from a network of in situ radiometers[J]. Hydrology and Earth System Sciences,2019-01-01,23(2)