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Title: Characteristics of Water Vapor Turbulence Profiles in Convective Boundary Layers During the Wet and Dry Seasons Over Darwin

Abstract

This study explores water vapor turbulence in the convective boundary layer (CBL) using the Raman lidar observations the Atmospheric Radiation Measurement (ARM) site located at Darwin, Australia. These observations have temporal and vertical resolutions of 10 s and 37.5 m, respectively. An autocovariance technique has been used to separate out the random instrument error from the atmospheric variability during time periods when the CBL is cloud-free, quasi-stationary and well mixed. We identified 62 cases, comprising of 13 monsoon and 49 non-monsoon events, over the 5-year data record period. The seasonal variations of the vertical profiles of integral scale, variance, coefficient of the structure function, and skewness were analyzed and compared with similar observations from the Raman lidar at the ARM Southern Great Plains (SGP) site. The monsoon shows larger median variance profiles than the non-monsoon. The median profile of the variance from the non-monsoon and the SGP site are found to have similar magnitudes between 0.3-0.75 zi, while the median variance profile from the monsoon and the SGP are approximately the same between 0.9-1.1 zi. The variance and coefficient of the structure function are linearly related by height, with larger slopes in the monsoon season suggesting larger dissipation rates inmore » that season relative to the non-monsoon. The median value in the skewness is mostly positive below 0.6 zi and above this it becomes negative until it crosses zero just below 1.0 zi. Its smallest value is seen at around 0.95 zi and it remains positive above 1.0 zi.« less

Authors:
 [1];  [2];  [3];  [4]
  1. National Oceanographic and Atmospheric Administration (NOAA)
  2. NOAA
  3. Cleveland State University
  4. BATTELLE (PACIFIC NW LAB)
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1509847
Report Number(s):
PNNL-SA-125855
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Journal of Geophysical Research: Atmospheres
Additional Journal Information:
Journal Volume: 123; Journal Issue: 10
Country of Publication:
United States
Language:
English

Citation Formats

Osman, Mohammed K., Turner, D D., Heus, Thijs, and Newsom, Rob K. Characteristics of Water Vapor Turbulence Profiles in Convective Boundary Layers During the Wet and Dry Seasons Over Darwin. United States: N. p., 2018. Web. doi:10.1029/2017JD028060.
Osman, Mohammed K., Turner, D D., Heus, Thijs, & Newsom, Rob K. Characteristics of Water Vapor Turbulence Profiles in Convective Boundary Layers During the Wet and Dry Seasons Over Darwin. United States. doi:10.1029/2017JD028060.
Osman, Mohammed K., Turner, D D., Heus, Thijs, and Newsom, Rob K. Sun . "Characteristics of Water Vapor Turbulence Profiles in Convective Boundary Layers During the Wet and Dry Seasons Over Darwin". United States. doi:10.1029/2017JD028060.
@article{osti_1509847,
title = {Characteristics of Water Vapor Turbulence Profiles in Convective Boundary Layers During the Wet and Dry Seasons Over Darwin},
author = {Osman, Mohammed K. and Turner, D D. and Heus, Thijs and Newsom, Rob K.},
abstractNote = {This study explores water vapor turbulence in the convective boundary layer (CBL) using the Raman lidar observations the Atmospheric Radiation Measurement (ARM) site located at Darwin, Australia. These observations have temporal and vertical resolutions of 10 s and 37.5 m, respectively. An autocovariance technique has been used to separate out the random instrument error from the atmospheric variability during time periods when the CBL is cloud-free, quasi-stationary and well mixed. We identified 62 cases, comprising of 13 monsoon and 49 non-monsoon events, over the 5-year data record period. The seasonal variations of the vertical profiles of integral scale, variance, coefficient of the structure function, and skewness were analyzed and compared with similar observations from the Raman lidar at the ARM Southern Great Plains (SGP) site. The monsoon shows larger median variance profiles than the non-monsoon. The median profile of the variance from the non-monsoon and the SGP site are found to have similar magnitudes between 0.3-0.75 zi, while the median variance profile from the monsoon and the SGP are approximately the same between 0.9-1.1 zi. The variance and coefficient of the structure function are linearly related by height, with larger slopes in the monsoon season suggesting larger dissipation rates in that season relative to the non-monsoon. The median value in the skewness is mostly positive below 0.6 zi and above this it becomes negative until it crosses zero just below 1.0 zi. Its smallest value is seen at around 0.95 zi and it remains positive above 1.0 zi.},
doi = {10.1029/2017JD028060},
journal = {Journal of Geophysical Research: Atmospheres},
number = 10,
volume = 123,
place = {United States},
year = {2018},
month = {5}
}