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Toward assimilation of observation-derived mixing heights to improve atmospheric tracer transport models

Kretschmer, Roberto; Koch, Frank Thomas; Feist, Dietrich G.; Biavati, Gionata; Karstens, Ute LU and Gerbig, Christoph (2012) In Geophysical Monograph Series 200. p.185-205
Abstract

Common transport models use the mixing height (MH) to determine turbulent coefficients and to obtain tracer concentrations in the planetary boundary layer (PBL). We conducted a pseudo data experiment to elucidate the impact of assimilating MHs to improve CO2 transport within the Stochastic Time-Inverted Lagrangian Transport model (STILT). Transport of CO2 was simulated for August 2006 with a receptor located at Bialystok, Poland. STILT was driven by meteorology obtained from the Weather Research and Forecasting (WRF) model, using the Yonsei University (YSU) and Mellor-Yamada-Janjic (MYJ) PBL parameterizations, which differ substantially in the produced MHs. To quantify model-data mismatch in CO2 to... (More)

Common transport models use the mixing height (MH) to determine turbulent coefficients and to obtain tracer concentrations in the planetary boundary layer (PBL). We conducted a pseudo data experiment to elucidate the impact of assimilating MHs to improve CO2 transport within the Stochastic Time-Inverted Lagrangian Transport model (STILT). Transport of CO2 was simulated for August 2006 with a receptor located at Bialystok, Poland. STILT was driven by meteorology obtained from the Weather Research and Forecasting (WRF) model, using the Yonsei University (YSU) and Mellor-Yamada-Janjic (MYJ) PBL parameterizations, which differ substantially in the produced MHs. To quantify model-data mismatch in CO2 to errors in vertical mixing, we defined the WRF-YSU simulation as known truth. Pseudo MH observations were sampled from WRF-YSU at locations of real radiosonde stations. These point observations were interpolated in space-time to the entire WRF domain using kriging with an external drift, which combines observed and modeled MHs to create a "best guess" MH field. We prescribed MHs in STILT driven by WRF-MYJ winds with the best guess to study the impact on CO 2 concentrations. Differences in CO2 between the STILT simulations were on the order of ̃0-1 and ̃1-10 ppm on average (i.e., bias), with standard deviations of ̃1-3 and ̃4-14 ppm (random error) during day (12 UTC) and nighttime (0 UTC), respectively. These were reduced when using STILT with the best guess (̃50%-80% of the bias, ̃10%-20% of the random error). Simulated CO2 concentrations and MHs were also compared to measurements made at the Bialystok tall tower. © 2012. American Geophysical Union. All Rights Reserved.

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author
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
in
Geophysical Monograph Series
volume
200
pages
21 pages
publisher
American Geophysical Union
external identifiers
  • Scopus:84899521529
DOI
10.1029/2012GM001255
language
English
LU publication?
no
id
406cd59f-6c2d-46d6-b722-45cc03a98e77
date added to LUP
2016-08-31 11:03:27
date last changed
2016-10-13 05:13:03
@misc{406cd59f-6c2d-46d6-b722-45cc03a98e77,
  abstract     = {<p>Common transport models use the mixing height (MH) to determine turbulent coefficients and to obtain tracer concentrations in the planetary boundary layer (PBL). We conducted a pseudo data experiment to elucidate the impact of assimilating MHs to improve CO<sub>2</sub> transport within the Stochastic Time-Inverted Lagrangian Transport model (STILT). Transport of CO<sub>2</sub> was simulated for August 2006 with a receptor located at Bialystok, Poland. STILT was driven by meteorology obtained from the Weather Research and Forecasting (WRF) model, using the Yonsei University (YSU) and Mellor-Yamada-Janjic (MYJ) PBL parameterizations, which differ substantially in the produced MHs. To quantify model-data mismatch in CO<sub>2</sub> to errors in vertical mixing, we defined the WRF-YSU simulation as known truth. Pseudo MH observations were sampled from WRF-YSU at locations of real radiosonde stations. These point observations were interpolated in space-time to the entire WRF domain using kriging with an external drift, which combines observed and modeled MHs to create a "best guess" MH field. We prescribed MHs in STILT driven by WRF-MYJ winds with the best guess to study the impact on CO <sub>2</sub> concentrations. Differences in CO<sub>2</sub> between the STILT simulations were on the order of ̃0-1 and ̃1-10 ppm on average (i.e., bias), with standard deviations of ̃1-3 and ̃4-14 ppm (random error) during day (12 UTC) and nighttime (0 UTC), respectively. These were reduced when using STILT with the best guess (̃50%-80% of the bias, ̃10%-20% of the random error). Simulated CO<sub>2</sub> concentrations and MHs were also compared to measurements made at the Bialystok tall tower. © 2012. American Geophysical Union. All Rights Reserved.</p>},
  author       = {Kretschmer, Roberto and Koch, Frank Thomas and Feist, Dietrich G. and Biavati, Gionata and Karstens, Ute and Gerbig, Christoph},
  language     = {eng},
  pages        = {185--205},
  publisher    = {ARRAY(0x9bd7c58)},
  series       = {Geophysical Monograph Series},
  title        = {Toward assimilation of observation-derived mixing heights to improve atmospheric tracer transport models},
  url          = {http://dx.doi.org/10.1029/2012GM001255},
  volume       = {200},
  year         = {2012},
}