Atmos. Meas. techniques

Field assessments on impact of CO2 concentration fluctuations along with complex terrain flows on the estimation of the net ecosystem exchange of temperate forests
Dexiong Teng, Jiaojun Zhu, Tian Gao, Fengyuan Yu, Yuan Zhu, Xinhua Zhou, and Bai Yang
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2024-6,2024
Preprint under review for AMT (discussion: open, 0 comments)
Dense canopy weakens turbulent mixing, leading to significant CO2 storage (Fs), a key part of the net ecosystem exchange (NEE) using eddy covariance technique. Gust-biased Fs measurements complicates NEE estimation in forests with complex terrain. We analyzed gust-induced CO2 fluctuations and their impact on Fs. The Fs and its contribution to NEE can be explained by terrain complexity and turbulent mixing. This work highlights how gusts in complex terrains affect the Fs and NEE measurements.

Geostationary Environment Monitoring Spectrometer (GEMS) polarization characteristics and correction algorithm
Haklim Choi, Xiong Liu, Ukkyo Jeong, Heesung Chong, Jhoon Kim, Myung Hwan Ahn, Dai Ho Ko, Dong-Won Lee, Kyung-Jung Moon, and Kwang-Mog Lee
Atmos. Meas. Tech., 17, 145–164, https://doi.org/10.5194/amt-17-145-2024, 2024
GEMS is the first geostationary satellite to measure the UV--Vis region, and this paper reports the polarization characteristics of GEMS and an algorithm. We develop a polarization correction algorithm optimized for GEMS based on a look-up-table approach that simultaneously considers the polarization of incoming light and polarization sensitivity characteristics of the instrument. Pre-launch polarization error was adjusted close to zero across the spectral range after polarization correction.

Evaluation of in situ observations on Marine Weather Observer during Typhoon Sinlaku
Wenying He, Hongbin Chen, Hongyong Yu, Jun Li, Jidong Pan, Shuqing Ma, Xuefen Zhang, Rang Guo, Bingke Zhao, Xi Chen, Xiangao Xia, and Kaicun Wang
Atmos. Meas. Tech., 17, 135–144, https://doi.org/10.5194/amt-17-135-2024, 2024
The Marine Weather Observer (MWO) system completed a long-term observation, actively approaching the center of Typhoon Sinlaku on 24 July–2 August 2020, over the South China Sea. The in situ observations were evaluated through comparison with buoy observations during the evolution of Typhoon Sinlaku. As a mobile observation station, MWO has shown its unique advantages over traditional observation methods, and the results preliminarily demonstrate the reliable observation capability of MWO.

Objective identification of pressure wave events from networks of 1 Hz, high-precision sensors
Luke R. Allen, Sandra E. Yuter, Matthew A. Miller, and Laura M. Tomkins
Atmos. Meas. Tech., 17, 113–134, https://doi.org/10.5194/amt-17-113-2024, 2024
We present a data set of high-precision surface air pressure observations and a method for detecting wave signals from the time series of pressure. A wavelet-based method is used to find wave signals at specific times and wave periods. From networks of pressure sensors spaced tens of kilometers apart, the wave phase speed and direction are estimated. Examples of wave events and their meteorological context are shown using radar data, weather balloon data, and other surface weather observations.

New insights from the Jülich Ozone Sonde Intercomparison Experiment: calibration functions traceable to one ozone reference instrument
Herman G. J. Smit, Deniz Poyraz, Roeland Van Malderen, Anne M. Thompson, David W. Tarasick, Ryan M. Stauffer, Bryan J. Johnson, and Debra E. Kollonige
Atmos. Meas. Tech., 17, 73–112, https://doi.org/10.5194/amt-17-73-2024, 2024
This paper revisits fundamentals of ECC ozonesonde measurements to develop and characterize a methodology to correct for the fast and slow time responses using the JOSIE (Jülich Ozone Sonde Intercomparison Experiment) simulation chamber data. Comparing the new corrected ozonesonde profiles to an accurate ozone UV photometer (OPM) as reference allows us to evaluate the time response correction (TRC) method and to determine calibration functions traceable to one reference with 5 % uncertainty.

Quantifying particulate matter optical properties and flow rate in industrial stack plumes from the PRISMA hyperspectral imager
Gabriel Calassou, Pierre-Yves Foucher, and Jean-François Léon
Atmos. Meas. Tech., 17, 57–71, https://doi.org/10.5194/amt-17-57-2024, 2024
We propose analyzing the aerosol composition of plumes emitted by different industrial stacks using PRISMA satellite hyperspectral observations. Three industrial sites have been observed: a coal-fired power plant in South Africa, a steel plant in China, and gas flaring at an oil extraction site in Algeria. Aerosol optical thickness and particle radius are retrieved within the plumes. The mass flow rate of particulate matter is estimated in the plume using the integrated mass enhancement method.

Five years of Sentinel-5p TROPOMI operational ozone profiling and geophysical validation using ozonesonde and lidar ground-based networks
Arno Keppens, Serena Di Pede, Daan Hubert, Jean-Christopher Lambert, Pepijn Veefkind, Maarten Sneep, Johan De Haan, Mark ter Linden, Thierry Leblanc, Steven Compernolle, Tijl Verhoelst, José Granville, Oindrila Nath, Ann Mari Fjaeraa, Ian Boyd, Sander Niemeijer, Roeland Van Malderen, Herman G. J. Smit, Valentin Duflot, Sophie Godin-Beekmann, Bryan J. Johnson, Wolfgang Steinbrecht, David W. Tarasick, Debra E. Kollonige, Ryan M. Stauffer, Anne M. Thompson, Angelika Dehn, and Claus Zehner
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2023-264,2024
Preprint under review for AMT (discussion: open, 0 comments)
The Sentinel-5P satellite operated by the European Space Agency carries the TROPOspheric Monitoring Instrument (TROPOMI) around the Earth since October 2017. This mission also produces vertical ozone profile data, which is described in detail for the period May 2018 to April 2023. Independent validation using ground-based reference measurements demonstrates that the operational ozone profile product mostly fully and at least partially complies with all mission requirements.

Transferability of ML-based Global Calibration Models for NO2 and NO Low-Cost Sensors
Ayah Abu-Hani, Jia Chen, Vigneshkumar Balamurugan, Adrian Wenzel, and Alessandro Bigi
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2023-261,2024
Preprint under review for AMT (discussion: open, 0 comments)
This study examined the transferability of machine-learning calibration models among low-cost sensor units targeting NO2 and NO. The global models were evaluated under similar and different emission conditions. To counter cross-sensitivity, the study proposed integrating O3 measurements from nearby reference stations, in Switzerland. The models show substantial improvement when O3 measurements are incorporated, which is more pronounced when in regions with elevated O3 concentrations.

Validation of MUSES NH3 observations from AIRS and CrIS against aircraft measurements from DISCOVER-AQ and a surface network in the Magic Valley
Karen E. Cady-Pereira, Xuehui Guo, Rui Wang, April B. Leytem, Chase Calkins, Elizabeth Berry, Kang Sun, Markus Müller, Armin Wisthaler, Vivienne H. Payne, Mark W. Shephard, Mark A. Zondlo, and Valentin Kantchev
Atmos. Meas. Tech., 17, 15–36, https://doi.org/10.5194/amt-17-15-2024, 2024
Ammonia is a significant precursor of PM2.5 particles and thus contributes to poor air quality in many regions. Furthermore, ammonia concentrations are rising due to the increase of large-scale, intensive agricultural activities. Here we evaluate satellite measurements of ammonia against aircraft and surface network data, and show that there are differences in magnitude, but the satellite data are spatially and temporally well correlated with the in situ data.

Assessing potential indicators of aerosol wet scavenging during long-range transport
Miguel Ricardo A. Hilario, Avelino F. Arellano, Ali Behrangi, Ewan C. Crosbie, Joshua P. DiGangi, Glenn S. Diskin, Michael A. Shook, Luke D. Ziemba, and Armin Sorooshian
Atmos. Meas. Tech., 17, 37–55, https://doi.org/10.5194/amt-17-37-2024, 2024
Wet scavenging strongly influences aerosol lifetime and interactions but is a large uncertainty in global models. We present a method to identify meteorological variables relevant for estimating wet scavenging. During long-range transport over the tropical western Pacific, relative humidity and the frequency of humid conditions are better predictors of scavenging than precipitation. This method can be applied to other regions, and our findings can inform scavenging parameterizations in models.

Optimized design of flux chambers for measurement of ammonia emission after field application of slurry with full-scale farm machinery
Johanna Pedersen, Sasha D. Hafner, Andreas Pacholski, Valthor I. Karlsson, Li Rong, Rodrigo Labouriau, and Jesper N. Kamp
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2023-212,2024
Preprint under review for AMT (discussion: open, 0 comments)
Field applied animal slurry is a significant source of NH3 emission. A new system of dynamic flux chambers for NH3 measurements was developed and validated through three field trials, used to assess the variability after application with trailing hose at different scales: manual (handheld), 3-m slurry boom, and 30-m slurry boom. The measurement system facilitates NH3 emission measurement with replication after both manual and farm-scale slurry application with relatively high precision.