Atmospheric Radiation Measurement Climate Research Facility US Department of Energy

Tracking Aerosol Convection Interactions Experiment (TRACER)

1 October 2021 - 30 September 2022

Lead Scientist: Michael Jensen

Observatory: amf, hou

During the TRacking Aerosol Convection interactions ExpeRiment (TRACER), scientists will use the first ARM Mobile Facility (AMF1), the second-generation C-Band Scanning ARM Precipitation Radar (CSAPR2), and a small satellite (ancillary) site with radiosonde and aerosol measurements to learn more about cloud and aerosol interactions in the deep convection over the Houston, Texas, area.

The Houston region offers a unique environment where isolated convective systems are common and experience a spectrum of polluted aerosol conditions from urban and industrial areas. In addition, surrounding areas also show significantly lower background aerosol concentrations.

The TRACER campaign has been postponed from its originally planned dates due to COVID-19 risks associated with the earlier dates. The revised dates for TRACER are October 1, 2021, to September 30, 2022.

TRACER also will include a four-month intensive operational period (IOP). A climatological analysis of radar observations from the Houston/Galveston-area NEXRAD (KHGX) shows that convective initiation occurs in this area on 40 to 55 percent of the days each month of the year. The total number of convective events is strongly peaked during the months of June through September. To capture these events, the TRACER IOP will run from June 1 to September 30, 2022.

With this single IOP during the convective season of 2022, this effectively postpones the original TRACER IOP by one year.

The TRACER campaign consists of three primary sites operated by ARM:

  • the AMF1 main site (M1) in La Porte, Texas, an area that experiences significant polluted conditions
  • the ancillary site (S3) to the southwest of downtown Houston in a rural region with less pollution
  • the CSAPR2 site (S2) located approximately midway between the AMF1 and ancillary sites.

The main and CSAPR2 sites will operate during the entire TRACER campaign, while the ancillary site will only operate during the IOP. Operation dates for the three primary sites are as follows:

  • Main (M1): October 1, 2021, to September 30, 2022
  • CSAPR2 (S2): October 1, 2021, to September 30, 2022
  • Ancillary (S3): June 1 to September 30, 2022.

During the IOP, ARM will host many guest experiments and interagency collaborations at the TRACER sites. All three primary sites will host guest experiments, but most will be at the main site.

In addition, during the 2022 IOP, ARM is planning tethered balloon system (TBS) flights at the ancillary site and a secondary site at Smith Point, Texas, on the eastern shore of Galveston Bay that will be strongly influenced by the bay breeze circulation.


Sarah Brooks Pavlos Kollias Rebecca Sheesley
Don Collins Chongai Kuang Jeffrey Snyder
Scott Collis Matthew Kumjian Philip Stier
Eric Defer Toshihisa Matsui Sascha Usenko
Jiwen Fan Greg McFarquhar Sue van den Heever
James Flynn Chris Nowotarski Marcus van Lier-Walqui
Ann Fridlind Richard Orville Adam Varble
Scott Giangrande Mariko Oue Yuxuan Wang
Robert Griffin Anita Rapp Guang Zhang
Jiaxi Hu Daniel Rosenfeld Renyi Zhang
Robert Jackson Alexander Ryzhkov


  • Child Campaign


Theisen A, Y Feng, A Matthews, K Johnson, E Schuman, A Lindenmaier, T Wendler, V Castro, S Giangrande, S Collis, D Zhang, J Mather, and J Comstock. 2022. ARM FY2023 Radar Plan. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-TR-282. 10.2172/1888480.

Giangrande S, J Comstock, S Collis, J Shilling, K Gaustad, K Kehoe, S Xie, and D Zhang. 2022. Translator Plan: A Coordinated Vision for Fiscal Years 2023-2025. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-22-003. 10.2172/1893730.

Oue M, S Saleeby, P Marinescu, P Kollias, and S van den Heever. 2022. "Optimizing radar scan strategies for tracking isolated deep convection using observing system simulation experiments." Atmospheric Measurement Techniques, 15(16), 10.5194/amt-15-4931-2022.
Research Highlight

Wang D, M Jensen, D Taylor, G Kowalski, M Hogan, B Wittemann, A Rakotoarivony, S Giangrande, and J Park. 2022. "Linking synoptic patterns to cloud properties and local circulations over southeastern Texas." Journal of Geophysical Research: Atmospheres, 127(5), e2021JD035920, 10.1029/2021JD035920.
Research Highlight

Jensen MP, JH Flynn, LM Judd, P Kollias, C Kuang, G McFarquhar, R Nadkarni, H Powers, and J Sullivan. 2022. "A Succession of Cloud, Precipitation, Aerosol and Air Quality Field Experiments in the Coastal Urban Environment." Bulletin of the American Meteorological Society, 103(2), 10.1175/BAMS-D-21-0104.1.

Dorsey K, C Ireland, R Jundt, B Mundy, and R Stafford. 2022. 2021 Annual Report. Ed. by Robert Stafford, ARM User Facility. doe-sc-arm-21-023. 10.2172/1843842.

Bi C and G Isaacman-VanWertz. 2022. "Estimated timescales for wet deposition of organic compounds as a function of Henry's law constants." Environmental Science: Atmospheres, , 10.1039/D2EA00091A.


Verde R. 2021. Regimento e Estatuto da Revista Verde. Ed. by Programa Escola Verde, Programa Escola Verde. 10.2172/1833860.

Theisen A, A Lindenmaier, J Mather, J Comstock, S Collis, and S Giangrande. 2021. ARM FY2021 Radar Plan. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-TR-269. 10.2172/1777148.

Fridlind A, C Chiu, S Collis, J Comstock, S Giangrande, N Hickmon, M Jensen, M Kumjian, P Muradyan, R Newsom, A Sockol, M Sturm, and A Theisen. 2021. ARM Cloud and Precipitation Measurements and Science Group (CPMSG) Workshop Report. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-21-005.

View All Related Publications

Campaign Data Sets

IOP Participant Data Source Name Final Data
Michael Young Soil Moisture Sensor and Meteorological Station Order Data

HOU Data Sources

Name Full Name Browse Data
ACSM Aerosol Chemical Speciation Monitor Browse Data
ACSMCDCE ACSM, corrected for composition-dependent collection efficiency Browse Data
AERI Atmospheric Emitted Radiance Interferometer Browse Data
AETH Aethalometer Browse Data
AOP Aerosol Optical Properties Browse Data
AOS Aerosol Observing System Browse Data
AOSMET Meteorological Measurements associated with the Aerosol Observing System Browse Data
AOSSP2BC Aerosol Observing System Single Particle Soot Photometer Black Carbon Browse Data
APS Aerodynamic Particle Sizer Browse Data
CAMSITE camera that monitors a site area Browse Data
CCN Cloud Condensation Nuclei Particle Counter Browse Data
CEIL Ceilometer Browse Data
CEILPBLHT Boundary-layer height data with CEIL Browse Data
CO-ANALYZER Carbon Monoxide Analyzer Browse Data
CPC Condensation Particle Counter Browse Data
CPC-AIR Condensation particle counter aboard aircraft Browse Data
CSAPR C-Band Scanning ARM Precipitation Radar Browse Data
CSPHOT Sunphotometer Browse Data
DL Doppler Lidar Browse Data
DLPROF-WIND Doppler Lidar Horizontal Wind Profiles Browse Data
DLPROF-WSTATS Doppler Lidar Wind Statistics Profiles Browse Data
ECMWFDIAG European Centre for Medium Range Weather Forecasts Diagnostic Analyses Browse Data
ECOR Eddy Correlation Flux Measurement System Browse Data
GENSTATE Generator State Browse Data
GNDRAD Ground Radiometers on Stand for Upwelling Radiation Browse Data
HTDMA Humidified Tandem Differential Mobility Analyzer Browse Data
INTERPSONDE Interpolated Sonde Browse Data
IRT Infrared Thermometer Browse Data
KASACR Ka-Band Scanning ARM Cloud Radar Browse Data
KAZR Ka ARM Zenith Radar Browse Data
KAZRARSCL Active Remote Sensing of CLouds (ARSCL) product using Ka-band ARM Zenith Radars Browse Data
KAZRCFRCOR Ka-Band ARM Zenith RADAR (KAZR) CF-Radial, Corrected VAP Browse Data
LDIS Laser Disdrometer Browse Data
LDQUANTS Laser Disdrometer Quantities Browse Data
MAWS Automatic Weather Station Browse Data
MET Surface Meteorological Instrumentation Browse Data
MFR Multifilter Radiometer Browse Data
MFRSR Multifilter Rotating Shadowband Radiometer Browse Data
MPL Micropulse Lidar Browse Data
MPLCMASK Cloud mask from Micropulse Lidar Browse Data
MWR Microwave Radiometer Browse Data
MWR3C Microwave Radiometer, 3 Channel Browse Data
MWRHF Microwave Radiometer - High Frequency Browse Data
NEPHELOMETER Nephelometer Browse Data
NFOV Narrow Field of View Zenith Radiometer Browse Data
OPC Optical Particle Counter Browse Data
OZONE Ozone Monitor Browse Data
PBLHT Planetary Boundary Layer Height Browse Data
PSAP Particle Soot Absorption Photometer Browse Data
RWP Radar Wind Profiler Browse Data
SASHE Shortwave Array Spectroradiometer-Hemispheric Browse Data
SASZE Shortwave Array Spectroradiometer-Zenith Browse Data
SEBS Surface Energy Balance System Browse Data
SFCMETRADAQ-TCEQ Meteorology, radiation, and air quality data from TCEQ air quality stations Browse Data
SKYRAD Sky Radiometers on Stand for Downwelling Radiation Browse Data
SMPS Scanning mobility particle sizer Browse Data
SO2 Sulfur Dioxide Monitor Browse Data
SONDE Balloon-Borne Sounding System Browse Data
SONDEGRID Gridded Sonde VAP Product Browse Data
SONDEPARAM convective parameters derived from radiosonde data Browse Data
STEREOCAM Stereo Cameras for Clouds Browse Data
TBS Tethered Balloon System Browse Data
TSI Total Sky Imager Browse Data
UHSAS Ultra-High Sensitivity Aerosol Spectrometer Browse Data
VDIS Video Disdrometer Browse Data
VDISQUANTS Video Disdrometer VAP Browse Data
VISST Minnis Cloud Products Using Visst Algorithm Browse Data
WB Weighing Bucket Precipitation Gauge Browse Data
XSACR X-Band Scanning ARM Cloud Radar Browse Data