htdma > Humidified Tandem Differential Mobility AnalyzerInstrument Type(s) > Baseline • Guest

The humidified tandem differential mobility analyzer (HTDMA) is part of the aerosol observing system (AOS).

It measures how aerosol particles of different initial dry sizes grow or shrink when exposed to changing relative humidity (RH). It uses two different mobility analyzers (DMA) and a humidification system to make the measurements.

One DMA selects a narrow size range of dry aerosol particles, which are exposed to varying RH conditions in the humidification system. The second (humidified) DMA scans the particle size distribution output from the humidification system.

Scanning a wide range of particle sizes enables the second DMA to measure changes in size or growth factor (growth factor = humidified size/dry size) due to water uptake by the particles. A condensation particle counter (CPC) downstream of the second DMA counts particles as a function of selected size in order to obtain the number size distribution of particles exposed to different RH conditions.

Locations

  • Fixed
  • AMF1
  • AMF2
  • AMF3

2021

Russell LM, D Lubin, I Silber, E Eloranta, J Muelmenstaedt, S Burrows, A Aiken, D Wang, M Petters, M Miller, A Ackerman, A Fridlind, M Witte, M Lebsock, D Painemal, R Chang, J Liggio, and M Wheeler. 2021. Eastern Pacific Cloud Aerosol Precipitation Experiment (EPCAPE) Science Plan. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-21-009.

Tian J, Y Zhang, S Klein, L Wang, R ├ľktem, and D Romps. 2021. "Summertime Continental Shallow Cumulus Cloud Detection Using GOES-16 Satellite and Ground-Based Stereo Cameras at the DOE ARM Southern Great Plains Site." Remote Sensing, 13(12), 10.3390/rs13122309.

Shupe M, D Chu, D Costa, C Cox, J Creamean, G de Boer, K Dethloff, R Engelmann, M Gallagher, E Hunke, W Maslowski, A McComiskey, J Osborn, O Persson, H Powers, K Pratt, D Randall, A Solomon, M Tjernstrom, D Turner, J Uin, T Uttal, J Verlinde, and D Wagner. 2021. Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Field Campaign Report. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-21-007.

McComiskey A, S Springston, and C Flynn. 2021. ARM Aerosol Measurement Science Group 2019 Strategic Planning Workshop Report. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-21-010.

Mather J. 2021. ARM User Facility 2020 Decadal Vision. Ed. by Rolanda Jundt, Robert Stafford, Stacy Larsen, U.S. Department of Energy. DOE/SC-ARM-20-014.


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