An Instrument for Direct Measurement of Emissions: Cooling Tower Example

Measuring emissions from stacks is challenging due to accessibility and safety concerns, and requires techniques to address a broad range of conditions and measurement challenges. One way to facilitate such measurements is to build an instrument package and then use a crane to hold the package over the emissions source. Here we describe such an instrument package that is used to characterize both wet droplet and dried aerosol emissions from cooling tower spray drift. In this application, the instrument package characterizes the velocity, size distribution and concentration of the wet droplet emissions and the mass concentration and elemental composition of the dried PM2.5 and PM10 emissions. Subsequent papers will present and analyze the wet and dried emissions from individual towers.

Aeolian Changes at the Insight Landing Site on Mars: Multi-instrument Observations

<p>The InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) mission landed in western Elysium Planitia on November 26, 2018. Because of its stationary position and a multi-instrument package, InSight offers the unique opportunity of detecting changes induced by aeolian activity and constraining the atmospheric conditions responsible for particle motion.</p><p>In this work, we present the most significant changes from aeolian activity as detected by the InSight lander during its first 400 Martian days of operations. We will show that particle entrainment by wind activity around InSight is a subtle process and report simultaneous measurements observed across multiple instruments. The changes observed are episodic and are seen correlated with excursions in both seismic and magnetic signals, which will be discussed further. Our observations show that all aeolian movements are consistent with the passage of deep convective vortices between noon to 3 pm local time. These vortices may be the primary initiators for aeolian transportation at InSight, inducing episodic particulate motion of grains up to 3 mm in diameter.</p>

A Multipollutant Smoke Emissions Sensing and Sampling Instrument Package for Unmanned Aircraft Systems: Development and Testing

Poor air quality arising from prescribed and wildfire smoke emissions poses threats to human health and therefore must be taken into account for the planning and implementation of prescribed burns for reducing contemporary fuel loading and other management goals. To better understand how smoke properties vary as a function of fuel beds and environmental conditions, we developed and tested a compact portable instrument package that integrates direct air sampling with air quality and meteorology sensing, suitable for in situ data collection within burn units and as a payload on multi-rotor small unmanned aircraft systems (sUASs). Co-located sensors collect carbon dioxide, carbon monoxide, and particulate matter data at a sampling rate of ~0.5 Hz with a microcontroller-based system that includes independent data logging, power systems, radio telemetry, and global positioning system data. Sensor data facilitates precise remote canister collection of air samples suitable for laboratory analysis of volatile organic compounds (VOCs) and other major and trace gases. Instrument package specifications are compatible with common protocols for ground-based and airborne measurements. We present and discuss design specifications for the system and preliminary data collected in controlled burns at Tall Timbers Research Station, FL, USA and Sycan Marsh Preserve, OR, USA.