Engineering topics
Mei, Fan
Publications and source records attributed to Mei, Fan.
A Bird’s Eye View: Development of an Operational ARM Unmanned Aerial Capability for Atmospheric Research in Arctic Alaska
Here, we present that unmanned aerial capabilities offer exciting new perspectives on the Arctic atmosphere and the US Department of Energy is working with partners to offer such perspectives to the research community. Thorough understanding of aerosols, clouds, boundary layer structure and radiation is required to improve representation of the Arctic atmosphere in weather forecasting and climate models. To develop such understanding, new perspectives are needed to provide details on the vertical structure and spatial variability of key atmospheric properties, along with information over difficult-to-reach surfaces such as newly-forming sea ice. Over the last three years, the US Department of Energy (DOE) has supported various flight campaigns using unmanned aircraft systems (UAS, also known as UAVs and drones) and tethered balloon systems (TBS) at Oliktok Point, Alaska. These activities have featured in-situ measurements of thermodynamic state, turbulence, radiation, aerosol properties, cloud microphysics and turbulent fluxes to provide a detailed characterization of the lower atmosphere. Alongside a suite of active and passive ground-based sensors and radiosondes deployed by the DOE Atmospheric Radiation Measurement (ARM) program through the third ARM Mobile Facility (AMF-3), these flight activities demonstrate the ability of such platforms to provide critically-needed information. In addition to providing new and unique datasets, lessons learned during initial campaigns have assisted toward the development of an exciting new community resource.
MergedSD_Cloud_ACEENA
The merged size distribution was from three AAF instruments: FCDP, 2DS, and HVPS.
TBS Aerosol 2017
The data were collected from instruments attached on the tethered balloon system (TBS), operated at the ARM Oliktok Point site on the North Slope of Al;aska during ICARUS, 2017. The instruments include two printed optical particle spectrometers, one condensation particle counter, and an iMet sensor. The detailed information can be found in the readme file.
The observed influence of local anthropogenic pollution on northern Alaskan cloud properties
Due to their importance for the radiation budget, liquid-containing clouds are a key component of the Arctic climate system. Depending on season, they can cool or warm the near-surface air. The radiative properties of these clouds depend strongly on cloud drop sizes, which are governed in part by the availability of cloud condensation nuclei. Here, we investigate how cloud drop sizes are modified in the presence of local emissions from industrial facilities at the North Slope of Alaska. For this, we use aircraft in situ observations of clouds and aerosols from the 5th Department of Energy Atmospheric Radiation Measurement (DOE ARM) Program's Airborne Carbon Measurements (ACME-V) campaign obtained in summer 2015. Comparison of observations from an area with petroleum extraction facilities (Oliktok Point) with data from a reference area relatively free of anthropogenic sources (Utqiagvik/Barrow) represents an opportunity to quantify the impact of local industrial emissions on cloud properties. In the presence of local industrial emissions, the mean effective radii of cloud droplets are reduced from 12.2 to 9.4 µm, which leads to suppressed drizzle production and precipitation. At the same time, concentrations of refractory black carbon and condensation nuclei are enhanced below the clouds. These results demonstrate that the effects of anthropogenic pollution on local climate need to be considered when planning Arctic industrial infrastructure in a warming environment.
ARM Aerial Facility (AAF) Navigation Data
Aircraft velocity and position data from takeoff to landing. The ARM Aerial Facility (AAF) Differential Survey Module (DSM) 10Hz data is used if it is available, otherwise data from the AIMMS-20 system is used.
ARM Aerial Facility (AAF) High Volume Precipitation Spectrometer (HVPS)
ARM Aerial Facility (AAF) High Volume Precipitation Spectrometer (HVPS)
ARM Aerial Facility (AAF) 2-Dimensional Stereo Probe - Horizontal
ARM Aerial Facility (AAF) 2-Dimensional Stereo Probe - Horizontal
ARM Aerial Facility (AAF) 2-Dimensional Stereo Probe - Vertical
ARM Aerial Facility (AAF) 2-Dimensional Stereo Probe - Vertical
WCM water content for ACE-ENA
The WCM-2000, manufactured by Science Engineering Associates (SEA), is a multi-element water content measuring system that measures both liquid water content (LWC) and total water content (TWC), allowing the inference of ice water content (IWC). The TWC is measured by a scoop-shaped sensor that collects both liquid and ice phase hydrometeors. The WCM-2000 also has two heated wire elements that are exposed directly to the airstream and a reference or compensation element that is exposed to the airflow but not the condensed water. The two heated wires measure the LWC for different size droplets and are sized to match the Johnson-Williams (JW) (021 Wire) LWC probe (0.5 mm; Neel 1955) and the King (083 Wire) probe (2 mm; King et al. 1978). The WCM-2000 is calibrated according to the manufacturer instructions, which involve a dedicated test flight in cloud-free air. Each flight is also corrected for zero-offset bias using clear-air measurements
ARM Aerial Facility (AAF) - Unmanned Aircraft Systems, Fine Condensation Particle Counter via CVI Inlet, Quality Controlled
The Fine Condensation Particle Counter (or CPCF) measures sub-micron aerosol particle number concentration by condensing fluid onto particles and causing them to grow to sizes that are easily detectable by optical scattering. Counts particles with sizes that range from 10 to 3000 nanometers. Quality controlled and merged with AAF Nav data.
ARM Aerial Facility (AAF) Merged cloud size distribution
ARM Aerial Facility (AAF) Merged cloud size distribution
ARM Aerial Facility (AAF) Dew Point Temperature from Gust Probe Sensor, Corrected and Merged with Nav Data
Merges the aafdewpoint.a1 data with aafnav.b1 data to make an aafdewpoint.b1 datastream that has only data in flight. Applies standard QC, as well.