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- Creator:
- Steiner, Allison L., Wozniak, Matthew, Kort, Eric, and DeCola, Phil
- Description:
- Airborne pollen can impact human health by causing seasonal allergies and contribute to the total amount of particulate matter in the atmosphere. Current observations of pollen are limited in both space and time, making it is difficult to accurately forecast how pollen is released into the environment. Lidar is a ground-based remote sensing technique that can identify particles in the atmosphere, and depolarized light can identify irregularly shaped particles like pollen. We deployed a ground-based lidar with depolarization at a forested site in northern Michigan during the spring tree pollination season to understand the timing and contribution of pollen to the total amount of particulate matter in the atmosphere. We identify nine pollen events at the forested site that lead to high particulate matter in the atmosphere. This dataset includes the processed lidar data using the MiniMPL raw event count , which is calibrated and normalized to calculate the normalized relative backscatter (NRB) as a function of height (Ware et al., 2016).
- Keyword:
- lidar; University of Michigan Biological Station; aerosols; depolarization
- Citation to related publication:
- Steiner, A.L., et al. Lidar-based observations of pollen above a mixed hardwood forest in the United States. Submitted.
- Discipline:
- Engineering
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- Creator:
- Minallah, Samar and Steiner, Allison L.
- Description:
- Data format: netcdf4 , Time series duration: 2016-06-01 to 2020-10-31, Temporal resolution: Daily, and Spatial resolution: The model output was regridded to a 0.05 degree rectilinear (lat/lon) grid using the conservative remapping method ("cdo remapcon" tool).
- Keyword:
- Land surface hydrology, Great Lakes, Land surface model, NOAH-MP, WRF-Hydro, and Hydrologic modeling
- Citation to related publication:
- Minallah, S. (2022). A Study on the Atmospheric, Cryospheric, and Hydrologic Processes Governing the Evolution of Regional Hydroclimates (Doctoral dissertation, University of Michigan Ann Arbor). https://dx.doi.org/10.7302/6223
- Discipline:
- Science and Engineering
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- Creator:
- Wozniak, Matthew C., Steiner, Allison L., and Solmon, Fabien
- Description:
- Pollen grains emitted from vegetation can rupture, releasing subpollen particles (SPPs) as fine atmospheric particulates. Previous laboratory research demonstrates potential for SPPs as efficient cloud condensation nuclei (CCN). We develop the first model of atmospheric pollen grain rupture, and implement the mechanism in regional climate model simulations over spring pollen season in the United States with a CCN-dependent moisture scheme. The source of SPPs (surface or in-atmosphere) depends on region and sometimes season, due to the distribution of relative humidity and rain. Simulated concentrations of SPPs are approximately 1-10 or 1-1,000 cm-3, depending on the number of SPPs produced per pollen grain (nspg). Lower nspg (103) produces a negligible effect on precipitation, but high nspg (106) in clean continental CCN background concentrations (100 CCN cm-3) shows SPPs suppress average seasonal precipitation by 32% and shift rates from heavy to light while increasing dry days. This effect is likely smaller for polluted air. pollen_rupture_precipitation_BASE_ensemble_daily.nc - data for BASE ensemble average pollen_rupture_precipitation_SPPHIGH_ensemble_daily.nc - data for SPPHIGH ensemble average pollen_rupture_precipitation_SPPLIT_ensemble_daily.nc - data for SPPLIT ensemble average
- Citation to related publication:
- Wozniak, M. C., Solmon, F., Steiner, A. L. (2018). Pollen Rupture and Its Impact on Precipitation in Clean Continental Conditions. Geophysical Research Letters, 45(14), 7156-7164. https://doi.org/10.1029/2018GL077692
- Discipline:
- Science