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- Author or Editor: Marilé Colón Robles x
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Abstract
On 21 August 2017, North America witnessed a total solar eclipse, with the path of totality passing across the United States from coast to coast. The major public interest in the event inspired the Global Learning and Observations to Benefit the Environment (GLOBE) Observer to organize a citizen science observing campaign to record the meteorological effects of the eclipse. Participants at 17 585 observing sites collected 68 620 temperature observations and 15 978 cloud observations. With 7194 sites positioned in the path of totality, participants provide a nearly unbroken record of the cloud and temperature effects of the eclipse across the contiguous United States. The collection of both temperature and cloud observations provides an opportunity to quantify the cloud–temperature relationship. The unique character of citizen science, which provides data from a large number of observations with limited quality control, requires a method that leverages the large number of observations. By grouping observing sites along the path of totality by 1° longitude bins, the errors from individual sites are averaged out and the meteorological effects of the eclipse can be determined robustly. The data reveal a distinct relationship between prevailing cloud cover and the eclipse-induced temperature depression, in which overcast conditions reduces the temperature depression by about one-half of the value from clear conditions. A comparison of the GLOBE results with mesonet data allows a test of the robustness of the citizen science results. The results also show the great benefit that research using citizen science data receives from increased numbers of participants and observations.
Abstract
On 21 August 2017, North America witnessed a total solar eclipse, with the path of totality passing across the United States from coast to coast. The major public interest in the event inspired the Global Learning and Observations to Benefit the Environment (GLOBE) Observer to organize a citizen science observing campaign to record the meteorological effects of the eclipse. Participants at 17 585 observing sites collected 68 620 temperature observations and 15 978 cloud observations. With 7194 sites positioned in the path of totality, participants provide a nearly unbroken record of the cloud and temperature effects of the eclipse across the contiguous United States. The collection of both temperature and cloud observations provides an opportunity to quantify the cloud–temperature relationship. The unique character of citizen science, which provides data from a large number of observations with limited quality control, requires a method that leverages the large number of observations. By grouping observing sites along the path of totality by 1° longitude bins, the errors from individual sites are averaged out and the meteorological effects of the eclipse can be determined robustly. The data reveal a distinct relationship between prevailing cloud cover and the eclipse-induced temperature depression, in which overcast conditions reduces the temperature depression by about one-half of the value from clear conditions. A comparison of the GLOBE results with mesonet data allows a test of the robustness of the citizen science results. The results also show the great benefit that research using citizen science data receives from increased numbers of participants and observations.
Abstract
This paper examines the effect of trade wind cumulus clouds on aerosol properties in the near-cloud environment using data from the Rain in Cumulus over the Ocean (RICO) campaign. Aerosol size distributions, particle concentrations, and optical properties are examined as a function of altitude and distance from cloud, at ambient relative humidity (RH) and adjusted to a constant RH to isolate effects of humidification from other processes.
The cloud humidity halo extended about 1500–2000 m from the cloud edge, with no clear altitude dependence on horizontal extent over an altitude range of 600–1700 m. The combined effects of vertical transport of aerosol by clouds and cloud processing contributed to the modification of aerosol size distributions within the clouds' humidity halos, particularly close to the cloud boundaries. Backscatter at 532 nm, calculated from the aerosol properties, exhibited no distinguishable trend with altitude within 400 m of cloud edges, increased toward lower altitudes beyond 400 m, and decreased away from cloud boundaries at all altitudes. The mean aerosol diameter was found to rapidly decline from 0.8 to 0.4 μm from near the cloud boundary to the boundary of the humidity halo. Aerosol optical depth at 532 nm within the layer between 600 and 1700 m increased near exponentially from 0.02 to 0.2 toward the cloud boundaries within the humidity halo. These trends agreed qualitatively with past space-based lidar measurements of trade wind cloud margins, although quantitative differences were noted that likely arose from different sampling strategies and other factors.
Abstract
This paper examines the effect of trade wind cumulus clouds on aerosol properties in the near-cloud environment using data from the Rain in Cumulus over the Ocean (RICO) campaign. Aerosol size distributions, particle concentrations, and optical properties are examined as a function of altitude and distance from cloud, at ambient relative humidity (RH) and adjusted to a constant RH to isolate effects of humidification from other processes.
The cloud humidity halo extended about 1500–2000 m from the cloud edge, with no clear altitude dependence on horizontal extent over an altitude range of 600–1700 m. The combined effects of vertical transport of aerosol by clouds and cloud processing contributed to the modification of aerosol size distributions within the clouds' humidity halos, particularly close to the cloud boundaries. Backscatter at 532 nm, calculated from the aerosol properties, exhibited no distinguishable trend with altitude within 400 m of cloud edges, increased toward lower altitudes beyond 400 m, and decreased away from cloud boundaries at all altitudes. The mean aerosol diameter was found to rapidly decline from 0.8 to 0.4 μm from near the cloud boundary to the boundary of the humidity halo. Aerosol optical depth at 532 nm within the layer between 600 and 1700 m increased near exponentially from 0.02 to 0.2 toward the cloud boundaries within the humidity halo. These trends agreed qualitatively with past space-based lidar measurements of trade wind cloud margins, although quantitative differences were noted that likely arose from different sampling strategies and other factors.
The Rain in Cumulus over the Ocean (RICO) field campaign carried out a wide array of educational activities, including a major first in a field project—a complete mission, including research flights, planned and executed entirely by students. This article describes the educational opportunities provided to the 24 graduate and 9 undergraduate students who participated in RICO.
The Rain in Cumulus over the Ocean (RICO) field campaign carried out a wide array of educational activities, including a major first in a field project—a complete mission, including research flights, planned and executed entirely by students. This article describes the educational opportunities provided to the 24 graduate and 9 undergraduate students who participated in RICO.
