Search Results

You are looking at 1 - 10 of 10 items for

  • Author or Editor: C. Flynn x
  • Refine by Access: All Content x
Clear All Modify Search
Peggy McNeal, Wendilyn Flynn, Cody Kirkpatrick, Dawn Kopacz, Daphne LaDue, and Lindsay C. Maudlin

Abstract

Educators can enrich their teaching with best practices, share resources, and contribute to the growing atmospheric science education research community by reading and participating in the scholarship of teaching and learning in atmospheric science. This body of scholarship has grown, particularly over the past fifteen years, and is now a sizable literature base that documents and exemplifies numerous teaching innovations in undergraduate atmospheric science education. This literature base benefits the entire atmospheric science community because graduates of atmospheric science programs are better prepared to enter the workforce. This literature base has not yet been examined, however, to see how well the evidence supports education practices in the atmospheric science education literature. In this study, we characterized that evidence and show that the majority of papers we reviewed share education innovations with anecdotal or correlational evidence of effectiveness. While providing useful practitioner knowledge and preliminary evidence of the effectiveness of numerous innovative teaching practices, opportunities exist for increasing readers’ confidence that the innovations caused the learning gains. Additional studies would also help move conclusions toward generalizability across academic institutions and student populations. We make recommendations for advancing atmospheric science education research and encourage atmospheric science educators to actively use the growing body of education literature as well as contribute to advancing atmospheric science education research.

Full access
Dawn Kopacz, Lindsay C. Maudlin, Wendilyn J. Flynn, Zachary J. Handlos, Adam Hirsch, and Swarndeep Gill

Abstract

Increasing participation in education research and encouraging the use of evidence-based practices in the classroom has been identified as a Grand Challenge in the Geosciences. As a first step in addressing this Grand Challenge, a survey was developed and disseminated to a broad range of atmospheric science professionals to collect data about 1) the number of community members involved in atmospheric science education research (ASER); 2) whether ASER is valued within the community, and if so, to what extent; 3) potential barriers to involvement in ASER; and 4) the resources necessary to encourage involvement in ASER. Survey results revealed that while many in the atmospheric science community highly value education research, barriers to greater involvement include a perceived lack of value and a lack of visibility of ASER. Recommendations are made for addressing these barriers.

Full access
P. W. Webley, D. Atkinson, R. L. Collins, K. Dean, J. Fochesatto, K. Sassen, C. F. Cahill, A. Prata, C. J. Flynn, and K. Mizutani
Full access
C. A. Randles, A. M. da Silva, V. Buchard, P. R. Colarco, A. Darmenov, R. Govindaraju, A. Smirnov, B. Holben, R. Ferrare, J. Hair, Y. Shinozuka, and C. J. Flynn

Abstract

The Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), updates NASA’s previous satellite-era (1980 onward) reanalysis system to include additional observations and improvements to the Goddard Earth Observing System, version 5 (GEOS-5), Earth system model. As a major step toward a full Integrated Earth Systems Analysis (IESA), in addition to meteorological observations, MERRA-2 now includes assimilation of aerosol optical depth (AOD) from various ground- and space-based remote sensing platforms. Here, in the first of a pair of studies, the MERRA-2 aerosol assimilation is documented, including a description of the prognostic model (GEOS-5 coupled to the GOCART aerosol module), aerosol emissions, and the quality control of ingested observations. Initial validation and evaluation of the analyzed AOD fields are provided using independent observations from ground, aircraft, and shipborne instruments. The positive impact of the AOD assimilation on simulated aerosols is demonstrated by comparing MERRA-2 aerosol fields to an identical control simulation that does not include AOD assimilation. After showing the AOD evaluation, this paper takes a first look at aerosol–climate interactions by examining the shortwave, clear-sky aerosol direct radiative effect. The companion paper (Part II) evaluates and validates available MERRA-2 aerosol properties not directly impacted by the AOD assimilation (e.g., aerosol vertical distribution and absorption). Importantly, while highlighting the skill of the MERRA-2 aerosol assimilation products, both studies point out caveats that must be considered when using this new reanalysis product for future studies of aerosols and their interactions with weather and climate.

Full access
S. Kondragunta, L. E. Flynn, A. Neuendorffer, A. J. Miller, C. Long, R. Nagatani, S. Zhou, T. Beck, E. Beach, R. McPeters, R. Stolarski, P. K. Bhartia, M. T. DeLand, and L.-K. Huang

Abstract

Ozone estimates from observations by the NOAA-16 Solar Backscattered Ultraviolet (SBUV/2) instrument and Television Infrared Observation Satellite (TIROS-N) Operational Vertical Sounder (TOVS) are used to describe the vertical structure of ozone in the anomalous 2002 polar vortex. The SBUV/2 total ozone maps show that the ozone hole was pushed off the Pole and split into two halves due to a split in the midstratospheric polar vortex in late September. The vortex split and the associated transport of high ozone from midlatitudes to the polar region reduced the ozone hole area from 18 × 106 km2 on 20 September to 3 × 106 km2 on 27 September 2002. A 23-yr time series of SBUV/2 daily zonal mean total ozone amounts between 70° and 80°S shows record high values [385 Dobson units (DU)] during the late-September 2002 warming event. The transport and descent of high ozone from low latitudes to high latitudes between 60 and 15 mb contributed to the unusual increase in total column ozone and a small ozone hole estimated using the standard criterion (area with total ozone < 220 DU). In contrast, TOVS observations show an ozone-depleted region between 0 and 24 km, indicating that ozone destruction was present in the elongated but unsplit vortex in the lower stratosphere. During the warming event, the low-ozone regions in the middle and upper stratosphere were not vertically aligned with the low-ozone regions in the upper troposphere and lower stratosphere. This offset in the vertical distribution of ozone resulted in higher total column ozone masking the ozone depletion in the lower stratosphere and resulting in a smaller ozone hole size estimate from satellite total ozone data.

Full access
D. D. Turner, A. M. Vogelmann, R. T. Austin, J. C. Barnard, K. Cady-Pereira, J. C. Chiu, S. A. Clough, C. Flynn, M. M. Khaiyer, J. Liljegren, K. Johnson, B. Lin, C. Long, A. Marshak, S. Y. Matrosov, S. A. McFarlane, M. Miller, Q. Min, P. Minimis, W. O'Hirok, Z. Wang, and W. Wiscombe

Many of the clouds important to the Earth's energy balance, from the Tropics to the Arctic, contain small amounts of liquid water. Longwave and shortwave radiative fluxes are very sensitive to small perturbations of the cloud liquid water path (LWP), when the LWP is small (i.e., < 100 g m−2; clouds with LWP less than this threshold will be referred to as “thin”). Thus, the radiative properties of these thin liquid water clouds must be well understood to capture them correctly in climate models. We review the importance of these thin clouds to the Earth's energy balance, and explain the difficulties in observing them. In particular, because these clouds are thin, potentially mixed phase, and often broken (i.e., have large 3D variability), it is challenging to retrieve their microphysical properties accurately. We describe a retrieval algorithm intercomparison that was conducted to evaluate the issues involved. The intercomparison used data collected at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site and included 18 different algorithms to evaluate their retrieved LWP, optical depth, and effective radii. Surprisingly, evaluation of the simplest case, a single-layer overcast stratocumulus, revealed that huge discrepancies exist among the various techniques, even among different algorithms that are in the same general classification. This suggests that, despite considerable advances that have occurred in the field, much more work must be done, and we discuss potential avenues for future research.)

Full access
E. Kassianov, M. Pekour, C. Flynn, L. K. Berg, J. Beranek, A. Zelenyuk, C. Zhao, L. R. Leung, P. L. Ma, L. Riihimaki, J. D. Fast, J. Barnard, A. G. Hallar, I. B. McCubbin, E. W. Eloranta, A. McComiskey, and P. J. Rasch

Abstract

This work is motivated by previous studies of transatlantic transport of Saharan dust and the observed quasi-static nature of coarse mode aerosol with a volume median diameter (VMD) of approximately 3.5 μm. The authors examine coarse mode contributions from transpacific transport of dust to North American aerosol properties using a dataset collected at the high-elevation Storm Peak Laboratory (SPL) and the nearby Atmospheric Radiation Measurement (ARM) Mobile Facility. Collected ground-based data are complemented by quasi-global model simulations and satellite and ground-based observations. The authors identify a major dust event associated mostly with a transpacific plume (about 65% of near-surface aerosol mass) in which the coarse mode with moderate (~3 μm) VMD is distinct and contributes substantially to total aerosol volume (up to 70%) and scattering (up to 40%). The results demonstrate that the identified plume at the SPL site has a considerable fraction of supermicron particles (VMD ~3 μm) and, thus, suggest that these particles have a fairly invariant behavior despite transpacific transport. If confirmed in additional studies, this invariant behavior may simplify considerably parameterizations for size-dependent processes associated with dust transport and removal.

Full access
Laura D. Riihimaki, Connor Flynn, Allison McComiskey, Dan Lubin, Yann Blanchard, J. Christine Chiu, Graham Feingold, Daniel R. Feldman, Jake J. Gristey, Christian Herrera, Gary Hodges, Evgueni Kassianov, Samuel E. LeBlanc, Alexander Marshak, Joseph J. Michalsky, Peter Pilewskie, Sebastian Schmidt, Ryan C. Scott, Yolanda Shea, Kurtis Thome, Richard Wagener, and Bruce Wielicki

Abstract

Industry advances have greatly reduced the cost and size of ground-based shortwave (SW) sensors for the ultraviolet, visible, and near-infrared spectral ranges that make up the solar spectrum, while simultaneously increasing their ruggedness, reliability, and calibration accuracy needed for outdoor operation. These sensors and collocated meteorological equipment are an important part of the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) User Facility, which has supported parallel integrated measurements of atmospheric and surface properties for more than two decades at fixed and mobile sites around the world. The versatile capability of these ground-based measurements includes 1) rich spectral information required for retrieving cloud and aerosol microphysical properties, such as cloud phase, cloud particle size, and aerosol size distributions, and 2) high temporal resolution needed for capturing fast evolution of cloud microphysical properties in response to rapid changes in meteorological conditions. Here we describe examples of how ARM’s spectral radiation measurements are being used to improve understanding of the complex processes governing microphysical, optical, and radiative properties of clouds and aerosol.

Full access

Indirect and Semi-direct Aerosol Campaign

The Impact of Arctic Aerosols on Clouds

Greg M. McFarquhar, Steven Ghan, Johannes Verlinde, Alexei Korolev, J. Walter Strapp, Beat Schmid, Jason M. Tomlinson, Mengistu Wolde, Sarah D. Brooks, Dan Cziczo, Manvendra K. Dubey, Jiwen Fan, Connor Flynn, Ismail Gultepe, John Hubbe, Mary K. Gilles, Alexander Laskin, Paul Lawson, W. Richard Leaitch, Peter Liu, Xiaohong Liu, Dan Lubin, Claudio Mazzoleni, Ann-Marie Macdonald, Ryan C. Moffet, Hugh Morrison, Mikhail Ovchinnikov, Matthew D. Shupe, David D. Turner, Shaocheng Xie, Alla Zelenyuk, Kenny Bae, Matt Freer, and Andrew Glen

Abstract

A comprehensive dataset of microphysical and radiative properties of aerosols and clouds in the boundary layer in the vicinity of Barrow, Alaska, was collected in April 2008 during the Indirect and Semi-Direct Aerosol Campaign (ISDAC). ISDAC's primary aim was to examine the effects of aerosols, including those generated by Asian wildfires, on clouds that contain both liquid and ice. ISDAC utilized the Atmospheric Radiation Measurement Pro- gram's permanent observational facilities at Barrow and specially deployed instruments measuring aerosol, ice fog, precipitation, and radiation. The National Research Council of Canada Convair-580 flew 27 sorties and collected data using an unprecedented 41 stateof- the-art cloud and aerosol instruments for more than 100 h on 12 different days. Aerosol compositions, including fresh and processed sea salt, biomassburning particles, organics, and sulfates mixed with organics, varied between flights. Observations in a dense arctic haze on 19 April and above, within, and below the single-layer stratocumulus on 8 and 26 April are enabling a process-oriented understanding of how aerosols affect arctic clouds. Inhomogeneities in reflectivity, a close coupling of upward and downward Doppler motion, and a nearly constant ice profile in the single-layer stratocumulus suggests that vertical mixing is responsible for its longevity observed during ISDAC. Data acquired in cirrus on flights between Barrow and Fairbanks, Alaska, are improving the understanding of the performance of cloud probes in ice. Ultimately, ISDAC data will improve the representation of cloud and aerosol processes in models covering a variety of spatial and temporal scales, and determine the extent to which surface measurements can provide retrievals of aerosols, clouds, precipitation, and radiative heating.

A supplement to this article is available online:

DOI: 10.1175/2010BAMS2935.2

Full access
David C. Leon, Jeffrey R. French, Sonia Lasher-Trapp, Alan M. Blyth, Steven J. Abel, Susan Ballard, Andrew Barrett, Lindsay J. Bennett, Keith Bower, Barbara Brooks, Phil Brown, Cristina Charlton-Perez, Thomas Choularton, Peter Clark, Chris Collier, Jonathan Crosier, Zhiqiang Cui, Seonaid Dey, David Dufton, Chloe Eagle, Michael J. Flynn, Martin Gallagher, Carol Halliwell, Kirsty Hanley, Lee Hawkness-Smith, Yahui Huang, Graeme Kelly, Malcolm Kitchen, Alexei Korolev, Humphrey Lean, Zixia Liu, John Marsham, Daniel Moser, John Nicol, Emily G. Norton, David Plummer, Jeremy Price, Hugo Ricketts, Nigel Roberts, Phil D. Rosenberg, David Simonin, Jonathan W. Taylor, Robert Warren, Paul I. Williams, and Gillian Young

Abstract

The Convective Precipitation Experiment (COPE) was a joint U.K.–U.S. field campaign held during the summer of 2013 in the southwest peninsula of England, designed to study convective clouds that produce heavy rain leading to flash floods. The clouds form along convergence lines that develop regularly as a result of the topography. Major flash floods have occurred in the past, most famously at Boscastle in 2004. It has been suggested that much of the rain was produced by warm rain processes, similar to some flash floods that have occurred in the United States. The overarching goal of COPE is to improve quantitative convective precipitation forecasting by understanding the interactions of the cloud microphysics and dynamics and thereby to improve numerical weather prediction (NWP) model skill for forecasts of flash floods. Two research aircraft, the University of Wyoming King Air and the U.K. BAe 146, obtained detailed in situ and remote sensing measurements in, around, and below storms on several days. A new fast-scanning X-band dual-polarization Doppler radar made 360° volume scans over 10 elevation angles approximately every 5 min and was augmented by two Met Office C-band radars and the Chilbolton S-band radar. Detailed aerosol measurements were made on the aircraft and on the ground. This paper i) provides an overview of the COPE field campaign and the resulting dataset, ii) presents examples of heavy convective rainfall in clouds containing ice and also in relatively shallow clouds through the warm rain process alone, and iii) explains how COPE data will be used to improve high-resolution NWP models for operational use.

Full access