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October 2017
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  1. OCT

    19

    Thursday

    Environmental & Climate Sciences Department Seminar

    11 am, Conference Room Bldg 815E

    Thursday, October 19, 2017, 11:00 am

    Hosted by: 'Steve Schwartz'

    Airborne particles are ubiquitous components of our atmosphere, originating from a variety of natural and anthropogenic sources, exhibiting a wide range of physical properties, and contributing in multiple ways to regional air quality as well as regional-to-global-scale climate. Most remain in the atmosphere for a week or less, but can traverse oceans or continents in that time, carrying nutrients or disease vectors in some cases. Bright aerosols reflect sunlight, and can cool the surface; light-absorbing particles can heat the atmosphere, suppressing cloud formation or mediating larger-scale circulations. In most cases, particles are required to collect water vapor as the initial step in cloud formation, so their presence (or absence) and their hygroscopic or hydrophilic properties can affect cloud occurrence, structure, and ability to precipitate. Grasping the scope and nature of aerosol environmental impacts requires understanding microphysical-to-global scale processes, operating on timescales from minutes to days or longer. Satellites are the primary source of observations on kilometer-to-global scales. Spacecraft observations are complemented by suborbital platforms: aircraft in situ measurements and surface-based instrument networks that operate on smaller spatial scales, some on shorter timescales. Numerical models play a third key role in this work — providing a synthesis of current physical understanding with the aggregate of measurements, and allowing for some predictive capability. This presentation will focus on what we can say about aerosol amount and type from space. Constraining particle "type" is at present the leading challenge for satellite aerosol remote sensing. We will review recent advances and future prospects, including the strengths and limitations of available approaches, and current work toward better integrating measurements with models to create a clearer picture of aerosol environmental impacts, globally.

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  1. OCT

    19

    Thursday

    Environmental & Climate Sciences Department Seminar

    "Desert Dust, Wildfire Smoke, Volcanic Ash, Urban and Industrial Pollution – Grasping the Role Particles Play in Global Climate and Regional Air Quality"

    Presented by Ralph Kahn, NASA Goddard Space Flight Center

    11 am, Conference Room Bldg 815E

    Thursday, October 19, 2017, 11:00 am

    Hosted by: 'Steve Schwartz'

    Airborne particles are ubiquitous components of our atmosphere, originating from a variety of natural and anthropogenic sources, exhibiting a wide range of physical properties, and contributing in multiple ways to regional air quality as well as regional-to-global-scale climate. Most remain in the atmosphere for a week or less, but can traverse oceans or continents in that time, carrying nutrients or disease vectors in some cases. Bright aerosols reflect sunlight, and can cool the surface; light-absorbing particles can heat the atmosphere, suppressing cloud formation or mediating larger-scale circulations. In most cases, particles are required to collect water vapor as the initial step in cloud formation, so their presence (or absence) and their hygroscopic or hydrophilic properties can affect cloud occurrence, structure, and ability to precipitate. Grasping the scope and nature of aerosol environmental impacts requires understanding microphysical-to-global scale processes, operating on timescales from minutes to days or longer. Satellites are the primary source of observations on kilometer-to-global scales. Spacecraft observations are complemented by suborbital platforms: aircraft in situ measurements and surface-based instrument networks that operate on smaller spatial scales, some on shorter timescales. Numerical models play a third key role in this work — providing a synthesis of current physical understanding with the aggregate of measurements, and allowing for some predictive capability. This presentation will focus on what we can say about aerosol amount and type from space. Constraining particle "type" is at present the leading challenge for satellite aerosol remote sensing. We will review recent advances and future prospects, including the strengths and limitations of available approaches, and current work toward better integrating measurements with models to create a clearer picture of aerosol environmental impacts, globally.

  2. NOV

    14

    Tuesday

    Environmental & Climate Sciences Department Seminar

    "To Be Announced"

    Presented by Catherine Prigent, CNRS-Institute National des Sciences de'l Univers (INSU), France

    11 am, Conference Room Bldg 815E

    Tuesday, November 14, 2017, 11:00 am

    Hosted by: '''Mike Jensen'''

    pending

  3. NOV

    20

    Monday

    Environmental & Climate Sciences Department Seminar

    "Carbonaceous Gas and Aerosol Measurements to Validate Models and Verify Emissions"

    Presented by Manvendra Dubey, Los Alamos National Laboratory

    11 am, Conference Room Bldg 815E

    Monday, November 20, 2017, 11:00 am

    Hosted by: 'Steve Schwartz'

    Earth system models rely on accurate representations of processes and emissions that are evaluated using observations. Iterative refinements are crucial for reliable and robust climate assessments, as I will illustrate with following recent case studies: Carbonaceous aerosol (CA) forcing in current models is prescribed as a balance between the warming by black carbon and the cooling by organic aerosol. However, data show that some organic aerosols called brown carbon absorb sunlight. Furthermore, transparent coatings on black carbon amplify their light absorbing potency by lensing. Such coatings could make black carbon more hydrophilic thereby reducing their lifetime and burden. I will use field and laboratory studies to uncover the fundamental chemistry controlling the optical properties and water affinity of CAs as they age to enable prognostic treatments. Atmospheric carbon dioxide (CO2) accumulation is moderated by its uptake by forests and oceans that soak up 25% each of the human emissions. How carbon sinks will respond to future climate change is uncertain. I will present observations of daily and seasonal variations of column CO2 and CO over the Amazon rainforest. I will show that both biomass burning and net ecosystem exchange that are out of phase control the seasonal CO2 cycle and are captured well by models. However, the daily CO2 drop driven by photosynthesis is biased low in models, a problem that needs to be fixed. Atmospheric Methane (CH4) that accounts for 25% of climate forcing is rising after a long hiatus. Potential causes include leaks from shale gas revolution, intensive agriculture, permafrost thaw, expand wetlands or shorter lifetime by higher Hydroxyl. I will review recent findings and focus on our discovery of the methane hot spot over Four Corners, NM attributed to fossil fuel that demonstrated reported emissions were low by a factor of 3. I will close with our development of an automated neural network methane leak detection