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Articles 1 - 18 of 18
Full-Text Articles in Physical Sciences and Mathematics
Spectral Aerosol Extinction (Spex): A New Instrument For In Situ Ambient Aerosol Extinction Measurements Across The Uv/Visible Wavelength Range, C. E. Jordan, B E. Anderson, A J. Beyersdorf, C A. Corr, Jack E. Dibb, Margaret E. Greenslade, R F. Martin, R H. Moore, Eric Scheuer, M A. Shook, Kenn L. Thornhill, D Troop, Luke D. Ziemba, E L. Winstead
Spectral Aerosol Extinction (Spex): A New Instrument For In Situ Ambient Aerosol Extinction Measurements Across The Uv/Visible Wavelength Range, C. E. Jordan, B E. Anderson, A J. Beyersdorf, C A. Corr, Jack E. Dibb, Margaret E. Greenslade, R F. Martin, R H. Moore, Eric Scheuer, M A. Shook, Kenn L. Thornhill, D Troop, Luke D. Ziemba, E L. Winstead
Earth Sciences
We introduce a new instrument for the measurement of in situ ambient aerosol extinction over the 300– 700 nm wavelength range, the spectral aerosol extinction (SpEx) instrument. This measurement capability is envisioned to complement existing in situ instrumentation, allowing for simultaneous measurement of the evolution of aerosol optical, chemical, and physical characteristics in the ambient environment. In this work, a detailed description of the instrument is provided along with characterization tests performed in the laboratory. Measured spectra of NO2 and polystyrene latex spheres (PSLs) agreed well with theoretical calculations. Good agreement was also found with simultaneous aerosol extinction measurements at …
Neither Dust Nor Black Carbon Causing Apparent Albedo Decline In Greenland's Dry Snow Zone: Implications For Modis C5 Surface Reflectance, Chris Polashenski, Jack E. Dibb, Mark G. Flanner, Justin Y. Chen, Zoe R. Courville, Alexandra M. Lai, James J. Schauer, Martin M. Shafer, Mike Bergin
Neither Dust Nor Black Carbon Causing Apparent Albedo Decline In Greenland's Dry Snow Zone: Implications For Modis C5 Surface Reflectance, Chris Polashenski, Jack E. Dibb, Mark G. Flanner, Justin Y. Chen, Zoe R. Courville, Alexandra M. Lai, James J. Schauer, Martin M. Shafer, Mike Bergin
Earth Sciences
Remote sensing observations suggest Greenland ice sheet (GrIS) albedo has declined since 2001, even in the dry snow zone. We seek to explain the apparent dry snow albedo decline. We analyze samples representing 2012–2014 snowfall across NW Greenland for black carbon and dust light-absorbing impurities (LAI) and model their impacts on snow albedo. Albedo reductions due to LAI are small, averaging 0.003, with episodic enhancements resulting in reductions of 0.01–0.02. No significant increase in black carbon or dust concentrations relative to recent decades is found. Enhanced deposition of LAI is not, therefore, causing significant dry snow albedo reduction or driving …
Observations Of Backscatter From Sand And Gravel Seafloors Between 170-250 Khz, Thomas C. Weber, Larry G. Ward
Observations Of Backscatter From Sand And Gravel Seafloors Between 170-250 Khz, Thomas C. Weber, Larry G. Ward
Center for Coastal and Ocean Mapping
Interpreting observations of frequency-dependence in backscatter from the seafloor offers many challenges, either because multiple frequencies are used for different observations that will later be merged or simply because seafloor scattering models are not well-understood above 100 kHz. Hindering the understanding of these observations is the paucity of reported, calibratedacoustic measurements above 100 kHz. This manuscript seeks to help elucidate the linkages between seafloor properties and frequency-dependent seafloor backscatter by describing observations of backscatter collected from sand, gravel, and bedrock seafloors at frequencies between 170 and 250 kHz and at a grazing angle of 45°. Overall, the frequency dependence appeared …
Initiatives In Using Crowdsourcing, Satellite Derived Bathymetry, And Other Non-Traditional Hydrographic/Bathymetric Measurements, Anthony Klemm, Shachak Pe'eri, John Nyberg
Initiatives In Using Crowdsourcing, Satellite Derived Bathymetry, And Other Non-Traditional Hydrographic/Bathymetric Measurements, Anthony Klemm, Shachak Pe'eri, John Nyberg
Center for Coastal and Ocean Mapping
No abstract provided.
Chart Adequacy: Workshop And Gebco Training, Limor Gur-Arieh, Yusoff Kamaruddin, Amon Kimeli, Anthony Klemm, Hirokazu Kurita, Shachak Pe'eri, Indra Budi Prasetyawan, Jae-Young Roh, Jaya Roperez, Nilupa Samarakoon, Jaqueline Sydenham, Maxlimer Vallee, Rochelle A. Wigley
Chart Adequacy: Workshop And Gebco Training, Limor Gur-Arieh, Yusoff Kamaruddin, Amon Kimeli, Anthony Klemm, Hirokazu Kurita, Shachak Pe'eri, Indra Budi Prasetyawan, Jae-Young Roh, Jaya Roperez, Nilupa Samarakoon, Jaqueline Sydenham, Maxlimer Vallee, Rochelle A. Wigley
Center for Coastal and Ocean Mapping
In July, 2015 the first NOAA Chart Adequacy Workshop was held in Silver Spring, Maryland, USA. Following a three-day workshop (14th to 16th July, 2015), four Nippon Foundation GEBCO students stayed at NOAA for an additional 10-day training at Office of Coast Survey’s Marine Chart Division. The key objective of the NOAA Chart Adequacy Workshop was to demonstrate techniques to evaluate the suitability of nautical chart products using chart quality information and publicly-available information. The attendees were cartographers, hydrographers and potential chart producers from hydrographic offices and government agencies around the world. The nations of the participants in the workshop …
Reconnaissance Surveying Using Satellite-Derived Bathymetry, Shachak Pe'eri, Patrick Keown, Michael Gonsalves
Reconnaissance Surveying Using Satellite-Derived Bathymetry, Shachak Pe'eri, Patrick Keown, Michael Gonsalves
Center for Coastal and Ocean Mapping
False Pass, AK, USA, is the eastern-most passage through the Aleutian Islands between the Bering Sea and the Pacific Ocean and provides a passage for small to mid-size vessels. The passage is considered an alternative route to Unimak Pass, AK for vessels from mainland Alaska and is estimated to be shorter by 160 to 240km. False Pass is closed every winter due to sea-ice cover that freezes the inlet system around OctoberNovember and melts only towards the spring (around March). As a result, the soft sediment of the seafloor contains mud and sand that may change the path of the …
Brown Carbon Aerosol In The North American Continental Troposphere: Sources, Abundance, And Radiative Forcing, J. Liu, Eric Scheuer, Jack E. Dibb, G S. Diskin, L D. Ziemba, K L. Thornhill, B E. Anderson, A Whisthaler, T Mikoviny, J J. Devi, M Bergin, A E. Perring, M Z. Markovic, J P. Schwarz, P Campuzano-Jost, D A. Day, J L. Jimenez, R J. Weber
Brown Carbon Aerosol In The North American Continental Troposphere: Sources, Abundance, And Radiative Forcing, J. Liu, Eric Scheuer, Jack E. Dibb, G S. Diskin, L D. Ziemba, K L. Thornhill, B E. Anderson, A Whisthaler, T Mikoviny, J J. Devi, M Bergin, A E. Perring, M Z. Markovic, J P. Schwarz, P Campuzano-Jost, D A. Day, J L. Jimenez, R J. Weber
Earth Sciences
Chemical components of organic aerosol (OA) selectively absorb light at short wavelengths. In this study, the prevalence, sources, and optical importance of this so called brown carbon (BrC) aerosol component are investigated throughout the North American continental tropospheric column during a summer of extensive biomass burning. Spectrophotometric absorption measurements on extracts of bulk aerosol samples collected from an aircraft over the central USA were analyzed to directly quantify BrC abundance. BrC was found to be prevalent throughout the 1 to 12 km altitude measurement range, with dramatic enhancements in biomass-burning plumes. BrC to black carbon (BC) ratios, under background tropospheric …
Modeling Impacts Of Changes In Temperature And Water Table On C Gas Fluxes In An Alaskan Peatland, Jia Deng, Changsheng Li, Steve Frolking
Modeling Impacts Of Changes In Temperature And Water Table On C Gas Fluxes In An Alaskan Peatland, Jia Deng, Changsheng Li, Steve Frolking
Earth Sciences
Northern peatlands have accumulated a large amount of organic carbon (C) in their thick peat profile. Climate change and associated variations in soil environments are expected to have significant impacts on the C balance of these ecosystems, but the magnitude is still highly uncertain. Verifying and understanding the influences of changes in environmental factors on C gas fluxes in biogeochemical models are essential for forecasting feedbacks between C gas fluxes and climate change. In this study, we applied a biogeochemical model, DeNitrification-DeComposition (DNDC), to assess impacts of air temperature (TA) and water table (WT) on C gas fluxes …
The Polarcat Model Intercomparison Project (Polmip): Overview And Evaluation With Observations, L K. Emmons, S R. Arnold, S A. Monks, V Huijnen, S Tilmes, K S. Law, J L. Thomas, J C. Raut, I Bouarar, S Turquety, Y Long, B Duncan, S Steenrod, S Strode, J Flemming, J Mao, J Langner, A M. Thompson, D Tarasick, E C. Apel, D R. Blake, Robert C. Cohen, Jack E. Dibb, Glenn Diskin, A Fried, S R. Hall, L Gregory Huey, Andrew Weinheimer, Armin Wisthaler, Tomas Mikoviny, J Nowak, Jeff Peischl, J M. Roberts, Thomas B. Ryerson, C Warneke, D Helmig
The Polarcat Model Intercomparison Project (Polmip): Overview And Evaluation With Observations, L K. Emmons, S R. Arnold, S A. Monks, V Huijnen, S Tilmes, K S. Law, J L. Thomas, J C. Raut, I Bouarar, S Turquety, Y Long, B Duncan, S Steenrod, S Strode, J Flemming, J Mao, J Langner, A M. Thompson, D Tarasick, E C. Apel, D R. Blake, Robert C. Cohen, Jack E. Dibb, Glenn Diskin, A Fried, S R. Hall, L Gregory Huey, Andrew Weinheimer, Armin Wisthaler, Tomas Mikoviny, J Nowak, Jeff Peischl, J M. Roberts, Thomas B. Ryerson, C Warneke, D Helmig
Earth Sciences
A model intercomparison activity was inspired by the large suite of observations of atmospheric composition made during the International Polar Year (2008) in the Arctic. Nine global and two regional chemical transport models participated in this intercomparison and performed simulations for 2008 using a common emissions inventory to assess the differences in model chemistry and transport schemes. This paper summarizes the models and compares their simulations of ozone and its precursors and presents an evaluation of the simulations using a variety of surface, balloon, aircraft and satellite observations. Each type of measurement has some limitations in spatial or temporal coverage …
Revealing Important Nocturnal And Day-To-Day Variations In Fire Smoke Emissions Through A Multiplatform Inversion, Pablo E. Saide, David A. Peterson, Arlindo Da Silva, Bruce Anderson, Luke D. Ziemba, Glenn Diskin, Glen Sachse, Jonathan Hair, Carolyn Butler, Marta Fenn, Jose L. Jimenez, Pedro Campuzano-Jost, Anne E. Perring, Joshua P. Schwarz, Milos Z. Markovic, Phil Russell, Jens Redemann, Yohei Shinozuka, David G. Streets, Fang Yan, Jack E. Dibb, Robert Yokelson, O Brian Toon, Edward Hyer, Gregory R. Carmichael
Revealing Important Nocturnal And Day-To-Day Variations In Fire Smoke Emissions Through A Multiplatform Inversion, Pablo E. Saide, David A. Peterson, Arlindo Da Silva, Bruce Anderson, Luke D. Ziemba, Glenn Diskin, Glen Sachse, Jonathan Hair, Carolyn Butler, Marta Fenn, Jose L. Jimenez, Pedro Campuzano-Jost, Anne E. Perring, Joshua P. Schwarz, Milos Z. Markovic, Phil Russell, Jens Redemann, Yohei Shinozuka, David G. Streets, Fang Yan, Jack E. Dibb, Robert Yokelson, O Brian Toon, Edward Hyer, Gregory R. Carmichael
Earth Sciences
We couple airborne, ground-based, and satellite observations; conduct regional simulations; and develop and apply an inversion technique to constrain hourly smoke emissions from the Rim Fire, the third largest observed in California, USA. Emissions constrained with multiplatform data show notable nocturnal enhancements (sometimes over a factor of 20), correlate better with daily burned area data, and are a factor of 2-4 higher than a priori estimates, highlighting the need for improved characterization of diurnal profiles and day-to-day variability when modeling extreme fires. Constraining only with satellite data results in smaller enhancements mainly due to missing retrievals near the emissions source, …
Evolution Of Brown Carbon In Wildfire Plumes, Haviland Forrister, Jiumeng Liu, Jack E. Dibb, Eric Scheuer, Luke D. Ziemba, Kenn L. Thornhill, Bruce Anderson, Glenn Diskin, Anne E. Perring, Joshua P. Schwarz, Pedro Campuzano-Jost, Douglas A. Day, Brett B. Palm, Jose L. Jimenez, Athanasios Nenes, Rodney J. Weber
Evolution Of Brown Carbon In Wildfire Plumes, Haviland Forrister, Jiumeng Liu, Jack E. Dibb, Eric Scheuer, Luke D. Ziemba, Kenn L. Thornhill, Bruce Anderson, Glenn Diskin, Anne E. Perring, Joshua P. Schwarz, Pedro Campuzano-Jost, Douglas A. Day, Brett B. Palm, Jose L. Jimenez, Athanasios Nenes, Rodney J. Weber
Earth Sciences
Particulate brown carbon (BrC) in the atmosphere absorbs light at subvisible wavelengths and has poorly constrained but potentially large climate forcing impacts. BrC from biomass burning has virtually unknown lifecycle and atmospheric stability. Here, BrC emitted from intense wildfires was measured in plumes transported over 2 days from two main fires, during the 2013 NASA SEAC4RS mission. Concurrent measurements of organic aerosol (OA) and black carbon (BC) mass concentration, BC coating thickness, absorption Ångström exponent, and OA oxidation state reveal that the initial BrC emitted from the fires was largely unstable. Using back trajectories to estimate the transport time indicates …
Nautical Chart Adequacy Evaluation Using Publicly-Available Data, Anthony Klemm, Shachak Pe'eri, Ricardo Freire, John Nyberg, Shep M. Smith Lt
Nautical Chart Adequacy Evaluation Using Publicly-Available Data, Anthony Klemm, Shachak Pe'eri, Ricardo Freire, John Nyberg, Shep M. Smith Lt
Center for Coastal and Ocean Mapping
The International Hydrographic Office (IHO) C-55 publication communicates the need to improve the collection, quality and availability of hydrographic data world-wide, while also monitoring and rectifying possible deficiencies and shortcomings that are presented on the chart. This task of evaluating the adequacy of nautical chart products poses a challenge to many national hydrographic offices. This stems from the dearth of readily available spatial information: namely, the lack of reliable and accessible vessel traffic data, and little means to assess the changing nature of both near-shore bathymetry and shoreline in a simple and reliable manner. In this paper, we present the …
Reconnaissance Surveying Of Bechevin Bay, Ak Using Satellite-Derived Bathymetry, Shachak Pe'eri, Patrick Keown, Leland P. Snyder, Michael Gonsalves, John Nyberg
Reconnaissance Surveying Of Bechevin Bay, Ak Using Satellite-Derived Bathymetry, Shachak Pe'eri, Patrick Keown, Leland P. Snyder, Michael Gonsalves, John Nyberg
Center for Coastal and Ocean Mapping
Recently, a remote sensing study has been conducted over Bechevin Bay Channel, Alaska as part of a collaboration project between NOAA and the U.S. Coast Guard (USCG). The goal of the study to develop a procedure to prioritize survey areas and plan the annual deployment of Aids to Navigation (AtoN) along the channel. Bechevin Bay is considered a priority for marine surveying because it constitutes the easternmost passage through the Aleutians from the Bering Sea to the Gulf of Alaska. The channel is located in a mud flat area, where every winter the passage is closed due to ice cover. …
Multibeam Mapping Of Feature Rich Seafloor In The U.S. Pacific Remote Islands Marine National Monument And On Mendocino Ridge Off The California Coast, Andy Armstrong, James V. Gardner, Brian R. Calder, Giuseppe Masetti
Multibeam Mapping Of Feature Rich Seafloor In The U.S. Pacific Remote Islands Marine National Monument And On Mendocino Ridge Off The California Coast, Andy Armstrong, James V. Gardner, Brian R. Calder, Giuseppe Masetti
Center for Coastal and Ocean Mapping
No abstract provided.
S-100 Overlays: A Brave New World?, Lee Alexander, C. Mcleay
S-100 Overlays: A Brave New World?, Lee Alexander, C. Mcleay
Center for Coastal and Ocean Mapping
Marine Information Overlay (MIO) is a generic term used to describe chart and navigation related information that supplement the content that is already contained in an ENC. This includes both static and dynamic information such as tide/water level, current flow, meteorological, oceanographic, and environmental protection. With the advent of S-100 and S-101, there is increased interest in providing a wide variety of ‘new’ overlay information. This paper provides a brief history of S-57 MIOs. Examples of navigational and non-navigation MIOs are given in terms of how currently used, by who, and for what purpose. Recommendations are provided for making a …
Simulating Ice Core 10be On The Glacial–Interglacial Timescale, C Elsasser, D Wagenbach, I Levin, A Stanzick, Mark J. Christl, A Wallner, S Kipfstuhl, I K. Seietstad, H Wershofen, Jack E. Dibb
Simulating Ice Core 10be On The Glacial–Interglacial Timescale, C Elsasser, D Wagenbach, I Levin, A Stanzick, Mark J. Christl, A Wallner, S Kipfstuhl, I K. Seietstad, H Wershofen, Jack E. Dibb
Earth Sciences
10Be ice core measurements are an important tool for paleoclimate research, e.g., allowing for the reconstruction of past solar activity or changes in the geomagnetic dipole field. However, especially on multi-millennial timescales, the share of production and climate-induced variations of respective 10Be ice core records is still up for debate. Here we present the first quantitative climatological model of the 10Be ice concentration up to the glacial–interglacial timescale. The model approach is composed of (i) a coarse resolution global atmospheric transport model and (ii) a local 10Be air–firn transfer model. Extensive global-scale observational data of short-lived …
Euclidean Reconstruction Of Natural Underwater Scenes Using Optic Imagery Sequence, Han Hu
Euclidean Reconstruction Of Natural Underwater Scenes Using Optic Imagery Sequence, Han Hu
Center for Coastal and Ocean Mapping
The development of maritime applications require monitoring, studying and preserving of detailed and close observation on the underwater seafloor and objects. Stereo vision offers advanced technologies to build 3D models from 2D still overlapping images in a relatively inexpensive way. However, while image stereo matching is a necessary step in 3D reconstruction procedure, even the most robust dense matching techniques are not guaranteed to work for underwater images due to the challenging aquatic environment. In this thesis, in addition to a detailed introduction and research on the key components of building 3D models from optic images, a robust modified quasi-dense …
Arctic Ocean Bathymetry: A Necessary Geospatial Framework, Martin Jakobsson, Larry A. Mayer, Dave Monahan
Arctic Ocean Bathymetry: A Necessary Geospatial Framework, Martin Jakobsson, Larry A. Mayer, Dave Monahan
Center for Coastal and Ocean Mapping
Most ocean science relies on a geospatial infrastructure that is built from bathymetry data collected from ships underway, archived, and converted into maps and digital grids. Bathymetry, the depth of the seafloor, besides having vital importance to geology and navigation, is a fundamental element in studies of deep water circulation, tides, tsunami forecasting, upwelling, fishing resources, wave action, sediment transport, environmental change, and slope stability, as well as in site selection for platforms, cables, and pipelines, waste disposal, and mineral extraction. Recent developments in multibeam sonar mapping have so dramatically increased the resolution with which the seafloor can be portrayed …