DOCSLIB.ORG

Characterization of Aerosols Over the Great Barrier Reef: the Influence of Transported Continental Sources

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Characterization of Aerosols Over the Great Barrier Reef: the Influence of Transported Continental Sources 1 Characterization of aerosols over the Great Barrier 2 Reef: The influence of transported continental 3 sources 4 Zhenyi Chen1, Robyn Schofield2, Peter Rayner2, Tianshu Zhang1, Cheng 5 Liu1,3,4*, Claire Vincent2, Sonya Fiddes2, Robert George Ryan2, Joel 6 Alroe5, Zoran D. Ristovski5, Ruhi S. Humphries6, Melita D. Keywood6, 7 Jason Ward6 ,Clare Paton-Walsh7 , Travis Naylor7 and Xiaowen Shu1 8 9 1Key Lab of Environmental Optics and Technology, Anhui Institute of Optics and 10 Fine Mechanics, Chinese Academy of Sciences, 230031, Hefei, China 11 2School of Earth Sciences, University of Melbourne, 3010, Melbourne, VIC, Australia 12 3School of Earth and Space Sciences, University of Science and Technology of China, 13 230026, Hefei, China 14 4Center for Excellence in Regional Atmospheric Environment, Institute of Urban 15 Environment, Chinese Academy of Sciences, Xiamen, 361021, China 16 5International Laboratory for Air Quality and Health, Queensland University of 17 Technology , QLD 4000, Australia 18 6Climate Science Centre, Oceans and Atmosphere, CSIRO, 3195, Aspendale, VIC, 19 Australia 20 7School of Chemistry, University of Wollongong, 2522, NSW, Australia 21 22 *Corresponding Author. E-mail: [email protected] 23 24 25 Abstract. The rapid environmental changes in Australia prompt a more thorough 26 investigation of the influence of transportation, local emissions, and optical–chemical 27 properties on aerosol production across the region. A month-long intensive 28 measurement campaign was conducted during spring 2016 at Mission Beach, a 29 remote coastal site west of the Great Barrier Reef (GBR) on the north-east coast of 30 Australia. One aerosol pollution episode was investigated in early October. This event 31 was governed by meteorological conditions and characterized by the increase in black 32 carbon (BC) mass concentration (averaged value of 0.35±0.20 gm-3 ). Under the 1 33 influence of the continental transportation, a new layer of nucleation-mode aerosols 34 with an initial size diameter of 20 nm was observed and aerosol number 35 concentrations reached the peak of 6733 cm-3 at a diameter of 29 nm. The averaged 36 aerosol extinction coefficient at the height of 2 km was 150 Mm-1, with a small 37 depolarized ratio (3.5–5%). Simultaneously, the boundary layer height presented a 38 fall–rise trend in the presence of these enhanced aerosol concentrations and became 39 stable in a later stage of the episode. We did not observe clear boundary layer height 40 diurnal variations from the LiDAR observations or from the Weather Research and 41 Forecasting (WRF) model outputs, except in an earlier stage of the aerosol episode for 42 the former. Although the sea breeze may have been responsible for these particles, on 43 the balance of available data, we suggest that the aerosol properties at the GBR 44 surface during this period are more likely influenced by regional transportation of 45 continental sources, including biomass-burning aerosols. 46 47 1 Introduction 48 The wide-ranging effects of aerosols on the global radiative forcing system have 49 received considerable attention over the last decade. They include the modification of 50 radiation transfers and atmospheric photochemistry, cloud microphysical processes, 51 and acidification of oceans by atmospheric sulfate or nitrate deposition (Ramanathan 52 et al., 2001; Kaufman et al., 2002; Dusek et al., 2006; Doney et al., 2007). There have 53 been a number of efforts to measure aerosols in urban, rural and remote sites around 54 the globe. However, most of these studies were conducted in the Northern 55 Hemisphere (Quinn et al., 2004; Lamarque et al., 2010; Bollasina et al., 2011; Wang 2 56 et al., 2012). In the Southern Hemisphere, such as in Australia, significant gaps 57 remain in the ability to accurately quantify aerosols at high temporal and spatial 58 resolution. Satellite sensors such as Total Ozone Mapping Spectrometer (TOMS) used 59 widely to map dust source area activity and Moderate Resolution Imaging 60 Spectroradiometer (MODIS) to identify biomass-burning plume pathways face 61 several key unresolved challenges. For example, Prospero et al. (2002) found the 62 inability of TOMS to accurately identify shallow dust plumes. Myhre et al. (2008) 63 argued that high aerosol optical depth (AOD) of biomass-burning emissions may be 64 incorrectly screened out of the satellite data. Such limitations indicate that remote 65 sensing of aerosols should be combined with surface-based observations to provide 66 accurate information on aerosol characteristics. This approach has been used in 67 large-scale field campaigns such as Mate 98 (Rosen et al., 2000), BIBLE-B 68 (Takegawa et al., 2003), SAFIRED (Milic et al., 2017), and MUMBA (Guérette et al., 69 2017；Paton-Walsh et al., 2017). Although these measurements have provided much 70 information on aerosols and trace gases in Australia, detailed vertical aerosol 71 characteristics and transportation processes in this region are not fully understood. 72 Australia’s Great Barrier Reef (GBR) is a unique location to study the aerosols and 73 their potential influence on regional climate changes. In recent years, some studies 74 have been conducted to characterize the sources, coastal nucleation, and evolution 75 processes of aerosols over the GBR (Jones et al., 2007; Qin et al., 2009; Fischer and 76 Jones, 2012; Leahy et al. 2013; Swan et al., 2016). Considering that Australia is 77 mostly affected by smoke from controlled (planned) fires in the northern part of 78 Australia (Tsutsumi et al., 1999; Russell-Smith et al., 2007; Mitchell et al., 2013) and 3 79 dust in central Australia (McGowan et al., 2008), the understanding of the impact of 80 regional transportation on aerosol production and evolution properties in GBR is 81 particularly important during the dry season when biomass burning is active in 82 Northern and Eastern Australia (Carr et al., 2005; Mallet et al., 2017) . 83 Furthermore, an interpretation of aerosol measurements needs concomitant 84 measurement of meteorological condition and boundary layer. Meteorological 85 conditions including wind speed, wind direction, temperature and Relative Humidity 86 (RH) play an important role in the physical and chemical modification of aerosols 87 suspended in the BL. Meteorology also defines the atmospheric stability and therefore 88 impacts on the atmospheric vertical mixing (O'Dowd et al., 2002, Charron et al., 89 2004). The spatial–temporal description of the marine boundary layer (MBL) is more 90 complicated because it is close to the coast (Melas et al., 1995; Bates et al., 2002; 91 Tomasi et al., 2011; Winning et al., 2017). Some scientific campaigns explored the 92 impact of the evolution of the MBL in coastal sites, and its interaction with the sea 93 breeze and solar radiation (Abbs and Physick, 1992; Donaldson et al., 2012; Ribeiro 94 et al., 2018). However, there is still lack of the simultaneous observation of MBL 95 vertical evolution and its relationship with meteorology such as wind in GBR. 96 This study investigated the time variation and climatology of aerosol loading and the 97 MBL over the Great Barrier Reef. The paper is organized as follows: Section 2 98 describes the experimental setup and briefly summarizes the retrieval method for 99 signal analysis. Section 3 includes the particle size distribution, vertical profiles of the 100 aerosol extinction coefficients, depolarization ratios, and interprets the data. We 101 compared MBL heights derived from LiDAR backscattered signals with results from 102 the WRF model. Furthermore, back-trajectory analysis, MODIS AOD distribution, 103 and World Fire Atlas hot spot detection were combined to track the origin of the air 4 104 mass arriving at our observation site and the aerosol sources. Section 4 provides 105 conclusions based on the measurement results in this experiment. 106 2 Materials and methods 107 2.1 AIRBOX and site details 108 In the austral spring of 2016 the Atmospheric Integrated Research Facility for 109 Boundaries and Oxidative eXperiment (AIRBOX) was conducted to examine aerosol 110 production and evolution from the Great Barrier Reef in more detail and to explore its 111 influence on local and global climate. A range of measurements encompassing 112 aerosols, trace gases, and meteorological parameters were made throughout the 113 campaign. The AIRBOX facility was located at Mission Beach in Queensland, 114 Australia, close to the south Coral Sea. Our observation site is a remote coastal 115 headland located on the north-east coast of Australia (17.82250 S, 146.102365 E; 116 Figure 1), far from local anthropogenic sources of particles, such as roads. The 117 intensive campaign was conducted for nearly a month, from 20 September to 16 118 October 2016. 119 2.2 Instrumentation 120 2.2.1 LiDAR 121 A Scanning Mini Micro Pulse LiDAR System (MiniMPL-532-C Micro, Sigma Space 122 Corporation, Lanham, MD, USA) was installed and operated during the campaign 123 period. The pulsed system operates at a wavelength of 532 nm, retrieves aerosol 124 backscatter every 30 m, up to 9990 m, with a temporal resolution between 10 and 30 s. 125 It has a cross-polarization detection channel, which enables the delivery of two-range 126 and sky background-corrected parallel and perpendicular signals from the 127 instrument’s software. The overlapping factor between the laser beam and the field of 5 128 view (FOV) became unity when the range from the LiDAR is 114 m. As a secondary 129 product, the software computes the total backscatter coefficient. During operation, 130 however, some gaps exist in the time series of the backscatter signals due to 131 instrumental problems. 132 We calibrated the LiDAR by using clear-air signals in the far range for each profile. 133 As multiple scattering effects can usually be neglected, accurate fields of the 134 backscatter coefficient were derived, even though some uncertainties arise from the 135 prescribed LiDAR ratio profile (Kovalev, 1995).
Load more

Recommended publications
  • Statistical Mechanics I: Exam Review 1 Solution
    8.333: Statistical Mechanics I Fall 2007 Test 1 Review Problems The first in-class test will take place on Wednesday 9/26/07 from 2:30 to 4:00 pm. There will be a recitation with test review on Friday 9/21/07. The test is ‘closed book,’ but if you wish you may bring a one-sided sheet of formulas. The test will be composed entirely from a subset of the following problems. Thus if you are familiar and comfortable with these problems, there will be no surprises! ******** You may find the following information helpful: Physical Constants 31 27 Electron mass me 9.1 10− kg Proton mass mp 1.7 10− kg ≈ × 19 ≈ × 34 1 Electron Charge e 1.6 10− C Planck’s const./2π ¯h 1.1 10− Js− ≈ × 8 1 ≈ × 8 2 4 Speed of light c 3.0 10 ms− Stefan’s const. σ 5.7 10− W m− K− ≈ × 23 1 ≈ × 23 1 Boltzmann’s const. k 1.4 10− JK− Avogadro’s number N 6.0 10 mol− B ≈ × 0 ≈ × Conversion Factors 5 2 10 4 1atm 1.0 10 Nm− 1A˚ 10− m 1eV 1.1 10 K ≡ × ≡ ≡ × Thermodynamics dE = T dS+dW¯ For a gas: dW¯ = P dV For a wire: dW¯ = Jdx − Mathematical Formulas √π ∞ n αx n! 1 0 dx x e− = αn+1 2 ! = 2 R 2 2 2 ∞ x √ 2 σ k dx exp ikx 2σ2 = 2πσ exp 2 limN ln N! = N ln N N −∞ − − − →∞ − h i h i R n n ikx ( ik) n ikx ( ik) n e− = ∞ − x ln e− = ∞ − x n=0 n! � � n=1 n! � �c P 2 4 P 3 5 cosh(x) = 1 + x + x + sinh(x) = x + x + x + 2! 4! · · · 3! 5! · · · 2πd/2 Surface area of a unit sphere in d dimensions Sd = (d/2 1)! − 1 1.
    [Show full text]
  • Interfaces in Aquatic Ecosystems: Implications for Transport and Impact of I Anthropogenic Compounds Luhbds-«6KE---C)I‘> "Rol°
    Interfaces in aquatic ecosystems: Implications for transport and impact of I anthropogenic compounds luhbDS-«6KE---c)I‘> "rol° STER DISTfiStihON OF THIS DOCUMENT iS UNUMITED % In memory of Fetter, victim of human negligence and To my family andfriends Organization Document name LUND UNIVERSITY DOCTORAL DISSERTATION Department of Ecology Date of issue November 19, 1996 Chemical Ecology and Ecotoxicology Ecology Building CODEN: SE- LUNBDS/NBKE-96/1010+136 S-223 62 Lund, Sweden Authors) Sponsoring organization Swedish Environ­ JOHANNES KNULST mental Research Institute (IVL) Title and subtitle Interfaces in aquatic ecosystems : Implications for transport and impact of anthropogenic compounds Abstract Mechanisms that govern transport, accumulation and toxicity of persistent pollutants at interfaces in aquatic ecosystems were the foci of this thesis . Specific attention was paid to humic substances, their occurrence, composition, and role in exchange processes across interfaces. It was concluded that: The composition of humic substances in aquatic surface microlavers is different from that of the subsurface water and terrestrial humic mat­ ter. Levels of dissolved organic carbon (DOC)in the aquatic surface micro ­ layer reflect the DOC levels in the subsurface water. While the levels and enrichment of DOC in the microlaver generally show small variations, the levels and enrichment of particulate organic car­ bon (POC) vary to a great extent. Similarities exist between aquatic surface films, artificial semi-per­ meable and biological membranes regarding their structure and function ­ ing. Acidification and liming of freshwater ecosystems affect DOC:POC ratio and humic composition of the surface film, thus influencing the parti­ tioning of pollutants across aquatic interfaces. 21 Properties of lake catchment areas extensively govern DOC:POC ratio both 41 in the surface film and subsurface water.
    [Show full text]
  • Laboratory: Archimedes' Principle
    Phy1401: General Physics I Laboratory Page 1 of 4 Laboratory: Archimedes' Principle Introduction: Eureka!! In this lab your goal is to perform some experiments to understand the source of Archimedes’ excitement when he discovered that the buoyant force on an object in a liquid is equal to the weight of the liquid that the object displaces. Archimedes made his discovery without the benefit of Newton's insights. He was arguably the premier scientist of antiquity. Since you have Newton's achievements as part of your intellectual heritage (Phy211) we'll use the concepts of force and equilibrium to measure the buoyant force acting on a (partially or totally) submerged object. Here is the idea behind the experiment. Suppose we hang a small mass from a force sensor, arranged in the configuration shown in the figure below. The bob in the liquid may be partially or totally submerged. H2O Force Sensor mass graduated cylinder According to Archimedes, the upward buoyant force (FB), which the liquid exerts on the object, is equal to the weight of the fluid displaced or: FB = mfluidg = (ρfluidV)g (1). It should be noted, the buoyant force produced by the displacement of fluid in the cylinder will result in a reaction force of equal but opposite magnitude exerted by the bob on the rd liquid (according to Newton’s 3 Law). We will use this action-reaction relation to measure the buoyant “reaction” force with a standard digital scale. While the mass is hanging, the force sensor will measure the tension in the string (FT1), which should be equal to the weight of the suspended mass.
    [Show full text]
  • Floating with Surface Tension from Archimedes to Keller
    FLOATING WITH SURFACE TENSION FROM ARCHIMEDES TO KELLER Dominic Vella Mathematical Institute, University of Oxford 1 GFD Newsletter 2006 Faculty of Walsh College JBK @ WHOI Joe was a regular fixture of the Geophysical Fluid Dynamics programme (run at Woods Hole since 1959 – last attended in 2015) usual magic in the Lab. We continue to be endebted to W.H.O.I. Education, who once more provided a perfect atmosphere. Jeanne Fleming, Penny Foster and Janet Fields all contributed importantly to the smooth running of the program. The 2006 GFD Photograph. GFD Photo – 2006 A Sketch of the Summer Ice was the topic under discussion at Walsh Cottage during the 2006 Geophysical Fluid Dynamics Summer Study Program. Professor Grae Worster (University of The dragon enters the ice field. Cambridge) was the principal lecturer, and navigated our path through the fluid dynamics of icy processes in GFD. Towards the end of Grae’s lectures, we also held the 2006 GFD Public Lecture. This was given by Schedule of Principal Lectures Greg Dash of the University of Washington, on matters Week 1: of ice physics and a well-known popularization: “Nine Monday, June 19: Introduction to Ice Ices, Cloud Seeding and a Brother’s Farewell; how Kurt Tuesday, June 20: Diffusion-controlled solidification Vonnegut learned the science for Cat’s Cradle (but con- Wednesday, June 21: Interfacial instability in super- veniently left some out).” We again held the talk at Red- cooled fluid field Auditorium, and relaxed in the evening sunshine Thursday, June 22: Interfacial instability in two- at the reception afterwards. As usual, the principal lec- component melts tures were followed by a variety of seminars on topics icy and otherwise.
    [Show full text]
  • Hydrostatic Pressure in Small Phospholipid Vesicles
    Proc. Natl. Acad. Sci. USA Vol. 76, No. 7, pp. 3318-3319, July 1979 Biophysics Hydrostatic pressure in small phospholipid vesicles (surface tension/phospholipid bilayer) CHARLES TANFORD Whitehead Medical Research Institute and Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710 Contributed by Charles Tanford, April 18, 1979 ABSTRACT The internal solvent-filled cavity of a single- condition that phases a and c be at the same pressure requires walled spherical phospholipid vesicle must be at essentially the (Eq. 1) that the interfacial tensions Yab and ybc be related as same pressure as the aqueous medium outside the vesicle. Whether or not the bilayer itself is under elevated pressure = - [2] cannot at present be determined. 'Yab/Ro Yh/Rii, in which R. and Ri are the external and internal radii of the It is a fundamental principle of surface chemistry (law of La- vesicle, respectively. If the surface tensions are not zero, one place) that the hydrostatic pressure on the two sides of a curved of the surface tensions must therefore be negative. Alternatively, surface between two homogeneous fluids is different (see ref. however, the entire system, including the bilayer phase b, can 1, for example). For a spherical surface of radius R, the relation be at the same pressure, with 'Yab and ybc both equal to zero. between the equilibrium pressure Pi on the concave side and Negative surface tensions cannot exist at the interface be- the pressure P2 on the convex side is given by tween two simple homogeneous fluids because the interface disappears when y = 0 and the two fluids become miscible (1).
    [Show full text]
  • Nonzero Ideal Gas Contribution to the Surface Tension of Water
    This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes. Letter pubs.acs.org/JPCL Nonzero Ideal Gas Contribution to the Surface Tension of Water † ‡ ¶ § ∥ Marcello Sega,*, Balazś Fabiá n,́ , and Paĺ Jedlovszky , † University of Vienna, Boltzmangasse 5, A-1090 Vienna, Austria ‡ Institut UTINAM (CNRSUMR6213), UniversitéBourgogne Franche Comtè16 route de Gray, F-25030 Besancon,̧ France ¶ Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szt. Gellert́ teŕ 4, H-1111 Budapest, Hungary § Department of Chemistry, Eszterhazý Karolý University, Leanyká u. 6, H-3300 Eger, Hungary ∥ MTA-BME Research Group of Technical Analytical Chemistry, Szt. Gellert́ teŕ 4, H-1111 Budapest, Hungary *S Supporting Information ABSTRACT: Surface tension, the tendency of fluid interfaces to behave elastically and minimize their surface, is routinely calculated as the difference between the lateral and normal components of the pressure or, invoking isotropy in momentum space, of the virial tensor. Here we show that the anisotropy of the kinetic energy tensor close to a liquid− vapor interface can be responsible for a large part of its surface tension (about 15% for water, independent from temperature). he surface tension of a fluid can be obtained in several In water, however, the softest internal degree of freedom, the T ways from the microscopic variables describing the bending mode, has a frequency of about 1640 cm−1. This system: the so-called mechanical route links the surface tension corresponds, at room temperature, to an activation energy for fi of a planar interface to the imbalance between the normal (pN) the rst excited state of roughly 7.8kBT and a corresponding γp ∫ ∞ −3 and lateral (pT) components of the pressure tensor, = −∞pN average energy of about 3 × 10 k T.
    [Show full text]
  • THE DAVIS MUSEUM PRESENTS TABITHA SOREN: SURFACE TENSION Your Intense Relationship with Technology Is Actually a Work of Art
    FOR IMMEDIATE RELEASE December 12, 2018 THE DAVIS MUSEUM PRESENTS TABITHA SOREN: SURFACE TENSION Your Intense Relationship with Technology is Actually a Work of Art WELLESLEY, Mass. – The Davis Museum at Wellesley College explores human engagement with digital devices in Tabitha Soren: Surface Tension, an exhibition of photography by former television journalist Tabitha Soren. The exhibition of 20 photographs from Soren’s Surface Tension series invites the viewers to look beyond the picture and see how it was consumed by its intended audience. Surface Tension, on view in the Morelle Lasky Levine '56 Works on Paper Gallery, runs from February 7 through June 9, 2019. Tabitha Soren’s Surface Tension intervenes into the cool, disembodied, transactional relationships we conduct with our digital devices—and meddles with the “neutrality” of the information we receive through them. Soren pulls images from social media, web searches, images shared by friends and family, and screengrabs from news videos. Her subjects are united by a focus on touch, reinstating the haptic as an essential aspect of our human experience, and the images carry a charge that is at once familiar and uncanny. Soren shoots iPad screens with an 8 x 10 view camera under raking light to reveal the grime we leave behind—the fingerprints and greasy smears of our embodied selves, so seemingly at odds with the chilly detachment and objectivity of the information that flows towards us, unrelentingly. The photographs are titled simply as urls, bringing viewers back to the “original” of the image while signaling both instantaneity and mediation. It not only considers “how people consume, manipulate, dismiss, cherish, interact with image-driven content online—and the relentless layering that accompanies this experience,” but insists that we pause to reconsider too.
    [Show full text]
  • SURFACE TENSION Activity Plan – Science Series Actpa023
    Natural Resources - Water WHAT’S SO SPECIAL ABOUT WATER: SURFACE TENSION Activity Plan – Science Series ACTpa023 BACKGROUND Project Skills: Water is a molecule made up of 2 parts hydrogen and 1 part oxygen. Children have • Discovery of chemical fun learning how water “sticks together.” Children become more empathetic when and physical properties they listen and share their own life experiences about why people need to stick of water. together. Surface tension is a force that holds the surface of liquids together. It ensures Life Skills: that the surface area of the liquid is minimized. So water droplets form spheres. It • Empathy – is sensitive to results from the fact that atoms on the surface are missing bonds that hold the others’ situations molecules together. Water has a strong surface tension. Science Skills: Key vocabulary words: • Making hypotheses • Surface tension is the attraction of molecules to each other on a liquid surface. • The atom is the smallest unit of matter that can take part in a chemical reaction. Academic Standard: It is the building block of matter. The activity complements • A molecule consists of two or more atoms chemically bonded together. this academic standard: • Science C. 4.2. Use the WHAT TO DO science content being Activity: Amazing Water Race and Water Stretch learned to ask questions, 1. Take the laminated “Amazing Water Race” Activity Sheet and drop water from plan investigations, the eye dropper onto the Start circle. Move the droplet through the maze using make observations, make the eye dropper to the finish line. predictions, test 2. Set up multiple laminated race tracks so more than predictions, and offer one person can do the race at the same time.
    [Show full text]
  • Oil Spills in Coral Reefs PLANNING & RESPONSE CONSIDERATIONS
    Oil Spills in Coral Reefs PLANNING & RESPONSE CONSIDERATIONS ATMOSP ND HE A RI IC C N A A D E M I C N O I S L T A R N A O T I I T O A N N U .S E . C D R E E PA M RT OM MENT OF C July 2010 U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration • National Ocean Service • Office of Response and Restoration Oil Spills in Coral Reefs: Planning and Response Considerations Second edition edited by: Ruth A. Yender,1 and Jacqueline Michel2 First edition edited by: Rebecca Z. Hoff1 Contributing Authors: Gary Shigenaka,1 Ruth A. Yender,1 Alan Mearns,1 and Cynthia L. Hunter3 1 NOAA Office of Response and Restoration, 2 Research Planning, Inc., 3 University of Hawaii July 2010 U.S. Department of Commerce National Oceanic and Atmospheric Administration National Ocean Service Office of Response and Restoration Cover photo: NOAA. Florida Keys National Marine Sanctuary . Oil Spills in Coral Reefs: Planning and Response Considerations Table of Contents Chapter 1. Coral Reef Ecology 7 Chapter 2. Global And Local Impacts To Coral Reefs 19 Chapter 3. Oil Toxicity To Corals 25 Chapter 4. Response Methods For Coral Reef Areas 37 Chapter 5. Coral Reef Restoration 51 Chapter 6. Coral Case Studies 59 Appendices Glossary 79 Coral Websites 81 Figures Figure 1.1. Coral reef types 8 Figure 1.2. Example of a fore reef community and reef zones 9 Figure 4.1. Overview of possible impacts at a vessel accident 38 Tables Table 1.1.
    [Show full text]
  • Lecture 8: Surface Tension, Internal Pressure and Energy of a Spherical Particle Or Droplet
    Lecture 8: Surface tension, internal pressure and energy of a spherical particle or droplet Today’s topics • Understand what is surface tension or surface energy, and how this balances with the internal pressure of a droplet to determine the droplet size. • Why smaller droplets are not stable and tend to fuse into larger ones? So far, we have considered only bulk quantities of any given substance when describing its thermodynamic properties. The role of surfaces/interfaces is ignored. However, when the substance shrink in size down to a small droplet, particle, or precipitate, the effects of surface/interface is no longer negligible, since the number atoms on Surface/Interface is comparable to number of atoms inside bulk. Surface effects (surface energy) play critical role many kinetics process of materials, such as the particle ripening and nucleation, as we will learn the lectures later. Typically, for many liquids and solid, surface energy (surface tension) is in the order of ~ 1 J/m2 (or N/m). For example, for water under ambient conditions, the surface energy is 0.072 J/m2 (or surface tension of 0.072 N/m). Think about a large oil droplet suspending in a cup of water: shake the cup, the oil droplet will disperse as many small ones, but these small droplets will eventually fuse together, forming back to a large one if let the cup stabilize for a while. This is because the increased surface energy due to the smaller droplets (particles), fusing back to one large particle decreases the total energy, favorable in thermodynamic. Essentially every phase transformation begins with the formation of a tiny spherical particle called nucleus.
    [Show full text]
  • Sea Spray Aerosol Organic Enrichment, Water Uptake and Surface Tension Effects
    Atmos. Chem. Phys., 20, 7955–7977, 2020 https://doi.org/10.5194/acp-20-7955-2020 © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License. Sea spray aerosol organic enrichment, water uptake and surface tension effects Luke T. Cravigan1, Marc D. Mallet1,a, Petri Vaattovaara2, Mike J. Harvey3, Cliff S. Law3,4, Robin L. Modini5,b, Lynn M. Russell5, Ed Stelcer6;, David D. Cohen6, Greg Olsen7, Karl Safi7, Timothy J. Burrell3, and Zoran Ristovski1 1School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, Australia 2Department of Environmental Science, University of Eastern Finland, Kuopio, Finland 3National Institute of Water and Atmospheric Research, Wellington, New Zealand 4Department of Marine Sciences, University of Otago, Dunedin, New Zealand 5Scripps Institute of Oceanography, University of California, San Diego, La Jolla, California, USA 6Centre for Accelerator Science, NSTLI, Australian Nuclear Science and Technology Organisation, Menai, NSW, Australia 7National Institute of Water and Atmospheric Research, Hamilton, New Zealand anow at: Australian Antarctic Program Partnership, Institute for Marine and Antarctic Science, University of Tasmania, Hobart, Australia bnow at: Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland deceased Correspondence: Zoran Ristovski ([email protected]) Received: 4 September 2019 – Discussion started: 19 September 2019 Revised: 9 May 2020 – Accepted: 27 May 2020 – Published: 9 July 2020 Abstract. The aerosol-driven radiative effects on marine concentration ratios of approximately 0.1–0.2. The enrich- low-level cloud represent a large uncertainty in climate sim- ment of organics was compared to the output from the ulations, in particular over the Southern Ocean, which is also chlorophyll-a-based sea spray aerosol parameterisation sug- an important region for sea spray aerosol production.
    [Show full text]
  • The Effect of Temperature on the Surface Tension of Sap of Thuja Plicata Heartwood
    THE EFFECT OF TEMPERATURE ON THE SURFACE TENSION OF SAP OF THUJA PLICATA HEARTWOOD A. J. Bolton and G. Koutsianitisl Department of Forestry and Wood Science, University College of North Wales, Bangor, Gwynedd, LL57 2UW, U.K. (Received 5 June 1979) ABSTRACT Capillary rise and drop volume methods were applied to the measurement of heartwood sap surface tension. Increase in sap temperature appeared to cause a substantial decrease in surface tension as measured by the former method. Since with the latter method surface tension values only decreased from 58.1 to 56.8 dyneicm over the temperature range 25 to 80 C, it was concluded that changes in the contact angle of sap on glass were likely to have affected the results obtained by the capillary rise method. The absence of a substantial decrease in sap surface tension with increasing temperature is of considerable relevance to lumber drying. Keywords: Sap, surface tension, temperature, contact angle, Thuju plicutu INTRODUCTION It is generally acknowledged that interfacial forces are partly responsible for many phenomena in timber drying. Such phenomena include the aspiration of bordered pits in coniferous species, the collapse of wood in lumber drying, the reduction of mass (liquid) flow through intercellular passageways due to the blockage of pores by gas embolisms. Stamm and Arganbright (1970) have reported measurements of sap surface tension for a number of species at ambient temper- ature. Since lumber drying is carried out at elevated temperatures, it is surprising that the literature appears to contain no reference to the effect of temperature on sap surface tension. Some relevant results were obtained in the course of a study of collapse in lumber drying (Koutsianitis 1978).
    [Show full text]