DOCSLIB.ORG

Lecture Ice in the Ocean Ice Ages and Sea Level History

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Outline for this week ESCI 1006 & 1106 Oceanography -Sea ice - Arctic and Antarctic sea ice Week 9: Lecture - Glaciers, ice streams, and icebergs - Ice cores as paleoclimatic archives Ice in the ocean - Past climate Ice ages and sea level history - Sea-level history Parts of Chapters: 4 (p. 116-117), 5 (p. 147- 148), 6 (p. 176-177), 12 (p. 337-338; p. 352) Types of Ice Sea ice formation Glacial ice - forms from the accumulation & compression When seawater begins to freeze at ~ –1.8o C, small needle-like ice of snow (land ice; source of icebergs) crystals (~3-4 mm in diameter) called frazil form. Frazil crystals consist of nearly pure fresh water. https://www.cbc.ca/news/canada/newfoundland‐labrador Sea ice - forms from the freezing of sea water and is Don Perovich floating on the surface of the ocean. Sea ice covers ~7% In calm seas, the crystals form grease ice. Thin sheets of grease of the ocean but only 0.1% of Earth’s ice volume) ice, or nilas, have smooth and an oily or greasy appearance. Sea ice formation Pressure ridge from colliding ice In rough seas, ice crystals converge into slushy pancakes. Don Perovich Pancake ice Individual pieces pile up to form rafts and solidify. Any relatively flat piece of ice >20 m is called NOAA https://www.swisseduc.ch/glaciers/antarctic floe. Ice floes then freeze Sea ice that is not more than one winter old is known as first-year ice. together into ice fields. Sea ice that lasts one or more summers is known as multiyear ice. 1 Polynya is a semipermanent area of open When sea ice forms salt is expelled into the water (brine), raising the salinity of the near-surface water. water in sea ice - Sensible-Heat (Open-Ocean) Polynyas - Latent-Heat (Coastal) Polynyas https://www.express.co.uk NASA Thomas et al. 2008. Frozen oceans in polar regions. YouTube: Time-Lapse Camera : Underwater Icicle "Finger of Death" Sea ice research: Ice breakers, submarines, satellites The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) RV Polarstern returns to the port city Bremerhaven, Oct 2020. BBC. SCICEX: Youtube Satellites measure sea ice concentration on a 25 km x Sea ice coverage 25 km grid. Sea ice concentration is the percentage of each pixel that is covered by ice. NASA Here no information about thickness (Cryosphere Today) 2 Arctic sea ice seasonality Winter Summer 2007 – NW passage (Sverdrup, 2006) Minimum Arctic sea ice and the NW Passage (NY Times The Big Melt videos x 2) Antarctic sea ice seasonality Arctic vs. Antarctic sea ice seasonality Summer Winter ~1.3 million km2 ~21 million km2 3 Examples of possible impacts on mammals Projected changes in the polar bear habitat of sea ice disappearance • Seals unlikely to survive (need sea ice to rest, give birth to and nurse their pups) • Polar bears unlikely to survive (need sea ice to hunt seals and move from one area to another) A polar bear near the coast of Spitsbergen. NY Times. Wikimedia Commons Sea ice plays an important role in Sea ice and albedo Earth’s climate system Albedo is the fraction of incoming solar energy that is reflected back to space by the Earth system. It ranges from 0 (darkest) to 1 (brightest). The National Snow and Ice Data Center NASA Meltwater ponds in Arctic summer Outline for this week Types of Ice Glacial ice - forms from the accumulation & compression of snow (land ice; source of icebergs) -Sea ice - Arctic and Antarctic sea ice - Glaciers, ice streams, and icebergs - Ice cores as paleoclimatic archives - Past climate - Sea-level history https://www.cbc.ca/news/canada/newfoundland‐labrador Sea ice - forms from the freezing of sea water and is floating on the surface of the ocean. Sea ice covers ~7% of the ocean but only 0.1% of Earth’s ice volume) 4 The conversion of freshly fallen snow into Ice movement through a glacier dense, crystalline glacial ice. zone of accumulation – lower limit is the equilibrium line zone of ablation – net loss by melting Accumulation Equilibrium line Ablation Ice flows under its own weight due to gravity. Accumulation zone Ablation zone Note the layers Athabasca Glacier, Columbia Icefields, Alberta Glacial mass balance determines Rate of movement advance vs. retreat – meters to 100s meters /year Zone of wastage (ablation) – area where there is a net loss to the glacier due to Melting Calving – breaking off of large pieces of ice into water (icebergs where the glacier has reached the sea) Glacial budget (mass balance) - Balance, or lack of balance, between accumulation at the upper end of the glacier, and loss at the lower end Ice advances if accumulation exceeds loss Ice front retreats if ablation increases and/or accumulation decreases Some glaciers may have rapid movements called surges. 5 Glacial retreat Erosional features and some depositional landforms Glaciers are capable of great erosion (by plucking and abrasion) and sediment transport During retreat, equilibrium line moves until a new balance achieved. Either way, ice within Glacial striation the glaciers continues to flow forward. Rocks in ice acting like sandpaper to smooth and polish the Glacial deposits surface below. Produces rock flour & glacial striations. Ice lifting of loosened blocks of rocks and freezing to the base of the glacier. Transports. Deposits. Glacial drift refers to all sediments of glacial origin. Till - material that is deposited directly by glacial ice. Till is a mixture of poorly sorted many different sediment sizes and striated rocks. The most common features created by glacial deposition are layers or ridges of till, called moraines. http://hugefloods.com/Lake-Missoula-Rock-Flour.html Associated with valley glaciers are lateral moraines, formed along the sides of the valley, and medial moraines, formed between two valley glaciers that have joined. Kaskawulsh Glacier, Yukon Lateral 35 6 Terminal (or end) moraines mark the Glacial erratics furthest (former) advance of the glacier. Ice-transported boulder, not derived from underlying bedrock. Mt Lawson, BC Erratic boulders Okotok, AB 38 Erosional features and some depositional Glaciers landforms classified by size (& location) … valley glaciers vs. ice sheets valley glacier at Mount Logan Glacial erratic rock, Rice County, MN Valley (AKA: alpine) glaciers. Exist in mountainous areas https://mountainbikegeezer.com/woolly-bike-clubs-new-erratic-rock-trail/camerazoom-20141017151511634/ Each flows down a valley from an accumulation area near its head Tributary & valley glaciers Continental ice sheets: Antarctica Currently two major ice sheets - Greenland & Antarctica. Ice flows out in all directions from snow accumulation areas. Floating ice shelves extend from Antarctica. 42 7 Ice stream 2002 Breakup of Larson B Ice Shelf (fast flowing part [1 km/yr] of an ice sheet) (area about RI) More complicated than just warming (Ross Sea info) Ice stream Crevasse, fissure or crack in a glacier resulting from stress produced by movement. (Ross Sea info) alving (YouTube: Chasing Ice) Edge of Tabular Iceberg (like this from Larson B) An iceberg is a large piece of freshwater ice that has broken off a glacier or an ice shelf and is floating freely in open water. Small pieces of crumbling icebergs are called "growlers" or "bergy bits". https://www.jamstec.go.jp/e/about/press_release/20141027/ 8 Sea ice vs. Icebergs Some differences Sea ice: 1) Formed from seawater 2) Rejects salt but still contains some salt 3) Flat, thin; ice-breakers can break 4) Ice lasts seasonally up to a few years Icebergs: 1) Formed on land from freshwater 2) No salt 3) Calved from outlet glaciers; bulky 4) Many (even hundreds of) years of accumulated ice Calving Ice cores as paleoclimate archive Ice coring An ice core station in Antarctica (Sverdrup, 2006) (Sverdrup, 2006) Ice core processing Polar ice cores (Sverdrup, 2006) The Greenland Ice Sheet Project YouTube: Ancient Ice Reveals Earth's Climate History 9 Summary • Sea ice - seasonal, multi-year ice formed from seawater - shrinking and thinning in the Arctic - Arctic vs. Antarctic • Glaciers and icebergs Know the difference between icebergs and sea ice • Glaciers work as systems that respond to climate Mass balance controls advance & retreat; ice flows Erosional features & depositional landforms • Ice streams - a region of an ice sheet that moves significantly faster than the surrounding ice • Ice cores - paleoclimate archive from poles and tropical mountains - past variations in CO2, ice age, and local temperature correlate well Petit e al., 1999 (redrawn Sigman & Boyle) 10.
Recommended publications

  • 100 Magic Water Words

    WaterCards.(WebFinal).qxp 6/15/06 8:10 AM Page 1 estuary ocean backwater canal ice flood torrent snowflake iceberg wastewater 10 0 ripple tributary pond aquifer icicle waterfall foam creek igloo cove Water inlet fish ladder snowpack reservoir sleet Words slough shower gulf rivulet salt lake groundwater sea puddle swamp blizzard mist eddy spillway wetland harbor steam Narcissus surf dew white water headwaters tide whirlpool rapids brook 100 Water Words abyssal runoff snow swell vapor EFFECT: Lay 10 cards out blue side up. Ask a participant to mentally select a word and turn the card with the word on it over. You turn all marsh aqueduct river channel saltwater the other cards over and mix them up. Ask the participant to point to the card with his/her water table spray cloud sound haze word on it. You magically tell the word selected. KEY: The second word from the top on the riptide lake glacier fountain spring white side is a code word for a number from one to ten. Here is the code key: Ocean = one (ocean/one) watershed bay stream lock pool Torrent = two (torrent/two) Tributary = three (tributary/three) Foam = four (foam/four) precipitation lagoon wave crest bayou Fish ladder = five (fish ladder/five) Shower = six (shower/six) current trough hail well sluice Sea = seven (sea/seven) Eddy = eight (eddy/eight) Narcissus = nine (Narcissus/nine) salt marsh bog rain breaker deluge Tide = ten (tide/ten) Notice the code word on the card that is first frost downpour fog strait snowstorm turned over. When the second card is selected the chosen word will be the secret number inundation cloudburst effluent wake rainbow from the top.
  • In the United States District Court for the District of Maine

    In the United States District Court for the District of Maine

    Case 2:21-cv-00154-JDL Document 1 Filed 06/14/21 Page 1 of 13 PageID #: 1 IN THE UNITED STATES DISTRICT COURT FOR THE DISTRICT OF MAINE ICE CASTLES, LLC, a Utah limited liability company, Plaintiff, COMPLAINT vs. Case No.: ____________ CAMERON CLAN SNACK CO., LLC, a Maine limited liability company; HARBOR ENTERPRISES MARKETING AND JURY TRIAL DEMANDED PRODUCTION, LLC, a Maine limited liability company; and LESTER SPEAR, an individual, Defendants. Plaintiff Ice Castles, LLC (“Ice Castles”), by and through undersigned counsel of record, hereby complains against Defendants Cameron Clan Snack Co., LLC; Harbor Enterprises Marketing and Production, LLC; and Lester Spear (collectively, the “Defendants”) as follows: PARTIES 1. Ice Castles is a Utah limited liability company located at 1054 East 300 North, American Fork, Utah 84003. 2. Upon information and belief, Defendant Cameron Clan Snack Co., LLC is a Maine limited liability company with its principal place of business at 798 Wiscasset Road, Boothbay, Maine 04537. 3. Upon information and belief, Defendant Harbor Enterprises Marketing and Production, LLC is a Maine limited liability company with its principal place of business at 13 Trillium Loop, Wyman, Maine 04982. Case 2:21-cv-00154-JDL Document 1 Filed 06/14/21 Page 2 of 13 PageID #: 2 4. Upon information and belief, Defendant Lester Spear is an individual that resides in Boothbay, Maine. JURISDICTION AND VENUE 5. This is a civil action for patent infringement arising under the Patent Act, 35 U.S.C. § 101 et seq. 6. This Court has subject matter jurisdiction over this controversy pursuant to 28 U.S.C.
  • SAR Image Wave Spectra to Retrieve the Thickness of Grease-Pancake

    SAR Image Wave Spectra to Retrieve the Thickness of Grease-Pancake

    www.nature.com/scientificreports OPEN SAR image wave spectra to retrieve the thickness of grease‑pancake sea ice using viscous wave propagation models Giacomo De Carolis 1*, Piero Olla2,3 & Francesca De Santi 1 Young sea ice composed of grease and pancake ice (GPI), as well as thin foes, considered to be the most common form of sea ice fringing Antarctica, is now becoming the “new normal” also in the Arctic. A study of the rheological properties of GPI is carried out by comparing the predictions of two viscous wave propagation models: the Keller model and the close‑packing (CP) model, with the observed wave attenuation obtained by SAR image techniques. In order to ft observations, it is shown that describing GPI as a viscous medium requires the adoption of an ice viscosity which increases with the ice thickness. The consequences regarding the possibility of ice thickness retrieval from remote sensing data of wave attenuation are discussed. We provide examples of GPI thickness retrievals from a Sentinel‑1 C band SAR image taken in the Beaufort Sea on 1 November 2015, and three CosmoSkyMed X band SAR images taken in the Weddell Sea on March 2019. The estimated GPI thicknesses are consistent with concurrent SMOS measurements and available local samplings. Climate change has led in the last decade to a dramatic reduction in the extent and the thickness of sea ice in the Arctic region during the summer season. As a result, the marginal ice zone (MIZ), which is the dynamic transition region separating the ice pack from the open ocean, has become increasingly exposed to the wind and the wave actions1,2.
  • 30-2 Lee2.Pdf

    30-2 Lee2.Pdf

    OceTHE OFFICIALa MAGAZINEn ogOF THE OCEANOGRAPHYra SOCIETYphy CITATION Lee, C.M., J. Thomson, and the Marginal Ice Zone and Arctic Sea State Teams. 2017. An autonomous approach to observing the seasonal ice zone in the western Arctic. Oceanography 30(2):56–68, https://doi.org/10.5670/oceanog.2017.222. DOI https://doi.org/10.5670/oceanog.2017.222 COPYRIGHT This article has been published in Oceanography, Volume 30, Number 2, a quarterly journal of The Oceanography Society. Copyright 2017 by The Oceanography Society. All rights reserved. USAGE Permission is granted to copy this article for use in teaching and research. Republication, systematic reproduction, or collective redistribution of any portion of this article by photocopy machine, reposting, or other means is permitted only with the approval of The Oceanography Society. Send all correspondence to: [email protected] or The Oceanography Society, PO Box 1931, Rockville, MD 20849-1931, USA. DOWNLOADED FROM HTTP://TOS.ORG/OCEANOGRAPHY SPECIAL ISSUE ON AUTONOMOUS AND LAGRANGIAN PLATFORMS AND SENSORS (ALPS) An Autonomous Approach to Observing the Seasonal Ice Zone in the Western Arctic By Craig M. Lee, Jim Thomson, and the Marginal Ice Zone and Arctic Sea State Teams 56 Oceanography | Vol.30, No.2 ABSTRACT. The Marginal Ice Zone and Arctic Sea State programs examined the MIZ is a region of complex atmosphere- processes that govern evolution of the rapidly changing seasonal ice zone in the Beaufort ice-ocean dynamics that varies with sea Sea. Autonomous platforms operating from the ice and within the water column ice properties and distance from the ice collected measurements across the atmosphere-ice-ocean system and provided the edge (Figure 2; e.g., Morison et al., 1987).
  • Drift of Pancake Ice Floes in the Winter Antarctic Marginalicezoneduringpolarcyclones

    Drift of Pancake Ice Floes in the Winter Antarctic Marginalicezoneduringpolarcyclones

    DRIFT OF PANCAKE ICE FLOES IN THE WINTER ANTARCTIC MARGINAL ICE ZONE DURING POLAR CYCLONES APREPRINT Alberto Alberello∗ Luke Bennetts Petra Heil University of Adelaide University of Adelaide Australian Antarctic Division & ACE–CRC 5005, Adelaide, Australia 5005, Adelaide, Australia 7001, Hobart, Australia Clare Eayrs Marcello Vichi Keith MacHutchon New York University Abu Dhabi University of Cape Town University of Cape Town Abu Dhabi, United Arab Emirates Rondenbosch, 7701, South Africa Rondenbosch, 7701, South Africa Miguel Onorato Alessandro Toffoli Università di Torino & IFNF The University of Melbourne Torino, 10125, Italy 3010, Parkville, Australia June 27, 2019 ABSTRACT High temporal resolution in–situ measurements of pancake ice drift are presented, from a pair of buoys deployed on floes in the Antarctic marginal ice zone during the winter sea ice expansion, over nine days in which the region was impacted by four polar cyclones. Concomitant measurements of wave-in-ice activity from the buoys is used to infer that pancake ice conditions were maintained over at least the first seven days. Analysis of the data shows: (i) unprecedentedly fast drift speeds in the Southern Ocean; (ii) high correlation of drift velocities with the surface wind velocities, indicating absence of internal ice stresses >100 km in from the edge in 100% remotely sensed ice concentration; and (iii) presence of a strong inertial signature with a 13 h period. A Langrangian free drift model is developed, including a term for geostrophic currents that reproduces the 13 h period signature in the ice motion. The calibrated model is shown to provide accurate predictions of the ice drift for up to 2 days, and the calibrated parameters provide estimates of wind and ocean drag for pancake floes under storm conditions.
  • Glossary of Marine Navigation 792

    Glossary of Marine Navigation 792

    GLOSSARY OF MARINE NAVIGATION 792 ice fog. Fog composed of suspended particles of ice, partly ice crystals 20 to 100 microns in diameter but chiefly, especially when dense, droxtals 12 to 20 microns in diameter. It occurs at very low temper- atures, and usually in clear, calm weather in high latitudes. The sun I is usually visible and may cause halo phenomena. Ice fog is rare at temperatures warmer than -30° C or -20°F. Also called RIME FOG. See also FREEZING FOG. IALA Maritime Buoyage System. A uniform system of maritime buoy- icefoot, n. A narrow fringe of ice attached to the coast, unmoved by tides age which is now implemented by most maritime nations. Within and remaining after the fast ice has moved away. the single system there are two buoyage regions, designated as Re- ice-free, adj. Referring to a locale with no sea ice; there may be some ice gion A and Region B, where lateral marks differ only in the colors of port and starboard hand marks. In Region A, red is to port on en- of land origin present. tering; in Region B, red is to starboard on entering. The system is a ice front. The vertical cliff forming the seaward face of an ice shelf or oth- combined cardinal and lateral system, and applies to all fixed and er floating glacier varying in height from 2 to 50 meters above sea floating marks, other than lighthouses, sector lights, leading lights level. See also ICE WALL. and marks, lightships and large navigational buoys. ice island.
  • The Roland Von Glasow Air-Sea-Ice Chamber (Rvg-ASIC)

    The Roland Von Glasow Air-Sea-Ice Chamber (Rvg-ASIC)

    https://doi.org/10.5194/amt-2020-392 Preprint. Discussion started: 14 October 2020 c Author(s) 2020. CC BY 4.0 License. The Roland von Glasow Air-Sea-Ice Chamber (RvG-ASIC): an experimental facility for studying ocean/sea-ice/atmosphere interactions Max Thomas1, James France1,2,3, Odile Crabeck1, Benjamin Hall4, Verena Hof5, Dirk Notz5,6, Tokoloho Rampai4, Leif Riemenschneider5, Oliver Tooth1, Mathilde Tranter1, and Jan Kaiser1 1Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, UK, NR4 7TJ 2British Antarctic Survey, Natural Environment Research Council, Cambridge CB3 0ET, UK 3Department of Earth Sciences, Royal Holloway, University of London, Egham TW20 0EX, UK 4Chemical Engineering Deptartment, University of Cape Town, South Africa 5Max Planck Institute for Meteorology, Hamburg, Germany 6Center for Earth System Research and Sustainability (CEN), University of Hamburg, Germany Correspondence: Jan Kaiser ([email protected]) Abstract. Sea ice is difficult, expensive, and potentially dangerous to observe in nature. The remoteness of the Arctic and Southern Oceans complicates sampling logistics, while the heterogeneous nature of sea ice and rapidly changing environmental conditions present challenges for conducting process studies. Here, we describe the Roland von Glasow Air-Sea-Ice Chamber (RvG-ASIC), a laboratory facility designed to reproduce polar processes and overcome some of these challenges. The RvG- 5 ASIC is an open-topped 3.5 m3 glass tank housed in a coldroom (temperature range: -55 to +30 oC). The RvG-ASIC is equipped with a wide suite of instruments for ocean, sea ice, and atmospheric measurements, as well as visible and UV lighting.
  • A Tale of Three Sisters: Reconstructing the Holocene Glacial History and Paleoclimate Record at Three Sisters Volcanoes, Oregon, United States

    A Tale of Three Sisters: Reconstructing the Holocene Glacial History and Paleoclimate Record at Three Sisters Volcanoes, Oregon, United States

    Portland State University PDXScholar Dissertations and Theses Dissertations and Theses 2005 A Tale of Three Sisters: Reconstructing the Holocene glacial history and paleoclimate record at Three Sisters Volcanoes, Oregon, United States Shaun Andrew Marcott Portland State University Follow this and additional works at: https://pdxscholar.library.pdx.edu/open_access_etds Part of the Geology Commons, and the Glaciology Commons Let us know how access to this document benefits ou.y Recommended Citation Marcott, Shaun Andrew, "A Tale of Three Sisters: Reconstructing the Holocene glacial history and paleoclimate record at Three Sisters Volcanoes, Oregon, United States" (2005). Dissertations and Theses. Paper 3386. https://doi.org/10.15760/etd.5275 This Thesis is brought to you for free and open access. It has been accepted for inclusion in Dissertations and Theses by an authorized administrator of PDXScholar. Please contact us if we can make this document more accessible: [email protected]. THESIS APPROVAL The abstract and thesis of Shaun Andrew Marcott for the Master of Science in Geology were presented August II, 2005, and accepted by the thesis committee and the department. COMMITTEE APPROVALS: (Z}) Representative of the Office of Graduate Studies DEPARTMENT APPROVAL: MIchael L. Cummings, Chair Department of Geology ( ABSTRACT An abstract of the thesis of Shaun Andrew Marcott for the Master of Science in Geology presented August II, 2005. Title: A Tale of Three Sisters: Reconstructing the Holocene glacial history and paleoclimate record at Three Sisters Volcanoes, Oregon, United States. At least four glacial stands occurred since 6.5 ka B.P. based on moraines located on the eastern flanks of the Three Sisters Volcanoes and the northern flanks of Broken Top Mountain in the Central Oregon Cascades.
  • Steelhead Use of Icicle Creek: a Review ______

    Steelhead Use of Icicle Creek: a Review ______

    U.S. Fish and Wildlife Service Steelhead Use of Icicle Creek: A Review ______________________________________________________________________________ Matt Hall, William Gale, and Malenna Cappellini U.S. Fish and Wildlife Service Mid-Columbia River Fisheries Resource Office Leavenworth, WA 98826 On the cover: Oncorhynchus mykiss caught in a screw trap in the Entiat River. USFWS The correct citation for this report is: Hall, M, W. Gale, and M. Cappellini. 2014. Steelhead Use of Icicle Creek: A Review. U.S. Fish and Wildlife Service. Leavenworth WA. STEELHEAD USE OF ICICLE CREEK: A REVIEW Authored by Matt Hall, William Gale, and Malenna Cappellini U.S. Fish and Wildlife Service Mid-Columbia River Fisheries Resource Office 7501 Icicle Road Leavenworth, WA 98826 Final May 21, 2014 Disclaimers Any findings and conclusions presented in this report are those of the authors and may not necessarily represent the views of the U.S. Fish and Wildlife Service. The mention of trade names or commercial products in this report does not constitute endorsement or recommendation for use by the federal government. Table of Contents List of Tables ..................................................................................................................................v List of Figures ................................................................................................................................ ii Introduction ....................................................................................................................................1
  • Satellite Observations for Detecting and Forecasting Sea-Ice Conditions: a Summary of Advances Made in the SPICES Project by the EU’S Horizon 2020 Programme

    Satellite Observations for Detecting and Forecasting Sea-Ice Conditions: a Summary of Advances Made in the SPICES Project by the EU’S Horizon 2020 Programme

    remote sensing Article Satellite Observations for Detecting and Forecasting Sea-Ice Conditions: A Summary of Advances Made in the SPICES Project by the EU’s Horizon 2020 Programme Marko Mäkynen 1,* , Jari Haapala 1, Giuseppe Aulicino 2 , Beena Balan-Sarojini 3, Magdalena Balmaseda 3, Alexandru Gegiuc 1 , Fanny Girard-Ardhuin 4, Stefan Hendricks 5, Georg Heygster 6, Larysa Istomina 5, Lars Kaleschke 5, Juha Karvonen 1 , Thomas Krumpen 5, Mikko Lensu 1, Michael Mayer 3,7, Flavio Parmiggiani 8 , Robert Ricker 4,5 , Eero Rinne 1, Amelie Schmitt 9 , Markku Similä 1 , Steffen Tietsche 3 , Rasmus Tonboe 10, Peter Wadhams 11, Mai Winstrup 12 and Hao Zuo 3 1 Finnish Meteorological Institute, PB 503, FI-00101 Helsinki, Finland; jari.haapala@fmi.fi (J.H.); alexandru.gegiuc@fmi.fi (A.G.); juha.karvonen@fmi.fi (J.K.); mikko.lensu@fmi.fi (M.L.); eero.rinne@fmi.fi (E.R.); markku.simila@fmi.fi (M.S.) 2 Department of Science and Technology—DiST, Università degli Studi di Napoli Parthenope, Centro Direzionale Is C4, 80143 Napoli, Italy; [email protected] 3 European Centre for Medium-Range Weather forecasts, Shinfield Park, Reading RG2 9AX, UK; [email protected] (B.B.-S.); [email protected] (M.B.); [email protected] (M.M.); steff[email protected] (S.T.); [email protected] (H.Z.) 4 Ifremer, Univ. Brest, CNRS, IRD, Laboratoire d’Océanographie Physique et Spatiale, IUEM, 29280 Brest, France; [email protected] 5 AlfredWegener Institute, Am Handelshafen 12, 27570 Bremerhaven, Germany; [email protected] (S.H.);
  • A Free-Boundary Theory for the Shape of the Ideal Dripping Icicle Martin B

    A Free-Boundary Theory for the Shape of the Ideal Dripping Icicle Martin B

    PHYSICS OF FLUIDS 18, 083101 ͑2006͒ A free-boundary theory for the shape of the ideal dripping icicle Martin B. Short Department of Physics, University of Arizona, Tucson, Arizona 85721 James C. Baygents Department of Chemical and Environmental Engineering and Program in Applied Mathematics, University of Arizona, Tucson, Arizona 85721 ͒ Raymond E. Goldsteina Department of Physics, Program in Applied Mathematics, and BIO5 Institute, University of Arizona, Tucson, Arizona 85721 ͑Received 16 January 2006; accepted 10 July 2006; published online 18 August 2006͒ The growth of icicles is considered as a free-boundary problem. A synthesis of atmospheric heat transfer, geometrical considerations, and thin-film fluid dynamics leads to a nonlinear ordinary differential equation for the shape of a uniformly advancing icicle, the solution to which defines a parameter-free shape which compares very favorably with that of natural icicles. Away from the tip, the solution has a power-law form identical to that recently found for the growth of stalactites by precipitation of calcium carbonate. This analysis thereby explains why stalactites and icicles are so similar in form despite the vastly different physics and chemistry of their formation. In addition, a curious link is noted between the shape so calculated and that found through consideration of only the thin coating water layer. © 2006 American Institute of Physics. ͓DOI: 10.1063/1.2335152͔ The formation of patterns in snow and ice has been a boundary layer in the surrounding air through which latent source of fascination since antiquity. As early as 1611, Jo- heat is transported by diffusion and convection.
  • Ice Dams and Icicles Presented By: Steve Norwood, AIA Norwood Architecture, Inc

    Ice Dams and Icicles Presented By: Steve Norwood, AIA Norwood Architecture, Inc

    Ice Dams and Icicles Presented by: Steve Norwood, AIA Norwood Architecture, Inc. 363 Centennial Pkwy, #150 Louisville, CO 80027 (303)-664-1528 www.norwoodarchitecture.com © 2011 Norwood Architecture, Inc. 363 Centennial Pkwy #150 Louisville, CO (303)-664-1528 www.norwoodarchitecture.com 1 INTRODUCTION: o Roofs that drain to cold eaves may experience ice dams and icicles at their roof eaves and gutters in winter1. o Water that ponds upslope of ice dams may leak into the building envelope2. o Ice dams and icicles can create problems and hazards for building structures and their occupants. fig. A © 2011 Norwood Architecture, Inc. 363 Centennial Pkwy #150 Louisville, CO (303)-664-1528 www.norwoodarchitecture.com 2 ICE DAM: o An ice dam is the accumulation of thick layers of ice at roof eaves and gutters that results from periodic melting of snow over warmer areas of roof flowing down and re-freezing at the colder eaves and overhangs. fig. B © 2011 Norwood Architecture, Inc. 363 Centennial Pkwy #150 Louisville, CO (303)-664-1528 www.norwoodarchitecture.com 3 ICICLE: o An icicle is a spike of ice formed when water dripping or falling from an object freezes3. o Icicles form when ice or snow melts and then re-freezes at the eave3. fig. C © 2011 Norwood Architecture, Inc. 363 Centennial Pkwy #150 Louisville, CO (303)-664-1528 www.norwoodarchitecture.com 4 COLD REGIONS o Icings typically do not form when outside temperatures are above 22° F 2. When it is warmer than 22° F outside, meltwater seldom re-freezes at roof eaves4. o Snow is an insulator.