Lecture1

Slide1: 

Welcome to

Slide7: 

We will cover both poles…… Hey where’s Santa? Not here!

Slide8: 

Have any of you been to a polar region?

Slide10: 

A previous student

My Course Philosophy: 

My Course Philosophy Interaction Web Classmates Instructor Discussion Questions Better to sound like a fool than to be a fool De-emphasize “facts” - Emphasize “concepts” Should not need to take a lot of written notes I offer a

E-mail me anywhere anytime anyplace: 

E-mail me anywhere anytime anyplace pguest@nps.navy.mil Office: 259 Root Hall Office Hours: Anytime or by appointment

Course Outline: 

Course Outline Go to Course Web site at http://www.weather.nps.navy.mil/~psguest/OC3212/ Available from my home page: http://www.weather.nps.navy.mil/~psguest/

Unfortunately………..: 

Unfortunately……….. I am required to give out This portion will count 1/3 toward your final OC/MR 3212 Grade I will let you decide by majority vote how you want to be graded Two choices: “Quiz (Monday of finals week)” “Mini-project”

Mini-project ideas: 

Mini-project ideas Climate model sensitivity study using FASTCLIMATE Website review/improvements Make up some more study questions Suggestions for improvement Suggestions for making available and usable to the fleet Create you own web pages to add to this site or Your own paper on a polar met-related topic Paper review Other ideas? ~4+ pages text (double space) or 2-3+ “nice” usable Web pages Improve the Polar Meteorology Web Site

General Course Goals(Page 1 of Notes): 

General Course Goals (Page 1 of Notes) Description Know the general features and processes of the Arctic and Antarctic Atmosphere Science Understand the causes of atmospheric phenomena in Arctic and Antarctic regions Practical Forecasting (not emphasized) Ship and aircraft operations RF propagation

Slide17: 

Why study Polar Meteorology? The Arctic is strategically important. Submarines Surface Vessels Missiles Aircraft Post-cold-war emphasis on “global” Navy includes Arctic Regions Ship and Aircraft operations affected by severe meteorological conditions Icing Severe Storms RF Propagation Lack of Experience by US Navy in cold weather operations Military Reasons:

Scientific Reasons:: 

Scientific Reasons: Climate There is a strong link between global climate and polar processes Melting of the Arctic Ocean Collapse of Antactic ice shelves Pollution Arctic haze Ozone hole Antarctica is the focus of much scientific attention Undisturbed, relatively pristine environment serves as a “benchmark” |Could happen in near future

Economic Reasons: : 

Economic Reasons:   Transportation Many aircraft flights cross Arctic region Ground transportation significantly affected by weather   Fossil Fuel Extraction - Arctic Designing oil platforms in sea-ice areas Stopping drilling before severe weather events   Biological resources - facing serious depletions Fishing, Sealing, Bottom life   Regions or countries most dependent on Arctic resources: Russia, Canada, Scandinavia, Alaska, Greenland   Antarctica Vast mineral resources, currently not exploited Southern Sea has very high biological productivity

Slide20: 

How would you like to be… Right there? __________ Reading from Streamlines Magazine An experience from the Ocean drilling vessel Resolution

Slide21: 

Check out chapters 1 and 2 in class notes, Appendix A (will not be on exam) Reading from US Navy Bulletin on Cold Weather Operations Ships: USS Kirk USS Carl Vinson

Slide22: 

There are two types of icing which can occur on vessels in cold weather regions: Atmospheric Icing Sea-Spray Icing The most severe type and the topic of the rest of this talk Required assignment: Read the Icing section of the Polar Meteorology Web Module Do the on-line study questions

Todays Lecture Topic: Sea-spray Vessel Icing: 

Todays Lecture Topic: Sea-spray Vessel Icing . Vessel Icing from Sea-Spray Description Prediction Mitigation

Description of Sea-Spray IcingEffects and Causes: 

Description of Sea-Spray Icing Effects and Causes Effects Serious hazard for marine operations on polar regions Many lives and ships have been lost after ships sank or became disabled, after the accretion of ice on decks and superstructures.

More Effects: 

More Effects Extra weight from ice accretion can cause capsizing extreme rolling and pitching topside flooding Particular dangerous Fishing vessels and other small ships US Navy ships with high superstructures and low freeboard FF, FFG, CG, CGN, DD and DDG types Web Site Example Web Site Pictures

Causes of Vessel Icing: 

Causes of Vessel Icing . Environmental Vessel Characteristics

Environmental Factors: 

Environmental Factors 1. Wind Speed 2. Air Temperature 3. Water Temperature 4. Freezing Temperature of Water 5. Wind Direction, Relative to the Ship 6. Swell and Wave Characteristics Wave Size Wave Length Wave Propagation Direction

Three Ingredients:: 

Three Ingredients: 1. High Wind Speed - Usually above 18 kts or 9 m/s but sometimes lower 2. Low Air Temperature - Below freezing (-1.7 oC or 29 oF) 3. Low Water Temperature - Usually below 7 oC or 45 oF The first two occur during periods of:

What is the hallmark of cold advection over the ocean?: 

What is the hallmark of cold advection over the ocean? Cloud Streets Hint: Easily visible from satellites

Regions where icing is most likely to occur : 

Regions where icing is most likely to occur Nordic Seas Nordic Seas Labrador Sea Labrador Sea Gulf of Alaska Gulf of Alaska Bering Strait Bering Strait Sea of Okhotsk Sea of Okhotsk

Slide31: 

Also: Southern Seas around Antarctica (Been there done that!) Great Lakes Black Sea Baltic Sea All Marginal Ice Zones Wherever water is < 5 C

Vessel Characteristics: 

Vessel Characteristics 1. Ship Speed 2. Ship Heading (with respect to wind, waves and swell) 3. Ship Length 4. Ship Freeboard 5. Ship Handling 6. Ship Cold Soaking

Slide33: 

Threshold Wind Speeds for Icing to Occur on Various Length Ships

Slide34: 

The chart is only a rough guide for ships steaming into the wind and waves. The actual potential for icing depends on the type, load, and handling characteristics of a particular ship. Any captain or bridge officer who is familiar with a ship should be well aware of the wind speeds which cause sea spray to reach the deck and superstructure, and should base his/her assessment on the potential for icing on this knowledge. The previous table was based on sea-keeping theory. See class notes for details…

Slide35: 

Predicting Vessel Icing Can Icing be predicted? Fortunately…. Yes

Forecasting AlogorithmDeveloped by Jim Overland: 

Forecasting Alogorithm Developed by Jim Overland Based on vessels 20 to 75 meters in length PPR = Icing Predictor (moCs-1) Va = Wind Speed (m s-1) Tf = Freezing point of seawater (usually -1.7 oC or -1.8 oC) Ta = Air Temperature (oC) Tw = Sea Temperature (oC)

Forecast Product: 

Forecast Product Based on Overland’s algorithm Not clear what synoptic model is used Available on FAX and WWW http://polar.wwb.noaa.gov/vessel.icing/ NCEP OMP Superstructure Ice Accretion Guidance

Avoidance and Mitigation of Vessel Sea Spray Icing: 

Avoidance and Mitigation of Vessel Sea Spray Icing Avoid situations with : 1. Cold Air Advection 2. Cold Sea Temperatures Use the forecast guides shown previously… They are quite accurate. Be especially wary of Polar Lows. They are often associated with severe icing

Ship Manuevers: 

Ship Manuevers Seek Immediate Shelter In harbor Lee of Island of other land mass Get close to ice edge If no shelter available: Steam downwind Adjust speed and direction to minimize sea spray Do not wait until ice accreation becomes serious Turning a ice-weighted ship through the trough can be deadly

Preventative Coatings: 

Preventative Coatings 1. Flourocarbon penetrating coating (FPC). 2. Vellox 140 Problems: They wash off easily… They are slippery… They are hazardous materials… They cannot be used everywhere: Focus on critical areas Use to faciliate physical removal

Ice and Snow Removal Methods:Physical Removal: 

Ice and Snow Removal Methods: Physical Removal Essential for removing ice: Baseball Bat or Large Wooden Mallet

Slide44: 

Thin deck ice Thicker ice Snow Also useful : Steel-bladed ice scrapers Straight bottom shovels Spades Hoes Picks Brooms Snow shovels > ) > Physical Removal

Ice and Snow Removal Methods:Chemical Removal: 

Ice and Snow Removal Methods: Chemical Removal Rock Salt (Sodium Chloride)    Most economical Calcium Chloride    Faster acting than rock salt Urea     Less corrosive than above Ethylene Glycol Sprays Methanol Other light de-icers including alcohols

Other Ice and Snow Removal Methods:: 

Other Ice and Snow Removal Methods: Portable hot air guns Small ice deposits and spot thawing of pipes Electric hair driers Same uses as 1. Steam lances 4. A6 Jet Aircraft

Vessel Icing Conclusions: 

Vessel Icing Conclusions Topside vessel icing is primarily from wave-generated spray. Function of vessel length and shape. Avoid cold water areas where cold air advection is forecast. Be prepared!