Ice Storms: an In-Depth Look at the Causes, Effects, and Consequences W
Total Page：16
File Type：pdf, Size：1020Kb
ICE STORMS: AN IN-DEPTH LOOK AT THE CAUSES, EFFECTS, AND CONSEQUENCES W. Patrick Dryer, Jackie E. Ebert & Nicholas E. King Abstract Formation The Storm of 1998 Tens of thousands of trees were downed or severely damaged (Figure 5 &6). Agricultural losses exceeded one million dollars as farmers were unable Figure 1- Moisture is up- Figure 5 (left)- Counties highlighted in orange illustrate areas to electronically milk their cows. Areas in Maine, New York, Vermont, and Ice Storms are very remarkable and fascinating en- lifted until it reaches the where the general public is in need of assistance. Areas in red New Hampshire were declared federal disaster areas. Despite the severity of vironmental events. Many factors must be just so in freezing level where it illustrate counties that indviduals are in need of assistance the storm, there were only seven fatalities in the Northeastern United States. order for these amazing natural occurrences to form. turns to snow. The pre- after the 1998 ice storm. Air temperature, pressure, humidity, as well as prevail- cipitation then falls and ing winds and air mass movements are all important in through the warm front the creation of these potentially damaging hazards. An causing the snow to melt ice storm’s duration can last from a few hours to sev- and from rain. Rain that eral days. This project looks into the delicate forma- gets caught in strong tion, impacts, and general response to ice storms – downdrafts can become specifically with the 1998 ice storm which took place super cooled falling as from January 5th to January 10th in a large part of freezing rain. eastern Ontario, southwest Quebec, and the north eastern United States. http://www.weatherbuff.com/graphics/live_graphics/stormMature For six days in January of 1998, freezing rain cov- .jpg http://www.gismaps.fema.gov/2003graphics/dr1467/dec_1467.jpg http://www.na.fs.fed.us/fhp/ice/apple_tmb.jpg ered an extensive area including Ontario, Quebec, Figure 6- Ice Sheets cover http://www.eoearth.org/upload/thumb/d/d5/Satelite_im The formation of an ice storm relies entirely on the age_1998_storm.jpg/250px-Satelite_image_1998_stor New Brunswick, and parts of New York and England. agricultural products, lock- m.jpg storms ability to create conditions which produce freezing According to Environment Canada, more than 80 hours ing in moisture and sealing rain. These conditions are very precise and if are not http://en.wikipedia.org/wiki/Image:1998_Ice_Storm_map.png of freezing rain totaling more than four inches in some produce from the air. http://www.wrh.noaa.gov/images/pqr/ice.gif just so, the freezing rain will alter its molecular state into areas more than doubled the annual average rain fall. Figure 3 (above)- Freezing rain accumulations from January Figure 2- Icing damages plants by sealing leaves, stems and something more common, such as snow, sleet or simply The storm affected nearly 4 million people, leaving 4th to January 10th. buds from the air rain. them without power for more than a day, and 700,000 A major storm and flood event struck northern New Eng- This delicate dance between air temperature and people remained without power three weeks after the land and New York during the first two weeks of January . moisture begins with the advancing of moist, warm air in storm. Conservative estimates of damage costs 1998. Heavy rains associated with a warm moist air mass col- the form of a warm front. As this warm front smashes exceed one-half billion dollars from this storm. The ice lided with a layer of cold air (Figure 3), producing ice accu- into a mass of cold air it produces a classic vertical tem- storm of 1998 directly affected more people in Canada mulations in excess of three inches (Figure 4). The heavy perature inversion with warm air above cold. As the than any other previous weather event in recorded his- rainfall, exceeding four inches in some areas, combined with warm air rises over the cold air it begins to cool and con- tory. runoff from the melting snow pack to produce record flooding. dense. When this condensed air reaches the upper There were more than 80 hours of freezing rain, which nearly levels of the atmosphere it has now reached tempera- doubled the annual average. The freezing rain coated all out- tures well below freezing (Figure 1), forming crystallized door surfaces and landforms with 3-4 inches of ice (Figure ice which quickly grow into snowflakes. The snowflakes, 4). It destroyed the electric power infrastructure, toppled http://pages.videotron.com/nblair/ice2.jpg too heavy to stay in the atmosphere, fall to earth. At this trees, collapsed outdoor canopies, and threatened many Figure 7- Multiple large point, if the temperature of the air remains consistently lives. branches in a tree generally below freezing, the snow will fall to earth as snow. Nev- Tens of thousands of trees were downed or severely dam- leads to more breakage; heavy ertheless, if there is a warm enough and deep enough ice accumulation on a multi- http://www.criacc.qc.ca/assets/anatomy.gif aged (Figure 5 &6). Agricultural losses exceeded one million layer of air the snow will melt and continue to the ground dollars as farmers were unable to electronically milk their branched trunk may even as rain. For the raindrops to reach the ground as freez- Figure 4- The formation of the 1998 ice storm. Notice how many warm moist air- cows. Areas in Maine, New York, Vermont, and New Hamp- cause a tree to split in two. ing rain they must be supercooled – where the tempera- shire were declared federal disaster areas. Despite the se- ture of a water droplet must drop below 0 C (32 F) with- masses from the Gulf of Mexico collided with cold dry air from Canada resulting verity of the storm, there were only seven fatalities in the out freezing. This temperature not constant, but is spe- Northeastern United States. http://www.islandnet.com/~see/weather/elements/icestorm.htm cific for each droplets size and particulate matter con- in ice accumulating nearly three inches Figure 3- Temperature tent. The thickness and temperature, as with the warm thick in some areas. http://www.islandnet.com/~see/weather/elements/icestorm.htm inversion chart. Figure 2- Classic low-level tem- air mass, is critical in the cold air mass for the formation perature inversion of freezing rain (Figure 2). If the cold air mass is too Figure 10- Is thick or too cold it could alter the rain droplets into sleet a graph that or ice pellets. If the cold air mass is too warm or too thin shows the the rain could continue to the ground as rain, and remain stages of the that way unless it comes in contact with a surface tem- Black River perature well below freezing. following the For freezing rain to occur, warm air must be lifted, Ice Storm of cooled and crystallized into snowflakes. These snow- 1998. flakes then fall to earth, but not before experiencing two http://ny.water.usgs.gov/projects/flood98/black_q.gif more temporal changes. The flakes will pass through a http://www.msc-smc.ec.gc.ca/msb/Reports/Ice_Storm/IceStorm_e_low.pdf http://www.msc-smc.ec.gc.ca/msb/Reports/Ice_Storm/IceStorm_e_low.pdf warm layer of air that will melt them into rain droplets, With such extreme weathering a record Figure 8- Shows Quebec’s transmission power Figure 9 - Shows Quebec’s transmission power grid then finally pass through a cold layer of air that will need crest was observed on the Black River at grid before the storm. afterthe storm. Red areas show damaged power Watertown, NY. The river crested two feet to cool the droplets to freezing 0 C (32 F) without freez- lines. ing them (Figure 3). Then and only then is freezing rain above any previous record. Flooding exas- produced. This fragile coordination of air temperatures More than three million people in four states and two Canadian provinces were with- perated relief efforts by forcing the evacu- and moisture is critical for the creation of an ice storm. out electricity. Figures 7 and 8 map transmission lost throughout Quebec. In Maine, 80% ation of more than 1,000 homes and ne- of the state’s population lost electricity for more than two weeks. Without electricity resi- cessitating numerous road closures. Con- servative damage estimates from this http://www.hprcc.unl.edu/nebraska/06-12-31-9597.jpg dents were forced to find alternative ways of heating their homes, pumping water, trav- storm approach one-half billion dollars in Formation of ice on branches causes trees to bend and eling, and communicating. places excess stress on vulernable limbs. the U.S. Consequences Conclusion Figure 12-Ice Effect Animals active in the winter months are also quite vul- Ice storms, though infrequent, can on Powerlines. The nerable to ice storms (Figure 14). Starvation is a large be very deadly. The chances of expe- heavy ice can cause problem because animals, specifically deer and cattle, riencing an ice storm at peak destruc- powerlines to fall cannot get to food that has been covered with ice. Birds tion are slim, but that doesn’t rule out over. who cannot find shelter during an ice storm might find their their ever prevalent danger. Remain- feet frozen to whatever surface they perch on. Bird’s ing informed and prepared for this, wings also get covered in ice making flight an impossibility. and all environmental hazards is key Ground bound animals may also see certain death because for survival. http://nsidc.org/snow/gallery/ice_storm.jpg http://vortex.accuweather.com/adc2004/pu b/includes/columns/penstone/2007/ice.jpg frozen drifts enclose opening for escape.