Ice Storm Of 1998 Essay Research Paper

Ice Storm Of 1998 Essay, Research Paper

INTRODUCTION

Ice storms, also referred to as glaze storms, cause considerable damage every year to trees in urban and natural areas. They vary considerably in their severity and frequency. Ice storms are result of the ice formation process, which is influenced by general weather patterns. Ice accumulates when super cooled rain freezes on contact with surfaces, such as tree branches, that are at or below the freezing point (0′C). This generally occurs when a winter warm front passes through an area after the ground-level temperature reaches or falls below freezing. Rain falls through layers of cooler air without freezing, becoming super cooled. Periodically, other climatic events, including stationary, occluded, and cold fronts, also result in ice storms.

The purpose of this paper is to gain a better understanding of the1998 ice storm. This paper features three main section: An introduction, the main body (damage to woodland), and finally, a conclusion. In the main body of this paper, the effect of fire and pest/disease is discussed in detail. In the conclusion, comparison is made between fire and pests/disease versus ice storm. By the end of this paper, one should gain a better understanding of the severity of the 1998 ice storm as well as other damaging agents that affect the woodland in eastern North America

THE WORST STORM IN CANADIAN HISTORY

Ice storms are often winter’s worst hazard. More slippery than snow, freezing rain or glaze is tough and tenacious, clinging to every object it touches. A little can be dangerous, a lot can be catastrophic. Ice storm in Northeastern America has been common but the 1998 ice storm was exceptional.

Ice storms are a major hazard in all parts of Canada except the North, but are especially common from Ontario to Newfoundland. The severity of ice storms depends largely on the accumulation of ice, the duration of the event, and the location and extent of the area affected. Based on these criteria, Ice Storm’98 was the worst ever to hit Canada in recent memory. From January 5-10, 1998 the total water equivalent of precipitation, comprising mostly freezing rain and ice pellets and a bit of snow, exceeded 85 mm in Ottawa, 73 mm in Kingston, 108 in Cornwall and 100 mm in Montreal (Environmental Canada, Jan 12/1998). Previous major ice storms in the region, notably December 1986 in Ottawa and February 1961 in Montreal, deposited between 30 and 40 mm of ice – about half the thickness from the 1998 storm event! (Environmental Canada, Jan 12/1998).

The extent of the area affected by the ice was enormous. Freezing precipitation is often described as “a line of” or “spotty occurrences of”. At the peak of the storm, the area of freezing precipitation extended from Muskoka and Kitchener in Ontario through eastern Ontario, western Quebec and the Eastern Townships to the Fundy coasts of New Brunswick and Nova Scotia.

What made the ice storm so unusual, though, was that it went on for so long. On average, Ottawa and Montreal receive freezing precipitation on 12 to 17 days a year. Each episode generally lasts for only a few hours at a time, for an annual average total between 45 to 65 hours. During Ice Storm’98, it did not rain continuously, however, the number of hours of freezing rain and drizzle was in excess of 80 – again nearly double the normal annual total.

DAMAGE TO WOODLANDS

One of the most appealing features of Eastern Ontario is the extensive forest cover. This is made up of woodlands of varying structure. These woodlands, as well as natural fencerows, windbreaks, and plantations of pine and poplar, dominate the landscape. Icing impacts may best be understood by treating spatially larger scales, starting with individual trees, proceeding to stands, and finally to forest landscapes.

Individual Trees

Ice damage to trees can range from mere breakage of a few twigs, to bending stems to the ground, to moderate crown loss, to outright breakage of the trunk. In the 1998 Northeastern ice storm, icing lasted long enough that many trees which were bent over had their crowns glued to the snow surface by the ice in many instances for as long as 3 weeks. Some of those trees actually erect posture after release from the snow, while many others remain bent over after 2 years. The severity of damage is generally believed to be closely related to the severity of winds following the heaviest ice accumulations. Damage varies across a range of severity and subtlety: minor branch breakage; major branch loss; bending over of crowns; root damages; breakage of trunks and in some hardwoods, trunks can be split.

Stands

Depending on the stand composition, the amount of ice accumulation, and the stand history, damage to stands can range from light and patchy to the total breakage of all mature stems. Complete flattening of stands occurred locally in the Northeaster 1998 storm. In response to more moderate damage, effects on stands could include: shifts in over story composition in favor of the most resistant trees; loss of stand growth until leaf area is restored; and loss of value of the growth due to staining or damage to stem form.

Landscapes

The term landscape refers to a group or a family of trees. I use the term vaguely because the size and composition of landscapes differ from region