|
New
England's |
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New
England's |
Acknowledgments
We also thank Bill Ross and Cynthia Gannett of the University of New Hampshire, Louise Tallman of Rye, NH, Steve Miller of the Seacoast Science Center, Rye, NH, Joy Gannett of Nottingham, NH, the Appalachian Mountain Club, and the Mount Washington Observatory.
We thank our colleagues at Plymouth State College’s Meteorology program and the Mount Washington observatory for stimulating discussion concerning climate and we look forward to future collaboration.
Mark Twickler, Jane Fithian, Frank Smith, Kathy Hibbard, Jeremy Edmunds, and Fay Rubin contributed greatly to the final production of this document.
© Copyright 1998 Climate Change Research Center
Table of Contents
Preface
Through this document, the Climate Change Research Center at the University of New Hampshire hopes to provide the New England public with an overview of climate change and some changes in the chemistry of the atmosphere that are so important to New England.
Understanding is the first step in dealing with change in climate and the chemistry of the atmosphere.
Greenhouse gases are, however, only part of the human-induced problem. Levels of sulfate aerosols (Figure 1.3), ozone and heavy metals, to mention only a few, have also changed dramatically over the last century. These by-products of human activity are important not only because they can affect climate, but also because they can lead to dramatic alterations in the quality of air and water.
While remarkable efforts are underway to determine the history and significance of the human influence on climate, atmospheric chemistry, and resource depletion, our understanding of climate change is still hampered by incomplete knowledge of the natural controls on climate. Mounting evidence points to the significance of a variety of natural climate forcing agents such as: solar variability, planetary orbital cycles, volcanic activity, and the internal dynamics of ocean circulation.
From studies of past climate recorded in a variety of natural media such as ice cores, tree rings and marine sediments, we know that these controls have produced significant changes in climate. Some of these changes have been extremely large and extremely fast (starting and ending in a few years). Several of the most dramatic of these changes in climate (Figure 1.4 ) occurred when glacier ice covered New England during the period ~100,000 to ~11,600 years ago.
More moderate versions of these so-called rapid climate change events continue even since the disappearance of glaciers from New England (during the last ~11,600 years). While less dramatic in magnitude than their glacial-age predecessors, these events had dramatic consequences for civilization. For example, the most recent of these events, the Little Ice Age (Figure 1.5 ), started AD1400-1420 and resulted in the disappearance of the Norse colonies from Greenland. Sea ice surrounded Greenland throughout most or all of the year during the Little Ice Age, preventing supply ships from Europe from reaching the colonies.
Dramatic changes in natural climate are clearly still with us today, as attested to by the extreme weather produced throughout much of the globe by the 1997/98 ENSO (El Niño Southern Oscillation). In New England, 1997/98 brought extremes in flooding and one of the most severe ice storms in recorded history. The significance of understanding the frequency of such events and predicting future climate is clear.
To understand the dynamic New England climate, it is important to have a basic understanding of the larger scale general circulation of the atmosphere. Figure 2.1 depicts the surface and upper air flow for the northern hemisphere, and there is an identical set of cells for the southern hemisphere. The Hadley Cell to the south primarily controls tropical and subtropical climates, and only indirectly influences climate in this region. The mid-latitudes, however, are dominated by westerly circulation at the surface, which is fed by the subsiding air from the Hadley Cell in the subtropics. These northward-directed winds are deflected to the right (toward the east) in this hemisphere because of the rotation of the earth. As a result, the zone of the "westerlies," which are winds that come from the west and blow toward the east, is created across the middle latitudes. At the other end of the spectrum, the polar easterlies dominate the very high latitudes and are made up of extremely cold air that is transported away from the polar region.
The westerlies and polar easterlies frequently converge between 40° and 60° N latitude. The boundary between these contrasting air-masses forms the polar front , which divides warm and moist air to the south from cold and dry air to the north. The jet stream resides aloft over this dividing line delineating the location of the polar front at earth’s surface. This dynamic boundary generally lies near New England and the region can fall on either side of the boundary at any time of the year, thereby shifting us frequently from one air-mass to another. In winter, the polar front is typically located on the south side of New England and the region is dominated by colder and drier air-masses from Canada. In summer, the polar front relocates farther north, placing New England south of the boundary in warm and more humid air (Figure 2.1 ). This is one of the reasons that New England seasons are so distinct. New England summers are not that dissimilar from locations much farther to the south, e.g., Miami, Atlanta, or Washington, D.C., because these areas are typically all imbedded in the same air-mass. These locations can differ greatly in winter, however, when New England mostly falls on the north side of the polar front. It is also important to realize that the polar front is always shifting, and New England can find itself basking in warm and humid air even in winter, but these incursions are infrequent at that time of year.
There are four important components that dominate New England climate, some of which relate to the previous discussion. First, the area is located about half-way between the equator and the north pole, which is why it serves as a battleground for warm-moist air from the south and cold-dry air from the north. The surface air-mass boundaries are made up of warm, cold, and stationary fronts, which frequently traverse the region, bringing us from one air-mass to another in rapid succession. Second, the region is dominated by a cold water current along its east coast (coastal Maine, New Hampshire, and eastern Massachusetts) and a warm water current along the south shore (coastal Connecticut, Rhode Island, and southern Massachusetts). These currents and corresponding water temperatures affect summer recreation in the form of swimming comfort and a cooling sea breeze. Sea breezes are generated by the temperature difference between the cooler water and warmer land. The sea breeze circulation, particularly along New England’s east coast, tends to mitigate frequencies and intensities of thunderstorms in the coastal zone, while bringing relief in the form of mild temperatures in the peak summer heat. In winter, coastal waters remain warm relative to land areas, thereby influencing snow-rain boundaries, which are difficult for forecasters to predict. Third, since New England falls primarily in the zone of the westerlies, the area is dominated by drier continental airflow from various areas across North America, rather than having a prevailing flow from off of the Atlantic Ocean. So, despite the coastal orientation of New England, it does not have a maritime climate like those found on the west coast of the United States. Fourth, New England has mountainous topography which also influences weather patterns. Mountains can enhance precipitation on the windward side, and create drier conditions on the downwind slopes, known as the "rainshadow" effect. Increases in elevation also lead to cooler air temperatures.
Figure 2.1 also depicts air-mass characteristics of New England, based on source regions. As noted, the prevailing wind across most of New England has a westerly component, while southeast winds are least common region-wide. However, winds can, and do, come from all directions on the compass. North and northwest winds deliver to New England cold and dry air from Canada. Moving counter-clockwise, westerly winds transport Canadian air to the region, but the air is generally modified (warmed slightly) as a result of passing over the Great Lakes. Southwesterly winds are very common in New England, but are highly variable in character. These winds can be generated by a high pressure area in the mid-Atlantic states, in which the air is Canadian in origin, but has been modified from the long trajectory over the American Midwest. In this case, the air is generally cool and dry, but can be hot and dry in summer. However, southwest winds are also common after the passage of a warm front, which can carry warm and humid air from the Gulf of Mexico and Caribbean. South and southeast winds are hot or warm and humid, though these winds have low occurrence rates over most of New England, with a notable exception along New England’s south shore. East and northeast winds are cool and humid, as the air takes on the characteristics of the cooler water of the Labrador current and northern Atlantic Ocean. Northeast winds in New England are frequently associated with coastal nor’easters .
As a result of New England’s position relative to the polar front, it’s continental climate type, it’s coastal orientation, and the mountainous topography, the region’s weather is notorious. It is known for its diversity over short distances and changability in a matter of minutes. New England has recorded temperatures up to 107° F and down to -50° F (Ludlum, 1976). The high is hotter than the all-time high temperatures ever recorded in Miami, Florida or Atlanta, Georgia. The low is colder than the record low temperature in Anchorage, Alaska or International Falls, Minnesota - which is commonly the coldest location in the conterminous United States. The region also has rainstorms that rival those in the southeastern United States. As a result, the splendors of New England weather and its bountiful variety were noted by many authors ranging from Robert Frost to Mark Twain. Twain captured the richness of New England weather in his speech at the New England Society’s seventy-first annual dinner in New York:
"Now as to the size of the weather in New England - lengthways, I mean. It is utterly disproportionate to the size of that little country. Half the time, when
it is packed as full as it can stick, you will see New England weather sticking out beyond the edges and projecting around hundreds and hundreds of miles over the neighboring States. She can’t hold a tenth part of her weather"
(Twain, 1935, p. 1110).
Many locations in the United States have the saying " if you don’t like the weather, wait a minute," but nowhere is this more true than in New England. Yet despite the richness of the weather here, and the abundance of severe weather types, little research has concentrated on understanding the dynamic climate of the region.
Extreme Climatic Events in New England History
Of course, what we all want to know is:
How will extreme events impact New England in the future?
The most reliable way to characterize the nature of extreme events and what may happen in the future is to look at the characteristics of these events in the past. By examining such events, we hope to learn how they may have varied in the past, and how they affected the various distinct regions within New England. We also need to examine past magnitudes of these events, their frequencies, and whether trends over time exist for particular types of events, for example, whether the number of exceptionally strong nor’easters increased over the past few centuries. A knowledge of such events may allow us to answer the following general questions:
Did particular types of events occur more frequently in the past then they have in the last few years or even in the 1990s as a whole?What type of trends do we see in the past that may have a bearing on what will happen in the future?
To begin to answer these questions, we have started to examine various sources of data. One is existing instrumental records from meteorological stations across the region. Most of these records span the last century, although a few may cover the last 200 years. To extend our record beyond the last one to two centuries, we are compiling and evaluating daily weather accounts recorded in personal diaries, journals, and almanacs, as well as other types of historical data (e.g., dates of apple harvest and "ice-out" on area lakes) useful in evaluating changes in seasonal conditions over time. These records provide detailed information on not only how these events have varied in the past, but also how they influenced earlier generations of New Englanders.
Following are a few examples of how extreme climatic events (blizzards, ice storms, hurricanes, rainstorms, tornadoes) have varied over the recent past.
Blizzards
Several major snow storms have impacted New England in the 1990s, such as the March 1993 "superstorm" and the large blizzard of 1996, leading to the question of whether we are in a trend of increasing nor’easters, either in number or in magnitude or both. To answer this question as well as to evaluate the record of the number of snow storms in general, the daily number of snowfalls of 1-5 inches (Figure 3.1 ) and of ³ 5 inches (Figure 3.2 ) for Durham, NH (seacoast region) and Hanover, NH (inland site) are plotted beginning with the winter of 1926-1927.
Several interesting results that warrant our continued investigation into possible causes for these patterns can be seen in these records. Beginning with the smaller snowfalls (Figure 3.1 ), the most obvious finding is the greater number of snow events that occur in Hanover compared to Durham. The average number of 1-5 inch snows per year in Hanover over the last 50+ years is almost 16 snows per year compared to about 11 annually in Durham. Such a finding is not unexpected as there are fewer storms that turn to rain or fall completely as rain in Hanover, whereas the warming impact of the ocean changes much solid precipitation to liquid in Durham. Of greater interest is the apparent decreasing trend in the number of snowstorms per year at both sites over this 50+ year record. In general, there were a greater number of years with an average or greater than average number of 1-5 inch snowfalls in the late 1920s to early 1940s than in more recent times. The lowest number of 1-5 inch snows occurs at both sites since about 1980, although there seems to be an increase in the number of storms toward the long-term average in the later part of the 1990s.
Continuing investigation into these records including the use of records from other stations around New Hampshire and New England will lead to a more thorough answer to questions such as:
What is the significance of this general trend to decreasing small snow events in recent years? Is it a function of climate warming that has resulted in a greater number of rain events in the winter over the past two decades compared to the 1920s and 1930s or something else?Is the frequency of these smaller snowstorms in a declining trend or are the trends more variable and fluctuating?
The average number of daily accumulations ³ 5 inches, and thus the greatest number of snowfalls that probably originate from nor’easters, is 3.5 snowfalls per year at both Durham and Hanover. In this case, the greater proximity of Durham to the coast actually results in an equal number of larger snows in the seacoast region of New Hampshire compared to further inland. This scenario reflects the tremendous importance of the track of coastal storms on New Hampshire and New England snowfall totals. A greater number of storms close to the coast will bring a higher number of ³ 5 inch snows to the Hanover area and less to Durham because snow often will change to rain along the coast. If the main storm track is more frequently found farther offshore, there will be a greater number of ³ 5 inch snowfalls in Durham and less in Hanover, since Hanover is farther from the center of such storms. We discuss the long-term trend in these larger snowfalls below. As for the total number of snowfall days, we conclude that there are a greater number of total snowfall events further inland in New Hampshire, but there appears to be an equal number of large storms per year across the region. Continued investigations may further support these initial findings or we may find that there are different trends along the New England coast as a function of latitude.
The long-term trend in the number of larger storms appears to be more variable than that of the general decline in 1-5 inch snowfalls over the 50+ years of record. At both sites (Figure 3.2 ) the greatest number of larger accumulations consistently occurred from roughly the mid-1950s to the late 1970s/early 1980s. The period with the greatest number of large storms per year is the decade from the late 1960s to the late 1970s. There are other years with an abundant number of moderate to larger blizzards such as in the 1930s and 1940s and again in the early 1990s, but they do not occur as frequently as they did in the mid-1950s to late 1970s. Given these initial findings, we ask:
Is there a discernible cyclicity in the number of larger snowfalls across New Hampshire and New England?
To answer this question more completely, it will be necessary to evaluate other snowfall records from around the region, especially at coastal sites such as Boston and Portland, for comparison with other inland sites. Information gathered from as many sites as possible will help us generate and then answer other questions such as:
How has the spatial variability in the number and magnitude of nor’easters changed over time?
Ice Storms
The January 1998 ice storm clearly was a major event in New England history (Figure 3.3 ), but how does it stand up to other ice storms of the past?
Compilations by Ludlum (1976) show that there have been several major ice storms in various parts of New England over the past two centuries. Perhaps the greatest of these was the 26-29 November 1921 storm. Seventy-five hours of rain, freezing rain, sleet and snow fell over central and eastern Massachusetts producing slightly over 4 inches of mixed precipitation in Worcester. Ice was 2 inches thick on many power lines and over 100,000 trees were damaged or destroyed. More recently, a 36-hour period of mixed precipitation and freezing rain in December of 1973 produced total precipitation amounts between 1 and 3 inches in parts of Connecticut. Almost one third of the state was without power and tree damage was estimated to be greater than the 1938 hurricane. Other storms throughout New England in the early 1900s and late 1800s are known to have produced large amounts of mixed precipitation, such as the 7 inches of sleet and ice in northwest Connecticut in February 1898. Although past ice storms may have produced local damage similar to the ice storm of 1998, they pale in comparison to the spatial extent of the damage from the 1998 storm. In addition to the extensive damage in New Hampshire shown in Figure 3.3 , severe damage also occurred in Maine, Vermont, upstate New York and southern Quebec. Because the distribution of damage from past ice storms is not easily compiled, identifying any trends in the number and severity of ice storms over time warrants our continued investigation of this type of climatic event. Surely New England will feel the effects of future storms as we become more susceptible to their widespread impact with increasing population, and modern reliance on electricity, automobile travel, and communication.
Hurricanes
Hurricanes and tropical storms are often classified as the "greatest storms on earth." Although wind speeds in the most powerful hurricanes are not as intense as the most powerful tornadoes, hurricanes encompass a much larger area and can produce damage not only from high winds, but also from storm surge and heavy rainfall. Vast regions can feel the effects of these storms, even locations at great distance from a storm center can be affected because of the wave energy and rainfall that is generated.
Surprisingly, the year with the highest number of storms making landfall in the region was 1888 with three (figure 3.4 ). No other year since has experienced this many tropical storms and hurricanes. There is evidence of temporal clustering of events. For example, during a five-year period from 1896 through 1900, each year experienced one storm event; for the following 11 straight years, 1905-1915, New England had no landfalling storms. The three-year period 1959-1961 had five events, as did 1971-1973.
New England hurricanes generally originate near the Cape Verde Islands or near Bermuda. Their paths exhibit very little curvature while taking a northerly path towards the New England coast (Vega and Binkley, 1994). New England-bound tropical storm systems can maintain much of their intensity as a result of their trajectory over the warm Gulf Stream current, which produces warm sea surface temperatures along the East Coast all the way to the shores of Long Island, Rhode Island, and the south shore of Cape Cod. As a result, southern New England is most vulnerable to hurricane landfall, with Cape Cod having the highest average frequency of hurricane force winds, averaging one occurrence every 14 years. Most of Rhode Island and Connecticut average one occurrence every 17 years, and Maine experiences winds of hurricane strength about once every 20 to 25 years (Simpson and Riehl, 1981). Direct landfall of hurricanes has extremely low probabilities along the eastern Massachusetts and New Hampshire coastline, although these areas are affected by hurricanes making landfall elsewhere in the region.
There are many years on record with no landfalling hurricanes, but near misses are prevalent; (e.g., 1937 had five storms pass near New England) with eventual landfall in the Maritimes of Canada. More recently, in 1996, Hurricanes Edouard and Hortense gave New Englanders a scare as they churned up the East Coast, before veering away from the area. In such instances, the storms can generate enough wave energy, and sometimes storm surge, that coastal erosion and flooding can cause serious damage. High winds can also be generated in the coastal zone in these cases. Also, a number of storms have made landfall much farther south, e.g., along the Gulf of Mexico coast or along the east coast in the southern United States, but are steered to New England over land. For example in 1979, Hurricane David made landfall in South Carolina, then passed through the mid-Atlantic states to New York and finally passed through Vermont, New Hampshire, and Maine. That same year, Hurricane Frederick made landfall near Mobile, Alabama, and over land made it to northern Vermont and Maine. Such storms arrive here in a weakened condition or as storm remnants, but their impacts can be significant. For example, Hurricane Bertha in 1996 made landfall in North Carolina and traveled inland to New England where it still was able to produce very heavy rainfall region wide.
Despite their rare appearances, tropical storms and hurricanes tend to have a large impact in the region because of the high population density found in the New England coastal zone. Perhaps the most notorious New England hurricane was the Hurricane of 1938, which was a Category 3 hurricane, with winds speeds between
111 and 130 mph. This storm made landfall over Long Island, New York, and western Connecticut, and then took a northerly path through western Massachusetts and western Vermont, with a forward velocity of over 60 mph (Ludlum, 1976). It was the 21st most powerful storm to strike the United States in the 20th century, yet was the fourth deadliest in the United States, with 600 deaths attributed directly to it and its aftermath. Part of the explanation for the high death toll stems from the high population base that was affected; in addition, there was little notice that the storm was even coming. Storm surge was up to seventeen feet in some locations in Rhode Island and Massachusetts, with reports of waves between 30 and 40 feet high (Ludlum, 1976). Over $4 billion (adjusted for inflation) in damages were incurred, which ranks as the eighth most costly storm in United States history.
Surprisingly, the Hurricane of 1938 was only the second most powerful to make landfall in New England (Table 1). Hurricane Gloria in 1985 was the most powerful to make landfall here, packing winds over 140 mph. In contrast to 1938, however, emergency preparedness was much improved, and Hurricane Gloria did not take the same toll in human lives, nor in property damage. Interestingly, the fourth and fifth most powerful storms to strike New England occurred just 11 days apart in 1954.
Could it be possible that tropical storms and hurricanes are becoming less intense and less frequent in New England?
Given the dates presented in Table 1 (in addition to the time series in Figure 3.4 ), there is no suggestion that New England hurricanes and tropical storms are now getting more intense or frequent, which is in general agreement with the results of Henderson-Sellers et al. (1998) for the North Atlantic and North Pacific basins. In fact, four of the top five events this century occurred prior to 1955.
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Table 1. Five most Intense New England Hurricanes, 1900-97. |
||
|
Hurricane |
|
Pressure in Millibars |
|
Gloria |
|
942 |
|
Number 4-1938 |
|
946 |
|
Number 7-1944 |
|
947 |
|
Edna |
|
954 |
|
Carol |
|
960 |
|
Source is the National Hurricane Center. Since accurate wind speed data are lacking for many hurricanes in the earlier decades examined, the central barometric pressure of the hurricanes are posted as an index for storm strength, with lower pressure relating to a stronger storm. |
||
Rainstorms
New England can experience heavy rainfall from three sources: hurricanes/tropical storms and their remnants, nor’easters or other synoptic-scale mid-latitude cyclones, and localized storms that are generated by free-convection , particularly in summer. Summertime free-convection can produce very extreme rainfall, but is typically limited in area and generally of lesser magnitude than those rainstorms produced by larger-scale features. Therefore, this discussion focuses on the more regional heavy rains produced by the two former mechanisms.
Table 2 displays the largest precipitation events recorded in New England over the past 50 years. The largest single-day precipitation event recorded in New England was 18.15 inches at Westfield, Massachusetts, produced by Hurricane Diane in late August 1955. In all, this single event produced 19.75 inches of rainfall at Westfield over three days (18-20 August 1955), which is the single largest rainfall event in New England (Keim, 1998). One-day rainfall totals from this event were in excess of 10 inches at numerous sites in Massachusetts and Connecticut. It was particularly damaging because the storm followed the heavy rains produced by Hurricane Connie in southern New England on 12-13 August. As a result of these two storms, the month of August 1955 went into the record books as one of the all-time record months for total precipitation, with values reaching over 25 inches for parts of Massachusetts and Connecticut (Figure 3.5 ).
The second greatest singe-day rainfall event occurred in late October of 1996 and is detailed by Keim (1998). This event, produced by a "continental nor’easter," generated the heaviest rainfall values along the east coast of New England from Boston, Massachusetts, to Portland, Maine (Figure 3.6 ). From this event, Camp Ellis and Gorham, Maine, recorded storm rainfall totals over three days of 19.2 and 19.0 inches, respectively. Also, Maine and New Hampshire set all-time records for one-day rainfall events during this storm. Analysis of rainfall extremes in the region revealed that the event was in gross excess of a 100-year storm event between Boston and Portland, and at some locations in Maine, it was close to a 500-year storm event. In other words, a storm of this magnitude or greater could be expected to occur only once every 500 years, on the average, or that any single year has a 1/5th of 1 percent chance of experiencing a storm like this. Impacts included river-basin flooding, loss of potable water supplies, and road and bridge damage.
Five of the eight storms listed in Table 2 occurred in the months from August to October, suggesting that these events are usually tropical, in the form of a hurricane or tropical storm. However, some of the most powerful nor’easters can also occur in October (Dolan and Davis, 1992), and these weather systems are generators of heavy rainfall. Of these eight events, all but the storms on 6 June 1982, 31 December 1948, and 16 October 1955 had some tropical component. Even the continental nor’easter on 21 October 1996 had some of its moisture contributed by Hurricane Lili, located in the Atlantic at the time. Interaction between tropical storms/hurricanes and mid-latitude storm systems is not unprecedented in New England; e.g., the Vermont flood of 1927 was produced under similar circumstances. Though not included in Table 2, this event produced 9.65 inches of rain at Somerset, Vermont, with estimates of 15 inches at higher elevations nearby (Ludlum, 1976).
Based on Table 2, there is no suggestion that the heaviest of rainfall events are increasing as a result of global warming, since half of these events occurred in the first 8 years (1948-1955) under examination. However, the 1990s have experienced some unusual rain and flood events; e.g., Portsmouth, New Hampshire had two events in the past three years, one of which exceeded a 100-year event (October 1996) and the other exceeded a 50-year event (June 1998). These results illustrate the difficulty in trying to understand what is happening based on a fifty-year record, and the urgency of creating a much longer one.
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Table 2. Largest 1-day Precipitation Events Recorded in New England, 1948-97. |
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|
Location |
|
Rainfall (in.) |
|
Westfield, MA |
|
18.15 |
|
Portland, ME |
|
11.71 |
|
Cockaponset, RI |
|
10.47 |
|
Torrington, CT |
|
8.91 |
|
Middleton, MA |
|
8.64 |
|
Woods Hole, MA |
|
8.55 |
|
Norfolk, CT |
|
8.20 |
|
Brunswick, ME |
|
8.05 |
|
Source is the New Hampshire State Climate Office, University of New Hampshire. |
||
Tornadoes
Tornadoes are arguably the most violent storms on earth. They can have wind speeds well over 250 mph, with documented examples of trucks and railroad coaches being lifted off of the ground and dropped hundreds of feet away (Lutgens and Tarbuck, 1998). Similarly, large trees are easily uprooted, and houses present little resistance to the most powerful tornadoes. Fortunately, tornado outbreaks are relatively rare in New England when compared to frequencies on the Great Plains of the United States, e.g., Texas, Oklahoma, Kansas, and Nebraska. In fact, New England gets the fewest tornadoes of any region east of the Rocky Mountains. However, despite the low occurrence rate of these violent storms, there are documented cases in all corners of New England ranging from the Allagash Valley, Maine, in the northeast, to Nantucket Island in the southeast, Greenwich, Connecticut, in the southwest, and St. Albans, Vermont, in the northwest (Ludlum, 1976). The average New England tornado occurs in summer, in the late afternoon, and travels from southwest to northeast at a speed between 25 and 40 mph.
In New England, Massachusetts has the highest number of documented tornadoes (and obviously the highest annual average) and Rhode Island has the smallest number of documented events (Table 3). The area most affected by tornadoes lies just to the east of the Berkshires in north-central Massachusetts (Leathers, 1994). Maine, New Hampshire and Connecticut are close in number in their statewide tornado occurrence rates, averaging between 1.4 and 1.8 per year. However, tornado frequencies in New England pale in comparison to the Great Plains, which receive approximately ten times as many tornadoes as New England. For example, compare these averages to states like Texas and Oklahoma which reported 5860 (125 per year) and 2420 (51 per year) tornadoes, respectively, over this same time period.
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Table 3. Number of Documented Tornadoes for each N.E. State, 1950-96. |
||
|
State |
|
Average Per Year |
|
Massachusetts |
|
2.9 |
|
Maine |
|
1.8 |
|
New Hampshire |
|
1.6 |
|
Connecticut |
|
1.4 |
|
Vermont |
|
0.7 |
|
Rhode Island |
|
0.2 |
|
Source is the National Severe Storms Laboratory. |
||
New England gets far fewer tornadoes than most other states because of its location. It is situated far enough north that the jet stream orientation for much of the year is located south of New England and relatively cool temperatures prevail in the region. The cooler temperatures serve to stabilize the atmosphere, which suppresses opportunities for the development of tornadoes. In summer (July and August, in particular), the jet stream moves farther north, bringing warmer conditions and greater instability to New England. This instability results in greater thunderstorm activity and the potential for tornado development. However, the cold water off the east coast of New England in summer lessens the intensity of thunderstorms, which are the purveyors of tornado outbreaks. As a result, tornadoes are rare within about 15 miles of the coast. Although the values in Table 3 are not adjusted for area, the relatively small number of events in Rhode Island is partly driven by its coastal location, even though the water temperatures are warmer in this region than along the eastern coastal zone of New England.
By far, the worst to strike in New England was the Worcester tornado of 9 June 1953 (Table 4). The Worcester tornado touched down at Petersham, Massachusetts, and took a path east-southeastward to Southboro, Massachusetts, covering 46 miles and lasting an hour and twenty minutes. Nested within the same storm system, two other tornadoes were spawned that day in Exeter, New Hampshire, and Sutton, Massachusetts. Clearly this was one of the worst tornado days in New England history, with 90 deaths from the one tornado alone (mostly in Worcester) and 94 from the three tornadoes combined (Ludlum, 1976). The second worst tornado (in New York and Massachusetts) led to 8 deaths. There have only been 17 tornadoes between 1880 and 1995 that are known to have taken lives in New England. Even weaker tornadoes can take lives as was the case on July 4, 1898, in Hampton, New Hampshire.
|
Table 4. Most Deadly New England Tornadoes, 1880-95. |
|||||
|
County, State |
|
|
|
|
Killed |
|
Worcester, MA |
|
|
|
|
90 |
|
Essex, MA |
|
|
|
|
8 |
|
Columbia, NY- |
|
|
|
|
4 |
|
Hampton, NH |
|
|
|
|
3 |
|
Hartford, CT- |
|
|
|
|
3 |
|
Berkshire, MA |
|
|
|
|
3 |
|
Sources are Grazulius (1991) and The Tornado Project, St Johnsbury, Vermont found on the world wide web at http://www.tornadoproject.com/. |
|||||
Figure 3.7 displays an annual time series of tornado frequencies in New England. This series includes all tornadoes of F1 strength (on the Fujita scale ) or greater, which corresponds to wind speeds of 73 mph or more, but does not include F0 tornadoes. As shown, there were few powerful tornadoes near the turn of the 20th century, with some clustering of events beginning near 1950 and continuing into the early 1970s. The lower frequency in the early portion of the time series could simply be the result of lower population densities, lower reporting rates, and poor communication. The biggest year on record was 1972, which included a total of four events. Frequencies appear to have declined in the 1980s and 1990s, which is a time when global temperatures were largely above normal. It is probable that the recent decline is weather-related and not a societal artifact, as is likely in the earlier portion of the time series. This decline over the past two decades, however, is in contrast to the rest of the United States, where the 1990s have seen unprecedented numbers of reported tornadoes.
Value of Written Records
One of the most famous single events to influence New England climate, and an event that has been well documented in the annals of New England climate, was the 1815 volcanic eruption of Tambora, Indonesia, the largest known historical eruption in the world. Although situated almost directly on the equator and on the other side of the world, this extremely large eruption influenced global climate, with an especially severe impact on New England. The large amount of sulfuric acid eventually produced in the stratosphere by sulfur-rich gases released during the eruption blocked out solar radiation, resulting in a cooling of Earth’s surface for several years after the eruption. This process led to the famous "Year Without a Summer" of 1816. Many diaries and newspaper accounts from around New England make particular note of that cold summer including accumulating snow in early June in northern New England with flurries as far south as Massachusetts and Connecticut and exceptionally cold nights in July and early August that resulted in isolated pockets of frost (Ludlum, 1976). These highly unusual summer phenomena led to great crop losses (Stommel and Stommel, 1983).
Certainly the impact of the Tambora eruption was phenomenal in the annals of New England climate, but this is not to say that only an eruption of that size can have an impact on climate in this area. An evaluation of annual temperature and especially summer temperatures (June, July, August) in Durham, NH, over almost the last 100 years shows that some of the coolest summers follow major volcanic eruptions (Figure 3.8 ). Individuals whose livelihood is dependent on summer climatic conditions should be well aware of the potential for a very cool summer following the next major volcanic eruption.
However, it is also important to realize that volcanic eruptions are just one of the many factors that force and control New England’s climate. In the record of Durham annual and summer temperatures (Figure 3.8 ), there are other summers that are below the long-term trends. Moreover, it is clear that there is a periodicity in temperature trends in Durham such as the overall warmer conditions of the 1950s followed by the cooler 1960s. Our investigations are focusing on defining any long-term trends and the periodicity of these shorter-term fluctuations in temperature, both of which may be related to other climate-forcing factors such as variability in Earth’s orbital cycles, solar radiation, El Niño events, and greenhouse gases. Considering the tremendous impact and public awareness of the 1997-1998 El Niño event, we are evaluating the impact of other El Niño events (of varying intensity) during this past century to quantify the range of climatic impact from El Niño in New England. We need to "single-out" the impact of each of these forcing factors, including the volcanic forcing component, on New England’s climate to better inform the general public on what may be expected in the future.
In contrast to the frequently referenced cold summer of 1816 throughout New England, a series of snow storms between 17 and 24 February 1893 has not been given the recognition it may deserve as one of New England's greatest snow events. Most compilations of blizzards, and thus nor'easters , in New England, highlight the storms of 1717 and 1888 as among the greatest in historical time (e.g., Ludlum, 1976; Kocin and Uccellini, 1990). For instance, a series of four storms between 27 February and 7 March 1717 dumped upwards of 35-45 inches across southern New England, while the 11-14 March 1888 blizzard dumped up to 50 inches of snow in some parts of central Connecticut and 30-36 inches in southern New Hampshire (Ludlum, 1976). The large amount of snow from the 1888 blizzard resulted from a "stalled" low pressure system off of Block Island, Rhode Island, and thus from a single storm.
However, the diary of George H. Lang of Rye, NH, (diary dates 1871-1901) makes particular note of the series of snow storms between 17 and 24 February 1893. Five separate storms in quick succession resulted in the greatest snowfall accumulation that he had ever seen as he "shoveled out whole length of the district." He was 65 at the time of these storms. Lang notes that "a rough and tough old East snow storm set in" on 12 March 1888, and that it was "one of the rough ones for years, " but Lang makes no note of tremendous snowfalls in Rye like he did for the 1893 storms. Similarly, the diary of Seth Dame, Nottingham, NH, makes note of a blizzard on 20 February 1893 and a second blizzard on 22 February 1893. Both of these storms dropped about a foot of snow, and together with two 3+ inch accumulations on the days before and after these blizzards, a total of over 30 inches fell between 17 and 24 February 1893 in Nottingham. Dame also noted that a "severe snowstorm" occurred on 12 March 1888, but he makes no additional comments which would indicate that it was comparable to the 1893 snows.
Surprisingly, the only note in the compilation of extreme weather events by Ludlum (1976) that references an exceptionally large snowfall in late February of 1893 is that for Monroe in the Berkshires of western Massachusetts. That town recorded 53 inches over a six day period ending on 25 February which contributed to the snowiest February as well as the snowiest winter (1892-1893) on record in Monroe, at least prior to Ludlum’s compilation in 1976. Thus, the amount of snowfall in western Massachusetts to eastern New Hampshire between 19 and 25 February 1893 may have been equivalent to, if not more than, that of the great blizzard of 1888. In addition, both the Lang and Dame diaries note a severe storm on 13 February 1893 that produced a foot of snow in Nottingham. Southeastern New Hampshire was covered by over 40 inches of snow between 13 and 24 February 1893, amounts similar to that for the 1717 great snow.
The diaries of George H. Lang and Seth Dame and their accounts of the tremendous snows of February 1893 in the seacoast of New Hampshire as compared to those for the "Blizzard of ‘88" highlight the great potential for extreme events in New England climate. Our initial investigations into the wealth of information available in written records, such as the accounts of the tremendous snows of February 1893, also show the limited number of compilations of past climatic events now in existence. A thorough understanding of variability in the system requires the compilation of climatic records from across the area. No single record will provide the details needed to reconstruct what happened in the past and ultimately postulate what may happen in the future. This is particularly true for the extreme events discussed as well as other types of extreme events like hot spells, cold waves, floods and droughts. Everybody is well aware of the problems of predicting snowfall totals across New England with the approach of a coastal storm. Conditions can vary from no precipitation to rain to mixed precipitation to almost two feet of snow over a zone of less than 50-60 miles. It is important to use all available information to isolate trends in these extreme events and to understand the potential impact they had and could have on New England society both as a whole and within the various parts of the region.
Air Quality in New England
There currently exist several air quality monitoring programs aimed at developing quantitative measures of air quality through the analysis of a variety of chemical species in the atmosphere. Among these are the National Atmospheric Deposition Program (NADP) , which has been monitoring the acidity and chemical content of precipitation throughout the United States for the past two decades and the Environmental Protection Agency’s - Photochemical Assessment Monitoring Stations (PAMS ), which provide an air quality data base for dealing with ozone and other criteria pollutants . Programs such as these, in combination with several smaller scale research and monitoring projects, provide the basis for monitoring the quality of the air we breathe.
Tracking Air-Masses Affecting New England Using Chemical Tracers
While many atmospheric parameters (such as temperature, sunlight, precipitation, humidity, etc.) influence the composition of air-masses, natural and anthropogenic emissions in the source regions remain one of the most critical for determining the chemical fingerprint of an air-mass. Air chemistry monitoring therefore represents a valuable tool for identifying the source region for various air-masses. To better identify the source regions for air-masses traveling to New England and their influence on the region’s air quality, aerosol and precipitation chemistry is currently being investigated at the Mount Washington Observatory and on the New Hampshire Seacoast at Odiorne Point, Rye by the Climate Change Research Center. Below we provide several examples of the intimate link between air-mass source regions and air chemistry in New England.
Aerosol Chemistry on New Hampshire’s Seacoast
The New Hampshire seacoast lies downwind of the major metropolitan centers and transportation corridors in New England, and therefore provides a suitable site to investigate the impact of both local and distant sources of pollution. At Odiorne Point, aerosols are collected daily on Teflon filters and analyzed for their soluble major ion chemistry (sodium, ammonium, potassium, magnesium, calcium, chloride, nitrate and sulfate). Aerosols with distinct chemical compositions originate from different source regions and can therefore be used to "fingerprint" different air-masses. Daily weather maps made available by the National Oceanic and Atmospheric Administration (NOAA) are also analyzed to determine air flow patterns and thereby identify potential source regions. Through this combined approach of investigating physical and chemical climate, air chemistry data can be used to determine the source regions of various air-masses.
Figure 4.1 shows some of our preliminary results from aerosol samples collected over two months during the spring of 1998. Marine air-masses (those coming from the east) show high levels of sea salt (composed primarily of sodium and chloride); air-masses from the eastern seaboard south of New England show high levels of acidic species, indicative of anthropogenic emissions from the burning of fossil fuels in the mid-Atlantic states; and air-masses from Canada show very low sea-salt, indicative of their continental origin, but high sulfate, perhaps originating from the smelting of sulfur rich ores in the Sudbury region of Ontario (Clark, 1980). Air-masses from the northwest (i.e., those originating in Canada) also show high levels of ammonium, likely reflecting agricultural sources from rural areas to the northwest of New Hampshire’s seacoast (Lefer, 1997).
Rime-Ice Chemistry on Mount Washington
In February of 1998, rime-ice samples were collected at the summit of Mount Washington to investigate how air-masses from different geographic regions affect the precipitation chemistry, and hence air quality, over Mount Washington. The summit of Mount Washington was chosen as a study site because it is one of the most remote locations in New England and is situated at the intersection of three of North America’s major storm tracks. As such, the summit of Mount Washington is an ideal location to study how emissions emanating from other regions of the country affect the chemical climate of northern New England.
The results from the Mount Washington study are complementary to those from Odiorne Point. There was a distinct change in concentration of sea-salt, nitrate, non sea-salt (nss) sulfate, and ammonium in rime-ice at Mount Washington on 21 February 1998 (Figure 4.2 ). The change in rime-ice chemistry is due to a shift in air-mass source region from a southwest trajectory out of the Ohio River Valley during the morning to a west-northwest trajectory out of Ontario, Canada in the afternoon. Rime-ice from the southwesterly derived air-mass contained elevated concentrations of nitrate and nss sulfate likely reflecting emissions from coal- and oil-burning power plants and mobile sources (e.g., cars and trucks) in the Ohio River Valley. The shift to a west-northwest air-mass trajectory was coincident with a decrease in the concentration of nitrate and an increase in concentration of nss sulfate, perhaps reflecting anthropogenic sources in the Great Lakes industrial region and/or Sudbury, Ontario. This "Canadian" air-mass also shows higher levels of ammonium, consistent with agricultural sources to the northwest of Mount Washington.
Continued monitoring of a wide variety of air quality parameters on the seacoast, at Mount Washington, and at several other sites throughout the state will allow us to develop a much better understanding of the relationship between air quality in New England and the transport of pollution from upwind sources into the region.
Acid rain and the Environmental Impact of the Clean Air Act
Precipitation chemistry records derived from a Greenland ice core (Figure 1.3, Mayewski et al., 1990) reveal a dramatic increase in the concentrations of sulfate and nitrate following the industrial revolution (approximately 1900 AD), as mentioned in Chapter One. The Greenland ice core record also shows a leveling off of sulfate and nitrate concentrations after 1970 when the National Ambient Air Quality Standards (NAAQS) were established as part of the Clean Air Act . The 1970 amendments to the Federal Clean Air Act were developed to protect the public’s health and welfare by controlling air pollution at its source through the establishment of primary and secondary NAAQS. Since 1970 several amendments have been made establishing stricter primary and secondary NAAQS as a result of a better understanding of the impact that air pollutants have on human health and the environment.
Acid rain is caused primarily by the emission of sulfur dioxide (SO2) and nitrogen oxides (NOx) from the combustion of fossil fuels that we use to heat our homes, power our cars, generate electricity, and run our factories. Here in the Northeast, this phenomenon has caused lakes and stream to become unsuitable for many fish (Baker and Schofield, 1985; Park, 1987). Acid rain has been known to leach heavy metals such as mercury from rocks, thereby causing contamination of water supplies and introducing human health risks (Brakke et al., 1988). Acid rain can also alter soil chemistry in agricultural and forested lands and causes significant damage to human made structures, especially those consisting of limestone and marble. In addition to contributing to acid rain, sulfate aerosols also play a significant role in Earth’s radiation balance. The increase in sulfate aerosol in the troposphere adjacent to industrial regions of the globe over the past century has in fact served to cool climate on a regional scale (Charlson et al., 1992; Mayewski et al., 1993, IPCC, 1995).
How has the Clean Air Act affected the acid rain problem in the northeast?
Aerosol chemistry samples from Whiteface Mountain in upstate New York show a strong correlation between the decrease in SO2 emissions in the mid-western states since 1970 and the decrease in average sulfate concentrations in the Northeast (Husain et al., 1998). The deposition of sulfate in precipitation in northern New England measured at four locations has decreased on the order of 30% since the early 1980s ( Figure 4.3a ). In addition, the longest precipitation chemistry record in New England, measured at Hubbard Brook in northern New Hampshire, shows that the average pH of precipitation has increased since 1970 from approximately 4.1 to 4.3 standard pH units (Figure 4.4 ), indicating that the acidity of precipitation is slowly decreasing. The same cannot be said for the deposition of nitrate, which has shown no significant change since the early 1980s (Figure 4.3b ).
The decrease in sulfate deposition and precipitation acidity can be directly linked to the reduction in SO2 emissions as a result of the Clean Air Act. In fact, annual SO2 emissions from anthropogenic sources in the U.S. have decreased from 28.3 million metric tons in 1970 to 17.4 million metric tons in 1996 (Figure 4.5 ). This is due primarily to a reduction in sulfur emissions from electric utilities, which are responsible for approximately two-thirds of the nation’s sulfur emissions. At the same time, nitrogen oxides emission rates have increased from 19.7 million metric tons in 1970 to 21.3 million metric tons in 1996. This increase can largely be related to the more than doubling of vehicle miles traveled over the past three decades. (U.S.EPA, 1977). Motor vehicles currently account for approximately 30% of all nitrogen oxides emissions.
Clearly, the Clean Air Act Amendments have been successful in reducing sulfur oxides emission rates and sulfate deposition via precipitation. On the other hand, nitrogen oxides emission rates have continued to increase, albeit slowly, and wet deposition of nitrate has remained relatively constant. Amendments to the Clean Air Act that were designed to reduce emissions of criteria pollutants further were passed in 1990 and were phased in starting in 1995. Ongoing air quality monitoring and research programs will evaluate the effect of the 1995 amendments on air quality in coming years.
Ozone in New England
Ozone is a very important chemical in our atmosphere. It is found in the troposphere (near the earth’s surface, where our weather occurs) as well as in the stratosphere (above the troposphere). Ozone in the stratosphere protects us from ultraviolet radiation. Scientists are concerned about the depletion of this ozone layer, particularly the ozone "hole" over Antarctica, as well as the more recent depletion in northern latitudes. Ozone in the troposphere affects us very differently. Tropospheric ozone, a component of urban smog, causes health problems for humans and ecosystems. In high concentrations for periods of a few hours, ozone can damage lung tissue, reduce lung function, irritate eyes, and is also harmful to plants.
Tropospheric ozone is a pollutant which affects large geographical areas when weather conditions are favorable for its formation. Ozone at ground-level is a secondary pollutant which forms in the atmosphere as a by-product of chemical reactions that take place between other chemical compounds (i.e. ozone precursors) emitted from automobiles, diesel trucks and industrial sources. Specifically, these ozone precursors are volatile organic compounds (VOCs) and oxides of nitrogen (NOx). These compounds react together when exposed to strong ultraviolet radiation from the sun during hot summer weather.
Ozone, NOx , and VOCs are currently monitored by State Environmental Agencies. Several stations have been established in New England since several cities in the region (including the Dover-Portsmouth-Rochester region) are designated as "serious non-attainment zones" for ozone by the EPA. Very high ozone levels occur in the seacoast regions of Maine, New Hampshire, and Massachusetts during the summer due to a combination of factors. These areas are densely populated and produce an abundance of pollution themselves. The area also tends to be sunny in spring and summer because of the sea breeze effect, which inhibits cloud formation. However, ozone levels tend to rise to their highest and most unhealthy levels when pollutants are transported into New England from regions to the southwest along what is known as the ozone transport corridor.
In 1997, the EPA changed its criteria for unhealthy ozone levels. Instead of hourly ozone levels exceeding 120 parts per billion (ppb), an 8-hour average of over 80 ppb is now considered an "exceedance". Some individuals may be affected by short periods of very high ozone, but it is more harmful for most people and for plants to be exposed for longer periods of time, even at a lower level. This change in standards resulted in more events being classified as very unhealthy (Figure 4.6 ).
The high number of unhealthy ozone days in 1988 is remarkable. This is primarily attributed to a circulation pattern which brought several periods of hot sunny weather to the Northeast. This circulation pattern was linked to a phenomenon in the southern Pacific ocean called La Niña , which often follows a prolonged El Niño event. Interestingly, climate events halfway around the world have a significant effect on our region’s air quality.
On average, southern New Hampshire and coastal Maine experience 3 to 5 days per year of very unhealthy ozone levels, with some years (e.g., 1988) that are considerably worse. However, high ozone levels are not restricted to these areas. In fact, very unhealthy levels of ozone have also been measured by the Appalachian Mountain Club (AMC) at the summit of Mount Washington.
What is the anatomy of a high ozone event in New England?
Below, we provide 3 examples of ozone events in New Hampshire to illustrate what we know and what we do not concerning the causes of high ozone events in the region.
1. High Ozone along the East Coast, June 28-July 1, 1997: On 28 June a high pressure center to the west of New England yielded sunny skies (Figure 4.7a ). Pollutants from the seacoast reacted with sunlight to form ozone. However, by 1 July, ozone levels increased by an additional 50%.
Why this increase?
As the high pressure system moved eastwards, the prevailing winds shifted from a northwest to a southwest direction, transporting pollutants and already-formed ozone from other industrial areas to the southwest and along the east coast of the U.S. (Figure 4.7b ), adding to already high ozone levels. The influence of ozone transported into coastal New Hampshire and Maine is clearly illustrated in Figure 4.8 . Ozone and its precursors move with the weather systems and ozone formed as a result of New York or Boston emissions can impact populations in New Hampshire and Maine on a hot summer day. The highest ozone levels of the day typically occurs late in the afternoon at monitoring stations most susceptible to long range transport. Coastal ozone monitors in New Hampshire and Maine usually record the highest ozone concentrations as a result of transport over the open ocean from the big cities to the south. Wind direction on a hot summer afternoon will determine if ground-level ozone is going to be a problem on a particular day. In addition, peak values for ozone rise steadily from 28 June to 1 July, as more polluted air is transported into the region (Figure 4.9 ). Note that the trend in NO2, one chemical compound which contributes to ozone formation, shows a trend which is opposite to that for ozone (i.e., low values during the afternoon when ozone levels are greatest). This illustrates NO2 consumption during the series of reactions that lead to the formation of ozone.
2. High Ozone at Portsmouth and Mt. Washington, 11 July 1988: This was a period of very high ozone on the seacoast as well as on the summit of Mount Washington (figure 4.10 ). As usual, the seacoast levels drop dramatically at night as tropospheric ozone was effectively removed from the atmosphere close to the ground and because it is not produced after the sun goes down. Atop Mount Washington, though, the readings remained very high, actually peaking in the early morning on the 11th, and not dropping below 70 ppb for three straight days. The White Mountain region is not a major pollutant source, and therefore the ozone was probably carried in on westerly winds. The lack of a diurnal variation is explained by the fact that there is very little ground surface at the summit of Mt. Washington, so ozone is not readily removed from the atmosphere. Note that ozone levels at the base of the mountain were much lower than at the summit, day and night, even though it is only four miles away. The dense forest environment at the base serves to rapidly remove ozone from the atmosphere.
3. High ozone only on Mount Washington, 4-5 July, 1989: Ozone levels on the summit of Mt. Washington peaked early on 5 July at about 130 ppb, well above normal and healthy levels. However, ozone levels at the base of the mountain and on the seacoast never exceeded 60 ppb. (figure 4.11 )
Why the difference between sites, and why did it peak in the early morning when ozone formation is normally highest in the afternoon?
Perhaps a disturbance in the layer that separates the troposphere from the stratosphere allowed ozone from the stratosphere ("good" ozone, our protective shield) to accumulate for a short period at the summit of Mt. Washington, but was not transported to low elevations such as the base of Mt. Washington or the seacoast. This peak may also represent the long-range transport of ozone from the west or southwest at elevations of 5000 - 6000 feet (i.e., the summit elevation of Mount Washington), which would not influence ozone concentration on the seacoast. Future monitoring of a variety of both gas phase and aerosol chemistry will provide the data necessary to answer these and other important scientific questions regarding air quality in New England.
Why continue to investigate air quality in New England?
Clearly, our general understanding of chemical climate in New England over the past two decades improved substantially - especially with respect to acid rain and ozone. However, many of the specifics regarding air quality issues remain poorly understood. In conjunction with ongoing air quality monitoring programs in the region, we plan to develop a detailed air quality/air-mass trajectory data base in order to address several specific scientific questions, including:
How much of the poor air quality that we suffer from in New England is the result of pollution produced locally verses pollution that is transported into the region from upwind sources (e.g., mid-west or mid-Atlantic states)? How much does this change over days, weeks, months, and seasons?How will changes in the strength of these local and upwind sources (as mandated by the Clean Air Act) affect air quality in New England over the coming years?
What and where are the specific sources of pollution, and which weather patterns cause the worst air quality in New England?
Are there significant differences between air quality in the mountains and the seacoast regions of New England? Why?
How will the predicted warming of 2.5 o to 4 oC with a doubling of atmospheric carbon dioxide (IPCC, 1995), and the potential changes in precipitation and atmospheric circulation patterns, affect New England’s chemical climate?
How will regional and long traveled pollution aerosol influence the Earth’s radiation budget over New England?
Answers to these and other questions regarding the quality of the air we breathe are being sought through the examination of data collected from existing sites and that proposed at future sites. Results will provide us with the understanding to deal with air quality issues in the future.
New England Climate Research Goals for the Next Decade
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United States Department of Commerce. 1955. Climatological Data for New England: August. National Climatic Data Center: Asheville, North Carolina.
U.S. EPA. 1997. National Air Pollutant Trends, 1900-1996. Office of Air Quality Planning and Standards, Research Triangle Park, NC, EPA-454/R-97-011. (Available on the EPA Web site - see information below.)
Vega, A.J., and Binkley, M.S. 1994. Tropical Cyclone Landfall in the United States 1960-1989. National Weather Digest 19:14-26.
Additional Information on the World Wide Web
http://www.grg.sr.unh.edu/ccrc/
Climate Change Research Center (CCRC) and New England Climate Initiative (NECI) Provides information on CCRC and NECI, as well as a link to the NH State Climatologist; most of the web pages listed below can be accessed from our web page.
http://www.nicl-smo.sr.unh.edu/NICL/
National Ice Core Laboratory
A great starting point for learning more about ice core research. The
recent document written by the U. S. Ice Core Working Group titled
"Ice Core Contributions to Global Change Research" is available from
this site.
Plymouth State College weather center
http://www.mountwashington.org
The Mount Washington Observatory
http://www.state.me.us/dep/air/home.htm
Maine Department of Environmental Protection
http://www.magnet.state.ma.us/dep/bwp/daqc/daqchome.htm
Massachusetts Department of Environmental Protection
http://www.state.nh.us/des/ard/
New Hampshire Department of Environmental Protection
http://www.anr.state.vt.us/dec/air/
Vermont Department of Environmental Protection
All of these state sponsored web pages provide OZONE FORECASTS during the summertime, as well as a wealth of other information regarding air quality issues in the northeast.
Ozone information by phone: MAINE: 800-223-1196; MASS: 800-882-1497;
NH: 800-935-SMOG
http://nadp.sws.uiuc.edu/nadpdata/
National Atmospheric Deposition Program (NADP)
Precipitation chemistry data for the United States is available from
this site.
http://uplink.syr.edu/access/hbef/research/data.html
The Hubbard Brook Ecosystem Study
Data and information from a wide variety of research projects
conducted at the Hubbard Brook Watershed in New Hampshire’s
White Mountains
http://www.epa.gov/oar/emtrends.html/
National Air Pollution Trends Report published by the US Environmental Protection Agency
Air pollution data for the entire United States is available online at this US Environmental Protection Agency site.
http://www.nescaum.org/index.html
Northeast States for Coordinated Air Use Management
An interstate association of air quality control divisions in the Northeast States web page that provides access to air quality data for the entire region.
Chapter 2 - Dr. Barry Keim, New Hampshire State Climatologist and Assistant Professor in the Department of Geography and the Climate Change Research Center in the Institute for the Study of Earth, Oceans and Space.
Chapter 3 - Dr. Gregory A. Zielinski, Research Associate Professor in the Climate Change Research Center in the Institute for the Study of Earth, Oceans and Space and the Department of Earth Sciences. Dr. Barry Keim, see above. Mr. Justin Cox, Iola Hubbard Climate Change Endowment Undergraduate Summer Fellow.
Chapter 4 - Dr. Cameron Wake,
Research Assistant Professor in the Climate Change Research Center in the Institute for the Study of Earth, Oceans and Space and the Department of Earth Sciences. Mr. Kevan Carpenter, Research
Technician, Climate Change Research Center in the Institute for the Study of Earth, Oceans and Space.
Mr. Justin Cox, see above. Mr. Joe Souney, Iola Hubbard Climate Change
Graduate Summer Fellow. Mr. Paul Sanborn, New Hampshire Department of Environmental Services. Mr. Mark Rodgers, Department of Chemistry, University of New Hampshire.
