The Final Post

Minnesota is nestled in the in the path of ancient glaciers and oceans. As a result of this history, lakes and valleys predominate across the landscape. The humidity of the region in a major factor in the mesoscale climatic controls that shape the weather here. The geography of Minnesota has been dramatically altered by glacial times and the most notable result is the prevalence of the states ability to retain precipitation. With a high water table and abundant pools, the high humidity of the region creates bitterly cold winters and unbearably warm summers. Additionally, some parts of northern Minnesota are even influenced by the stabilizing properties of large bodies of water. While Lake Superior is not as large as the oceans which stabilize east and west coast regions, the effect can be quantified nonetheless. Minnesota is also host to abundant levels of primary producers which increase latent heat absorption and equalize the diurnal temperature range throughout the day.

Source: http://law2.umkc.edu/faculty/projects/ftrials/superior/lsm_map2.jpg

Ancient Ice Age and the distribution of glaciers ice across continents.
Source: http://en.wikipedia.org/wiki/File:Northern_icesheet_hg.png

Following a fairly expected trend for the temperate land locked region, the graph below shows strong seasonality in Minneapolis with the coldest month being January and the warmest month being July. Comparing the precipitation chart to the temperature chart increases in precipitation seem to correspond and predictably show what is typical of the humid temperate climate that it is.

Comparing Minneapolis to other climates in the area brings us to a similar latitude with costal boundaries. Boston Massachusetts has roughly the same longitudinal coordinates and similar temperate climate. Boston experiences seasons like Minneapolis and the wettest month correspond with the warmest month are similar as well. Boston has several river bodies in close proximity to the city center which helps reduce the temperature nearby and provide a similar effect afforded to the city of Minneapolis in regards to its many lakes and streams. Boston is also made up of a modest sized downtown which stores latent heat and releases it at night. This process know as the urban heat island effect would probably have similar consequences in Minneapolis’ modest sized downtown.

Boston, MA Source: http://blastmagazine.com/wp-content/uploads/2009/09/charles_river.jpg

Boston does posses some distinct differences especially in relation to its proximity towards the ocean. The continentality of Minneapolis should produce large ranges of diurnal temperatures which would starkly contrast Boston. In some ways this is accurate but the abundance of water surrounding the city makes contrasting the two location slighlty more difficult. Observing the climographs of Boston one might notice that the rise and decline in temperature throughout the season is rather predictable. A nice smooth curve makes up the average high and low temperature throughout the year. Minneapolis' weather in contrast can be highly unpredictable leading to floods, heat waves and drought. Many years of living in Minneapolis one might perceive the ever-present, cautious optimism which exists among the residents, that the rain will come soon and rejuvenate the land to bring forth the rich foliage that in years past, blanketed the prairie land. 

Minneapolis, MN Source: https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiivptNUgaVJJKQ_PaymYK4VSaPYCcUefJ-UE6G94s8_Spe_2fKtY05PleOclb3LXN7Fn_CTaYnEEFE8fXn47rXXoFT4_Bc2xVCocTP-nE-i6Es5j-oxtmB7njfoO6ddo5EUPeembpQlJA/s1600/Minneapolis.jpg

Forecasting and understanding the principles that make up a particular climate are dynamic and multifaceted. There is no one single element that can account for the multitudes of complexities which exist in climates around the world. All that can be done is understand the mechanics which make up the countless variables and attempt to build interpretive models around those mechanisms. The great thing about weather is regardless of how predictable or variable a particular climate is, we know the Earth's systems are constantly changing and it will be the job of some brave scientists to lead us into that great unknown that drives innovation and strengthens our resolve in the pursuit of exploration.


Thanks to Matt Johnson and his blog on Boston, Massachusetts.

Air and Cyclones

The principle climate of Minnesota in punctuated by two primary seasons. The winter and summer seasons of Minnesota are influenced by two to three main air masses. In the Summer continental polar fronts will make hot, unbearably humid days drier and more mild. The warm air masses come from the south and travel upwards from the Gulf of Mexico constituting a maritime tropic airmass. In the winter as the jet stream descends towards the lower latitudes in the United States the continental polar air mass reaches farther down contributing to the dominant temperature and weather in Minnesota. 

The Jet stream during the winter and summer. Photo courtesy of nc-climate.ncsu.edu

The air masses of North America. Photo courtesy of www.fas.org

During the summer months and especially in July, interactions between the cool, dry continental polar air masses and the warm, wet maritime tropical air masses from the gulf collide to create an active thunderstorm season. In the summer, when the jet stream hovers near the latitude of central Minnesota warm and cold fronts converge and create strong areas of low pressure which fuel thunderstorms and even tornadoes. While I lived in Minnesota I can recall countless tornado warnings that urged people to seek shelter and stay indoors. I had personally never encountered a tornado within a dangerous proximity but the danger always seemed quite real. The video below offers what it was like as a child experiencing tornado season first hand. 

When the southern and northern airmasses occlude the occlusion takes place as a cold occlusion as the cold air mass will typically be colder then the air mass in front of it. As the cold air mass pushes the warm air mass above it clouds form and precipitation may take place. 

There are some factors that are unique to my area. Though not in the immediate vicinity, northern Minnesota, which is very close to Lake Superior experiences weather similar to what one might expect in a maritime environment. 

With relatively warmer weather than the rest of Minnesota in the winter and cooler weather in the summer, northeast Minnesota has a very unique climate. Additionally, phenomenon similar to how the chinook winds work in the Rockies, the Coteau des Prarie can warm cities to the north. In the winter months Alberta clippers, which are fast moving areas of low pressure blow through the region bringing different sorts of weather patterns with them that contribute to the snow storms with them. Panhandle hooks also make their way to Minnesota which act as areas of low pressure originating from the southwest. 

Alberta Clipper. Photo courtesy of wx-man.com

Sources:
- Keen, Richard (1992). Minnesota Weather. American and World Geographic Publishing.
- Palmer, Chad. "Alberta Clippers reinforce cold air". USA Today. http://www.usatoday.com/weather/tg/wclipper/wclipper.htm
- USA Today -> http://usatoday30.usatoday.com/weather/tg/wamsorce/wamsorce.htm
- "Lake Superior Uplands". Minnesota DNR. http://www.dnr.state.mn.us/ecs/212Lb/index.html.

Weather Station by Sam Epperly

The weather station I have chosen is located in Minneapolis, MN in a neighborhood called, Linden Hills. The area rests between two lakes, which define the area and social environment. The Linden Hills neighborhood is located near the 42nd parallel and falls under the classification of a humid continental climate or deciduous forest biome.

The weather station is named "KMNMINNE53" and is located at 947ft elevation. The graphs below indicate average temperature and precipitation.

Source: http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=KMNMINNE53



Another view of the annual temperature throughout the year in the Minneapolis/St. Paul area over a 30 year period.



Source: http://www.rssweather.com/climate/Minnesota/Minneapolis-St.Paul/

Winter in this area spans almost six months and the greatest precipitation generally occurs between March and August, which coincides with the higher temperatures detected throughout the year. During the winter months (Mid October- March) much of the precipitation recieved comes in the form of snow and sticks around for a much longer period. The humidity of the region plays another important role in this consideration as the high humidity percentage allows precipitation to remain for extended periods of time regardless of the state the water falls in.

Source: http://www.tcdailyplanet.net/neighborhood/minneapolis/linden+hills

Map highlighting the Linden Hills Neighboorhood
Source: Google Maps

The two lakes, show above, were once swamps which contributed to the high level of primary productivity in the area as well as the dense tree clusters that dominate in the area. During the migration of more and more human populations into the region these bodies of water were cleaned and dredged of silt and seaweed, and algae. They must continue to be maintained, fighting against the constant battle brought on by artificial utrophication from surrounding affluent neighborhoods.

High concentrations and populations of trees and large volumes of water act to absorb large amounts of radiation. The typical bowen ratio for North America is about .76. Near the Linden Hills area I would expect the bowen ratio to result in a slightly smaller figure (.7-.6) because of the amount of plant life and water bodies available to absorb the insolation. While the area could be described as continental, the close proximity to the two lakes could result in more maritime like characteristics.

 

 

Additional Sources:



-
The weather station I have chosen is located in Minneapolis, MN in a neighborhood called, Linden Hills. The area rests between two lakes, which define the area and social environment. The Linden Hills neighborhood is located near the 42nd parallel and falls under the classification of a humid continental climate or deciduous forest biome.

The weather station is named "KMNMINNE53" and is located at 947ft elevation. The graphs below indicate average temperature and precipitation.

Source: http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=KMNMINNE53



Another view of the annual temperture throughout the year in the Minneapolis/St. Paul area over a 30 year period.



Source: http://www.rssweather.com/climate/Minnesota/Minneapolis-St.Paul/

Winter in this area spans almost six months and the greatest precipitation generally occurs between March and August, which coincides with the higher temperatures detected throughout the year. During the winter months (Mid October- March) much of the precipitation recieced comes in the form of snow and sticks around for a much longer period. The humidity of the region plays another important role in this consideration as the high humidity percentage allows precipitation to remain for extended periods of time regardless of the state the water falls in.

Source: http://www.tcdailyplanet.net/neighborhood/minneapolis/linden+hills

Map highlighting the Linden Hills Neighboorhood
Source: Google Maps

The two lakes, show above, were once swamps which contributed to the high level of primary productivity in the area as well as the dense tree clusters that dominate in the area. During the migration of more and more human populations into the region these bodies of water were cleaned and dedged of silt and seaweed, and algae. They must continue to be maintained, fighting against the constant battle brought on by artifical utrophication from surrounding affluent neighboorhoods.

High concentrations and populations of trees and large volumes of water act to absorb large amounts of radiation. The typical bowen ratio for North America is about .76. Near the Linden Hills area I would expect the bowen ratio to result in a slightly smaller figure (.7-.6) because of the amount of plant life and water bodies available to absorb the insolation. The area would be classified as continental, however, given the sloe proximity to the surrounding lakes, many of the characteristics might be more similar to maritime.

Additional Sources:
-
The weather station I have chosen is located in Minneapolis, MN in a neighborhood called, Linden Hills. The area rests between two lakes, which define the area and social environment. The Linden Hills neighborhood is located near the 42nd parallel and falls under the classification of a humid continental climate or deciduous forest biome.

The weather station is named "KMNMINNE53" and is located at 947ft elevation. The graphs below indicate average temperature and precipitation.

Source: http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=KMNMINNE53



Another view of the annual temperture throughout the year in the Minneapolis/St. Paul area over a 30 year period.



Source: http://www.rssweather.com/climate/Minnesota/Minneapolis-St.Paul/

Winter in this area spans almost six months and the greatest precipitation generally occurs between March and August, which coincides with the higher temperatures detected throughout the year. During the winter months (Mid October- March) much of the precipitation recieced comes in the form of snow and sticks around for a much longer period. The humidity of the region plays another important role in this consideration as the high humidity percentage allows precipitation to remain for extended periods of time regardless of the state the water falls in.

Source: http://www.tcdailyplanet.net/neighborhood/minneapolis/linden+hills

Map highlighting the Linden Hills Neighboorhood
Source: Google Maps

The two lakes, show above, were once swamps which contributed to the high level of primary productivity in the area as well as the dense tree clusters that dominate in the area. During the migration of more and more human populations into the region these bodies of water were cleaned and dedged of silt and seaweed, and algae. They must continue to be maintained, fighting against the constant battle brought on by artifical utrophication from surrounding affluent neighboorhoods.

High concentrations and populations of trees and large volumes of water act to absorb large amounts of radiation. The typical bowen ratio for North America is about .76. Near the Linden Hills area I would expect the bowen ratio to result in a slightly smaller figure (.7-.6) because of the amount of plant life and water bodies available to absorb the insolation. The Linden Hills neighborhood may be classified as continental, however, given the close proximity to the two surrounding lakes, the area may also have some characteristics of maritime.

 

 

Additional Sources:

 

- http://www.weather.com/outlook/travel/businesstraveler/wxclimatology/monthly/graph/USMN0503

- http://www.rssweather.com/climate/Minnesota/Minneapolis-St.Paul/

- Bowen, I.S., 1926: The ratio of heat losses by conduction and by evaporation from any water surface. Physical Review, 27, pp 779–787.