Changes in Latitude, Changes in Attitude of the Weather

It comes as no surprise to a grade school student that temperature and length of the day changes with the seasons.  No one is surprised to hear that it gets colder up north, either.  It is difficult, however, to compile a list of cities, north and south of the equator, that illustrate this effectively.  No two cities have precisely the same influences on their weather.  Some areas that would otherwise be cold are close to warm ocean currents that dominate their climate.  Some cities are cold because they are at high altitude even though they are not that far from the equator.  The list I have compiled is not perfect but it takes some of these factors into consideration.  My list doesn’t eliminate enough variables to meet the criteria of a suitable scientific experiment but it does illustrate the seasonal changes in temperature and length of day the earth experiences as it moves around the sun annually.  The images below provide a succinct demonstration of my point.

 

Tracking the Sun Across the Macon Sky

 My goal was to track the sun across the sky and record its angle from Macon.  I determined grid north by using Google Earth to find an image of my apartment.  Then I identified two reference points in my yard that lined up with north. I used them to paint a diagram of the cardinal directions on my driveway.  I discerned the angle to the sun by eye, transferred the angle to the diagram with chalk and measured it with a protractor.  Below is a shot of the diagram I drew in my driveway.

  I gathered the information on temperature and conditions for each observation from The National Weather Service website.  Below is a chart showing that data.

Wind Rose Plots

A wind rose plot is a graphic used by meteorologist to illustrate in a convenient format the typical distribution of wind direction and speed at a given location. The circular graphic typically shows the frequency with which winds blow from each direction. The length of each "spoke" around the circle illustrates the percentage of time that the wind blows from a particular direction. Each concentric circle represents a different frequency from zero at the center, increasing with the distance from the center. emanating from zero at the center to increasing frequencies at the outer circles. Wind roses may also contain wind speed information by breaking each spoke down with color codes to show the frequency with which wind blows from a given direction in certain speed ranges. Typical wind roses show 16 cardinal directions, such as north (N), NNE, NE, etc.

A Typical Wind Rose Plot - Note that data for the plot was 

gathered over an extended period of time.

A Seven-Year Cycle?

The Perfect Storm 

Oct 28 - Nov 4, 1991

Hurricane Issac made its final landfall on the U. S. Gulf coast on Aug 29, 2012, seven years to the day after Hurricane Katrina.  Katrina made landfall on Aug 29, 2005 and was the single most destructive natural disaster in recorded U. S. history.  Katrina also killed more people than any other recorded storm except for the 1928 south Florida hurricane.  Oddly, Hurricane Sandy slammed into the Mid-Atlantic U. S. 2 months later during the 21st anniversary of the Perfect Storm of movie notoriety.  The Perfect Storm, a nor'easter that absorbed Hurricane Grace, never made landfall but it did cause deaths and damage in the northeastern as it battered the coastline.  It is particularly well known because of the 2000 film by the same name that chronicled the sinking of the Andrea Gail, a fishing vessel from Gloucester, MA.  Twenty one years later on Oct 29, 2012, Sandy made landfall as a category 2 hurricane but it was huge; over 1000 nautical miles. These odd coincide of anniversary and 7- and 21-year intervals has prompted some people to speculate about a seven-year cycle for catastrophic storms.  There is no scientific data to support the existence of such a cyclical pattern occurs, however.

Five Types of Maps

Clorpleth Map

A chloropleth map is one which a specific color or pattern is used to identify all areas with the same statistical data for a given variable.  A different color or pattern is used for an area with another set of statistical data.  Chloropleth maps are used to illustrate a variety of subject matter such as demographics or scientific data.  This one illustrates how the electoral vote was divided between Democrats and Republicans in the 2008 Presidential election.

Dot Density Map

A dot density map uses groups of dots to quantitatively represent a given phenomenon or feature.  The more dots there are in an area on the map, the more common the feature or phenomenon.  Dot density maps can be used to demonstrate the distribution of anything from people, frogs, or mosquitoes to manhole covers or yellow cabs in a designated area.  This one shows the distribution of American farms in 1997.

 

Proportional Symbol Map

A proportional symbol map illustrates the variation in distribution of a feature or phenomenon by using a given symbol and simply varying its size proportionally.  These maps may be used in similar ways to chlorpleth and dot density maps.  The map above identifies the number of internet users in each European country in 2004.  Note where the data came from:  the American CIA.  Big brother is watching!

 

Isopleth Map

Isopleth maps, sometimes called contour line maps, depict data that has been collected over an area.  The contour lines connect points where identical statistical data has been collected.  In the example above, data has been compiled over many years.  The lines connect weather data collection stations that demonstrate t the same average rainfall over that period.  Other types of isopleths include topographic maps which show elevation of above sea level for Earth’s terrestrial areas and bathymetric maps which show depth below sea level in aquatic environs.

 

Environmental Sensitivity Map

Environmental Sensitivity Index (ESI) maps identify wildlife, their habitat, and other resources that are vulnerable to the impact of human activity and natural disaster.  The purpose of these maps is to aid planners in setting priorities when preparing strategies to respond to events that threaten an environmentally sensitive area. ESI maps provide planners with information about land type and structure, biological habitation, and human-use resources.  This is cloropleth ESI map of Slovenia identifies areas of vulnerability by indexing each area according to its environmental sensitivity.