In order to investigate the effects of geography on climate, I selected
two cities, both on the same continent, both at approximately the same
latitude, and both on major bodies of water. I compared the monthly
temperature and precipitation averages of New York City with the monthly
temperature and precipitation averages of San Francisco.
I also recorded the
daily temperatures of the two cities over the course of three months. What I
found is reflected in this report.
New York City and San Francisco are very similar. New York is at
38 north latitude and San Francisco is located at 41 north Latitude. Each
borders an ocean.
New York is on the east coast of the United States, on the
Atlantic Ocean; San Francisco is on the west coast, on the Pacific Ocean.
New Yorks climate varies widely during the year. The temperature
rises to the middle 90s Fahrenheit in the summer and drops to single digits
in the winter. New York averages about 45 inches of precipitation per year.
In San Francisco, the temperature rises to over 100 Fahrenheit.
By
comparison, the temperature usually does not drop below 20 Fahrenheit.
San Francisco receives little rain compared to New York, only about 15
inches of precipitation per year, about one-third of New Yorks average.
Heat is a result of insolation. Insolation is radiation from the sun.
Intensity of insolation goes down as the latitude of an area increases. Thus, a
location at 10 north latitude will receive more intense insolation than a
location at 75 north latitude.
As intensity of insolation goes up, the temperature will increase.
Air pressure measures the amount of force exerted on the air. Air
pressure goes up as the temperature goes up.
New Yorks average monthly temperature varies very much. The
highest average temperature is 76 Fahrenheit, in July; the lowest average
temperature is 31 Fahrenheit, in January. San Franciscos average
temperature does not vary as much.
The highest average temperature is 61
Fahrenheit, in September; the lowest average temperature per month is 47
Fahrenheit, in December. New Yorks average temperature per month varies
very much more than San Franciscos.
Water moderates temperature. A city close to an ocean will have
cooler summers and warmer winters. Both New York and San Francisco
border water.
Most of New York City is an island in the Atlantic Ocean.
San Francisco is on the Pacific Ocean. The temperatures in New York and
San Francisco will, therefore, be moderated.
Graph #1 shows the results of these affects on the temperature of New
York and San Francisco.
The dewpoint temperature is the temperature at which clouds form.
If
there is moisture in the air from evaporation and the air temperature meets
dewpoint temperature, the moisture will condense to form clouds. When there
are clouds, and the air pressure goes up, there is a chance of precipitation.
Precipitation is likely because the air can not hold as much water.
New York has more precipitation than San Francisco. New Yorks
temperature drops very far in the winter, and the cold air cannot hold as much
water. San Franciscos temperature does not drop as far, and so it can hold
more water.
In July and August, San Francisco averages no precipitation.
There is not very much moisture in the air and the temperature does not go
down very far, so it does not precipitate at all.
Graph #2 shows the average amount of precipitation per month for
New York and San Francisco.
Graph #3 shows the high and low temperatures for each day of
December, 1996, in New York and San Francisco. Graph #4 shows the high
and low temperatures for each day of January, 1997, in New York and San
Francisco. Graph #5 shows the high and low temperatures for each day of
February, 1997, in New York and San Francisco.
The graphs reflect erratic highs and lows because of different changes
in the weather, which could be attributed to any atmospheric changes. For
example, an approaching storm could make the temperature fall several
degrees.
New York and San Francisco are similar because they are both close to
water and because both are at approximately the same latitude. The climates
in the two cities, however, are very different.
The temperature in San
Francisco does not change very much compared to the temperature of New
York, where the temperature differs very much, from month to month.
New York receives much more precipitation than San Francisco. This
is because the temperature does not dip down very far in San Francisco, so
the air can hold more moisture.
In summary, New York and San Francisco are similar because of their
locations, but they have very different climates, as this paper shows.
