Climate



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 York’s climate varies widely during the year. The temperature

rises to the middle 90’s ° 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 York’s 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 York’s 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 Francisco’s 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 York’s average temperature per month varies

very much more than San Francisco’s.

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 York’s

temperature drops very far in the winter, and the cold air cannot hold as much

water. San Francisco’s 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