Exercise 10 Part I

1.

a. January 10:

 Declination: Approximately -21.5 degrees

 Latitude: South latitude

b. March 6:

 Declination: Approximately -5 degrees

 Latitude: South latitude (close to equinox, moving towards north)

c. May 9:

 Declination: Approximately +15 degrees

 Latitude: North latitude

d. November 18:

 Declination: Approximately -20 degrees

 Latitude: South latitude
2.

(a) January 10 at 0° latitude (Equator)

Declination: From the analemma (as calculated previously), the declination of the Sun on
January 10 is about 21° South.
 Arc Distance (AD): Since the location is on the equator (0°), the arc distance is:
AD=∣0°−(−21°)∣=21°AD = |0° - (-21°)| = 21°AD=∣0°−(−21°)∣=21°

 Solar Altitude (SA):

SA=90°−21°=69°SA = 90° - 21° = 69°SA=90°−21°=69°

Solar Altitude on January 10 at the equator: 69°

(b) March 6 at 38°N latitude

 Declination: From the analemma, the declination of the Sun on March 6 is approximately
5° South.
 Arc Distance (AD): For a location at 38°N, the arc distance is:
AD=∣38°N−(−5°S)∣=38°+5°=43°AD = |38°N - (-5°S)| = 38° + 5° = 43° AD=∣38°N−
(−5°S)∣=38°+5°=43°

 Solar Altitude (SA):

SA=90°−43°=47°SA = 90° - 43° = 47°SA=90°−43°=47°

Solar Altitude on March 6 at 38°N: 47°

(c) May 9 at 70°S latitude

 Declination: From the analemma, the declination of the Sun on May 9 is approximately
18° North.
 Arc Distance (AD): For a location at 70°S, the arc distance is:
AD=∣70°S−18°N∣=70°+18°=88°AD = |70°S - 18°N| = 70° + 18° =
88°AD=∣70°S−18°N∣=70°+18°=88°

 Solar Altitude (SA):

SA=90°−88°=2°SA = 90° - 88° = 2°SA=90°−88°=2°

Solar Altitude on May 9 at 70°S: 2°

Exercise 11 Part I
1.

2. Questions Based on the Chart:

(a) On June 22, at which latitude (the equator or 45°N) is the noon Sun highest in the sky?
On June 22 (the summer solstice in the Northern Hemisphere):
At the equator (0° latitude), the Sun is not directly overhead but at a significant angle.
At 45°N, the Sun is higher in the sky because June 22 is near the Tropic of Cancer (23.5°N),
meaning the Sun's declination is close to 23.5°N.
Answer: The noon Sun is highest at 45°N on June 22.
(b) Does the noon Sun at the North Pole ever get as high as it is on January 22 at 45°N?
On January 22, the Northern Hemisphere is in winter:
At 45°N, the Sun is very low in the sky, given the tilt of the Earth and the proximity to the winter
solstice.
At the North Pole, the Sun does not rise at all during this time (polar night).
The Sun at the North Pole never gets as high as the Sun at 45°N on January 22. In fact, during
winter months, the Sun doesn’t rise at the North Pole.
Answer: No, the Sun at the North Pole does not get as high as it is at 45°N on January 22.
3. Insolation Based on Solar Altitude at Noon:
(a) Which of the three latitudes (equator, 45°N, or 90°N) would receive the highest insolation on
June 22?
On June 22, the summer solstice, the Sun is directly overhead at 23.5°N (Tropic of Cancer).
Therefore, the Sun’s rays are more direct at 45°N, as it is closer to the Tropic of Cancer.
The equator would not receive as much direct sunlight on this date because the Sun is to the
north.
At 90°N (the North Pole), the Sun is above the horizon for 24 hours, but at a lower angle,
meaning insolation is weaker despite the continuous daylight.
Answer: 45°N would receive the highest insolation on June 22.
(b) Which of the three latitudes would receive the lowest insolation on June 22?
At the North Pole (90°N), while the Sun is up for 24 hours, the angle of incidence is low,
resulting in weaker solar energy.
The equator and 45°N receive stronger sunlight due to their proximity to the Tropic of Cancer.
Answer: 90°N (the North Pole) would receive the lowest insolation on June 22 due to the lower
solar altitude.
(c) Which latitude receives the highest insolation on December 22?
Equator (0°):
On December 22, the Sun is directly overhead at the Tropic of Capricorn (23.5°S). This means
the equator has a solar altitude of about 66.5°, which is high compared to higher latitudes.
The equator still receives significant insolation since the solar angle is relatively high.
Conclusion: The equator would receive the highest insolation on December 22.
(d) Which latitude receives the lowest insolation on December 22?
90°N (North Pole):
On December 22, the North Pole experiences polar night, meaning the Sun doesn’t rise at all.
There is no solar altitude, and thus zero insolation at 90°N during the winter solstice.
45°N:
At 45°N, the solar altitude is low, around 21.5°, meaning it would receive some insolation, but
much less compared to the equator.
Conclusion: The 90°N (North Pole) would receive the lowest insolation on December 22, as it
experiences complete darkness during this period.
7.
(a) For how many months of the year does the North Pole receive no insolation?
The North Pole receives no insolation for approximately 6 months of the year. This period
corresponds to the time when the Sun does not rise above the horizon at the North Pole, known
as the polar night. During this time, the solar altitude at noon is 0°.
(b) Which dates mark the beginning and end of this period of zero insolation at the North Pole?
-Beginning: The period of zero insolation starts at the Autumnal Equinox (around September
22), when the Sun sets and doesn't rise for six months. End: The period ends at the Spring
Equinox (around March 22), when the Sun rises again and remains above the horizon for six
months during the polar day.
Exercise 12 Part III
1.Which factor primarily explains the different temperature patterns of St. Louis and Oakland?
The primary factor that explains the difference in temperature patterns between St. Louis and
Oakland is proximity to large bodies of water, which creates a continental vs. maritime climate.
St. Louis, Missouri, is located inland at 38.6°N latitude and does not have a nearby ocean to
moderate its temperatures. As a result, it experiences a humid continental climate(Köppen: Dfa),
characterized by hot summers and cold winters. The temperature range is high because land
heats up and cools down faster than water. This leads to:

- July average high temperature**: 89°F (32°C)

-January average low temperature**: 23°F (−5°C)

-Annual temperature range**: ~66°F (37°C)

Oakland, California, at 37.8°N latitude, sits on the coast of the Pacific Ocean. The nearby Pacific
Ocean has a moderating influence on Oakland's temperatures, resulting in a Mediterranean
climate (Köppen: Csb), characterized by mild, wet winters and dry summers. The ocean absorbs
heat slowly during summer and releases it slowly during winter, keeping temperatures stable.
The cold California Current also cools the coastal air, leading to:

-July average high temperature: 73°F (23°C)

-January average low temperature: 45°F (7°C)

-Annual temperature range: ~28°F (16°C)

Thus, Oakland's proximity to the ocean and the moderating effect of the Pacific Ocean explain its
milder, less variable temperatures compared to the more continental climate of St. Louis.

### 2. **Why does St. Louis have colder winters than Norfolk?**

Latitude and proximity to water are the two key factors that explain why St. Louis has colder
winters than Norfolk. St. Louis is located at 38.6°N, further inland and at a higher latitude than
Norfolk, which results in less solar energy during the winter months. Additionally, St. Louis is
far from any major water bodies, so it lacks the temperature-regulating effects of the ocean. The
continental polar (cP) air masses often sweep across the Midwest in winter, bringing cold, dry
conditions.

-January average temperature: 32°F (0°C)

-Record low temperature: −22°F (−30°C)

 -Norfolk, Virginia, at 36.9°N, is a coastal city on the Atlantic Ocean. The Atlantic Ocean acts as
a thermal buffer, absorbing heat during summer and releasing it in winter, keeping coastal areas
warmer. Additionally, the Gulf Stream, a warm Atlantic Ocean current, flows near the U.S. East
Coast and contributes to Norfolk's milder winters. Norfolk's climate is classified as humid
subtropical (Köppen: Cfa), characterized by mild winters and hot summers.

-January average temperature: 45°F (7°C)

-Record low temperature: 3°F (−16°C)

Although both cities are at similar latitudes, St. Louis experiences colder winters due to the lack
of oceanic influence and the exposure to cold continental air masses, while Norfolk benefits from
the Atlantic Ocean's moderating effect.

### 3. **Although both are coastal cities, compared to Oakland, Norfolk has a very "continental"
temperature pattern. Why?**

Norfolk's more "continental" temperature pattern, despite being a coastal city, can be attributed
to ocean currents and prevailing wind patterns. Oakland is on the Pacific Coast, where the
California Current, a cold ocean current, flows southward along the coast, cooling the
surrounding air. This, combined with prevailing westerly winds (which blow from ocean to
land), keeps Oakland's temperatures mild and relatively stable throughout the year. Oakland’s
Mediterranean climate (Csb) is marked by:

-July average high temperature: 73°F (23°C)

-January average low temperature: 45°F (7°C)

-Annual temperature range: ~28°F (16°C)

-Norfolk, while coastal, is on the Atlantic Ocean, and experiences the influence of the Gulf
Stream, a warm ocean current. However, Norfolk also has prevailing westerly winds, which
blow from the interior of the continent, bringing warm air in summer and cold air in winter. This
results in a more continental pattern, where the annual temperature range is higher than
Oakland’s.

-July average high temperature: 89°F (32°C)

- January average low temperature: 32°F (0°C)

-Annual temperature range: ~57°F (32°C)

Despite both being coastal cities, the cold California Current and onshore winds in Oakland
provide more temperature moderation compared to Norfolk's combination of warm Gulf Stream
waters and inland airflow, leading to a higher temperature variability in Norfolk.
4.Which factor primarily explains the difference in temperature patterns between Fairbanks and
St. Louis?

The key factor explaining the difference in temperature patterns between Fairbanks and St. Louis
is latitude. Fairbanks, Alaska, is located at 64.8°N, deep within the subarctic climate zone
(Köppen: Dfc). Due to its high latitude, Fairbanks experiences extremely long winter nights and
long summer days, leading to significant seasonal temperature variation. Winter temperatures in
Fairbanks can drop drastically, especially due to the frequent presence of Arctic air masses (cA).
The lack of nearby large bodies of water allows for greater temperature extremes:

- January average low temperature: −17°F (−27°C)

-July average high temperature: 72°F (22°C)

-Annual temperature range: ~89°F (50°C)

-St. Louis lies at a much lower latitude of 38.6°N in a *humid continental climate (Dfa).
Although it also experiences cold winters and hot summers, the latitude allows for more solar
energy and more temperate conditions year-round compared to Fairbanks:

-January average low temperature: 23°F (−5°C)

-July average high temperature: 89°F (32°C)

-Annual temperature range: ~66°F (37°C)

The higher latitude of Fairbanks results in much colder winters and a larger annual temperature
range compared to St. Louis, which benefits from its lower latitude and increased solar energy.

5.Which factor primarily explains the difference in temperature patterns between Fairbanks and
Nome?

The primary factor explaining the difference in temperature patterns between Fairbanks and
Nome is proximity to the ocean. Fairbank sis located inland and experiences a continental
subarctic climate (Dfc), with extreme temperature variations due to its distance from moderating
ocean influences. This results in harsher winters and warmer summers:

January average low temperature: −17°F (−27°C)

July average high temperature: 72°F (22°C)

Nome, Alaska, located on the coast of the Bering Sea, at 64.5°N, experiences a subarctic
maritime climate (Dfc), meaning that the ocean moderates its temperatures. The Bering Sea
prevents Nome from experiencing the extreme cold of Fairbanks during the winter:
 January average low temperature: 6°F (−14°C)

July average high temperature: 58°F (14°C)

Nome’s proximity to the Bering Sea significantly moderates its winter temperatures, resulting in
a less extreme temperature range compared to inland Fairbanks.

6. Why does Lihue have a smaller annual temperature range than Oakland?

The smaller annual temperature range in Lihue, Hawaii, compared to Oakland is due to tropical
latitude and the surrounding warm ocean waters. Lihue, located at 21.98°N on the Hawaiian
island of Kauai, experiences a tropical climate (Köppen: Af), where temperatures are warm and
consistent year-round. The surrounding Pacific Ocean remains warm throughout the year and has
a significant moderating influence on temperatures. As a result, Lihue's temperature range is very
small:

January average temperature: 72°F (22°C)

July average temperature: 79°F (26°C)

Annual temperature range: ~7°F (4°C)

Oakland, while having a Mediterranean climate, still experiences more seasonal variability due
to its location in a temperate zone and the cooler California Current:

January average low temperature: 45°F (7°C)

July average high temperature: 73°F (23°C)

Annual temperature range: ~28°F (16°C)

The tropical location and the warm Pacific Ocean surrounding Lihue result in a smaller annual
temperature range compared to Oakland.

7.What explains the difference in temperature patterns between Lihue and Kilauea?

The primary factor that explains the difference between Lihue and Kilauea is elevation. Lihue is
located at sea level on Kauai and experiences a warm, consistent tropical climate due to the
proximity to the warm Pacific Ocean. Annual temperature range: ~7°F (4°C) Kilauea, on the Big
Island of Hawaii, is situated at a much higher elevation. The temperature decreases with altitude,
a phenomenon known as the environmental lapse rate, where temperatures drop approximately
3.5°F per 1,000 feet(6.5°C per kilometer) of elevation. Kilauea’s volcanic terrain rises to
elevations of over 4,000 feet, resulting in cooler conditions compared to coastal areas like Lihue.
At the summit of Kilauea, temperatures can vary significantly from sea level locations,
especially during nighttime, where they can dip to near-freezing at high altitudes, even though it
lies in the tropics.