What makes climate, and the world's biomes

Grade 9 Social Studies Worksheet - Building Confidence

Circle the best answer.

1. Read this first

   Four cities and the sunlight at their latitudes

   City	Latitude (about)	January normal (°F)	July normal (°F)
   Miami	26°N	69	84
   New York	41°N	34	78
   Anchorage	61°N	17	60
   Utqiagvik, Alaska	71°N	-12	42

   Note: NOAA 1991-2020 normals are averages over 30 years. Weather is the conditions on one day. NASA: at an equinox, sunlight reaching the ground is about 90% of the equator's in the tropics, about 70% at 45° and about 40% at the polar circles (66.5°).

2. 1.

   Ari says each step north cools July by about the same amount. Compare July in the four cities. Is that right?

   • Yes: July falls about 14°F at each step north, since 84 minus 42 is 42 over three steps
   • No: July falls 6°F from Miami to New York, then 18°F twice, to Anchorage and to Utqiagvik
   • No: July falls 15°F from Miami to New York, the same as the change in degrees of latitude
   • Yes: July falls by 6°F at each step north, the drop seen from Miami to New York
3. 2.

   July minus January is 15°F in Miami, 44°F in New York, 43°F in Anchorage and 54°F in Utqiagvik. Bo says the swing grows steadily with latitude. Is that right?

   • No: Miami has the biggest swing, because it has the warmest July of the four cities
   • Not quite: it grows to Utqiagvik, but New York's 44°F is a degree more than Anchorage's 43°F
   • Yes: each city farther north has a bigger swing than the city before it, so it grows steadily north
   • No: the swing is smallest at Utqiagvik, where sunlight is least in the four cities
4. 3.

   Sunlight falls from about 90% in the tropics to about 70% at 45°. New York's January is 35°F colder than Miami's. What can Esme say about the two facts?

   • Sunlight cannot affect January, since the sun is weakest in winter at each latitude, so another cause is at work
   • Less sunlight fits the colder January, but no card gives a rule turning sunlight points into degrees
   • Each point of sunlight lost cools January by 1.75°F in each city, since 35 divided by 20 is exactly 1.75
   • The January gap equals the 35 degrees of latitude between the two cities
5. 4.

   One July day in Anchorage reaches 72°F. Jun says Anchorage's July climate is therefore 72°F, not the 60°F normal. What is the reply?

   • Climate is the most common temperature, so 72°F becomes the climate if it happens again
   • A normal is a 30-year average, so one hot day is weather and does not change the 60°F normal
   • The 60°F normal must be wrong, since one day hotter than the normal shows it is too low
   • Weather and climate are the same thing, since both are measured in degrees
6. 5.

   Utqiagvik's January normal is -12°F. Luz says no January day there is ever warmer than 0°F. What is wrong with that?

   • A 30-year average cannot be used for single days, so Utqiagvik has no January climate
   • A normal is an average, so some January days can be warmer than it and some colder
   • The normal means each January day is colder than -12°F, since it is a long-term low
   • Nothing, since a normal sets the highest temperature that can occur on any January day
7. 6.

   Utqiagvik's January normal is -12°F and Miami's is 69°F. Milo says the polar circles get 40% of the tropics' sunlight, so -12°F is 40% of 69°F. Is that sound?

   • No: -12°F is below zero, so it cannot be 40% of 69°F; temperature does not scale with sunlight
   • No: Utqiagvik is at 71°N, beyond the polar circles, so just Miami's value is a share
   • Yes: sunlight at the polar circles is 40%, so temperature there must be 40% as well
   • Yes: 40% of 69°F is about 28°F, which is near -12°F once the winter effect is added
8. 7.

   Anchorage lies at about 61°N, between 45° (about 70%) and the polar circle at 66.5° (about 40%). How much of the equator's sunlight does Noah expect?

   • Under 40%, since Anchorage is past the polar circle
   • Between about 40% and 70%, since 61° lies between the two bands
   • About 90%, since Anchorage is in the Northern Hemisphere with the tropics
   • Exactly 55%, the middle of 40% and 70%, since 61° is the middle of the bands
9. 8.

   Miami is at 26°N, just outside the tropics, and New York at 41°N. Which statement fits their sunlight, Pia?

   • Miami gets a little under the tropics' 90%, and New York a little more than 45°'s 70%
   • New York gets more than Miami, since it lies closer to 45° and that band holds 70%
   • Both get about 70%, since both lie between the tropics and 45° and share a band
   • Miami gets a little more than 90%, and New York a little under 70%, since both are warm cities
10. 9.

    Miami's January normal, 69°F, is warmer than Anchorage's July normal, 60°F. What does Ren learn from that?

    • Anchorage must be cold because it is 61°N, so its July cannot be 60°F
    • Season matters more than latitude everywhere, so winter in Miami beats summer in Anchorage
    • Miami is warmer in January just because its July is warmer, so July sets January
    • A place at 26°N in its coldest month can be warmer than one at 61°N in its warmest
11. 10.

    The sunlight shares are for an equinox. Tala lines them up with each city's July and January normals. What is a fair view?

    • They show which latitudes are sunnier on average, but they do not give each month's temperature
    • They give each month's temperature, since the equinox is a typical day for each month
    • They are useless for temperature, since they describe a single moment
    • They tell the January temperature, but not the July one, since the equinox is in spring