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 by 6°F at each step north, the drop seen from Miami to New York
   • 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
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: the swing is smallest at Utqiagvik, where sunlight is least in the four cities
   • Not quite: it grows to Utqiagvik, but New York's 44°F is a degree more than Anchorage's 43°F
   • No: Miami has the biggest swing, because it has the warmest July of the four cities
   • Yes: each city farther north has a bigger swing than the city before it, so it grows steadily north
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?

   • The January gap equals the 35 degrees of latitude between the two cities
   • 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
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?

   • 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
   • Climate is the most common temperature, so 72°F becomes the climate if it happens again
   • Weather and climate are the same thing, since both are measured in degrees
6. 5.

   Anchorage's January normal is 17°F and its July normal is 60°F. Miami's are 69°F and 84°F. Which statement does Kira support?

   • Anchorage's swing, 43°F, is nearly three times Miami's swing of 15°F
   • Anchorage's swing is about twice Miami's, since its July is 24°F colder than Miami's
   • Miami's swing is larger than Anchorage's, because Miami has the warmest July
   • Anchorage's swing is 43°F more than Miami's, so it is about 58°F
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
   • 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
   • No: Utqiagvik is at 71°N, beyond the polar circles, so just Miami's value is a share
8. 7.

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

   • New York gets more than Miami, since it lies closer to 45° and that band holds 70%
   • Miami gets a little under the tropics' 90%, and New York a little more than 45°'s 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
9. 8.

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

   • Season matters more than latitude everywhere, so winter in Miami beats summer in Anchorage
   • Anchorage must be cold because it is 61°N, so its July cannot be 60°F
   • A place at 26°N in its coldest month can be warmer than one at 61°N in its warmest
   • Miami is warmer in January just because its July is warmer, so July sets January
10. 9.

    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 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
    • They give each month's temperature, since the equinox is a typical day for each month
    • They show which latitudes are sunnier on average, but they do not give each month's temperature
11. 10.

    NOAA normals average 30 years, while NASA's sunlight shares describe one moment. Zee sets them side by side. What should Zee keep in mind?

    • They fit together as a general pattern, but they measure different things over different spans
    • They measure the same thing, so differences between them show errors in one of them
    • The shares explain the whole of each normal, so no other factor needs to be considered
    • A 30-year average is more accurate than a single moment, so the normals replace the shares for any city