1. What is the approximate average 500 mb height over Tucson for the month of January? What is the approximate average 500 mb height over Tucson for the month of August? What is the basic reason for the difference in 500 mb height between August and January?
2. Write down the simple rule for the 500 mb wind direction based on the 500 mb height pattern shown on 500 mb weather charts. You do not need to discuss the forces that determine wind direction to answer this question. The simple rule for 500 mb wind direction is provided at the top of the second reading page. Using the simple rule for the 500 mb wind direction based on the 500 mb height pattern, determine and describe the air flow or wind pattern around a circular closed high at 500 mb. Do the same thing for a circular closed low at 500 mb.
3. What is the meteorological definition of a "monsoon?" Describe how the 500 mb height pattern and 500 mb winds change as the southwestern United States moves into the summer monsoon pattern.
4. The Tucson National Weather Service webpage provides today's weather observation data including temperature, dew point temperature, relative humidity, wind speed, wind direction, clouds, visibility, station pressure (inches) and 6 hour forecast. Use this link: to
find these data at 4:53 am and 4:53 pm. Please include units.
5. One way to specify the total amount of the gas water vapor in the atmosphere above a given place on the Earth's surface is in units of precipitable water. The most recent precipitable water loop can be seen from here: https://tropic.ssec.wisc.edu/realtime/mimic-tpw/global2/main.html .What is "precipitable water?" Can we use "precipitable water" directly to forecast precipitation? Why or why not?
6. What is the Intratropical Convergence Zone (ITCZ) and where is it located on Earth? How does the ITCZ appear on satellite images? You can show me a satellite image with the ITCZ labeled.
7. Describe the surface air pressure pattern and the surface wind pattern around a tropical cyclone in the Northern Hemisphere. What is the relationship between the surface pressure at the center of a tropical storm and the wind speed? Briefly explain the reason for this relationship. Is the surface wind pattern, converging, diverging or neither? Does this force rising air motion, sinking air motion, or neither?
8. How does the North Atlantic Ocean compare against other tropical ocean basins in terms of hurricane activity, i.e., the average number of tropical storms and hurricanes that form each year? Which ocean basin produces the most hurricanes? Which two tropical ocean basins rarely produce hurricanes and why?
9. Suppose you read an article about a possible connection between global warming and hurricanes. The author claims that there is already evidence for this connection in the recent record of Atlantic Hurricanes. One piece of evidence cited is that hurricane property damage in the United States has been increasing in recent decades, even after adjusting the damage values for inflation, although no other normalization factors were considered. Note: That statement is basically correct. A second piece evidence cited is that there have been more and stronger Atlantic hurricanes in the last 18 years (1995 - 2012) compared to the previous 25 year period (1970 - 1994). Again that statement is basically correct. Do either of these two points provide good evidence that hurricanes are becoming more numerous and intense due to global warming? Briefly explain the reasons for your answers. Please note that this question is not to debate the existence of human caused global warming. The IPCC states that human emissions have very likely caused recent warming, and we will discuss the details of these findings
during week 4.
10. The questions below are based on skew-T #1 and skew-T #2. Links to the skew-T diagrams are also provided below the question. Both skew-T diagrams were based on measurements taken at 12 Z in Tucson. One of the diagrams is from January 2, 2013, and the other is from August 29, 2013.
• Which one is from August and which is from January? Use differences in the 500 mb winds, the 500 mb heights, and surface temperature to justify your answer. The surface temperature is the temperature at the very bottom of the skew-T diagrams.
• Which skew-T diagram has a clear temperature inversion just above ground level? Explain what you see on the skew-T that indicates a temperature inversion.
• Which skew-T diagram indicates the presence of clouds in the atmosphere above Tucson? Explain what you see on the skew-T to indicate the presence of clouds.
Extra credit question:
11. At ground level, the air pressure measured with a barometer is 1000 mb. The barometer is lifted upward by a weather balloon. When the balloon reaches 2 km above the ground, the measured air pressure is 800 mb. Explain why the air pressure decreased. After the balloon goes up another 2 km (now 4 km above the ground), will the measured air pressure be exactly 600 mb, lower than 600 mb, or higher than 600mb?
Explain the reason for your answer. Hint: consider how air density changes with increasing altitude.