ERTH 365.02 Class Notes September 1, 2016 Selina Marasigan & Hermandeep Kaur

Assignment ­ None

Housekeeping & Announcements ­ Received Saffir­Simpson Hurricane Intensity Scale handout ­ Reviewed Weather Map Symbol Handout received on 8/30

Current Weather Discussion We looked at the visible and infrared images of tropical storms Lester and Madeline in the Pacific and discussed the information we saw on the Track Map. We did the same for Hurricane Hermine in the Gulf of Mexico.

Track Map A track map records the day­to­day movement of the center of a hurricane. It plots the position of the storm every six hours. This is useful in predicting the path of the hurricane and recording patterns to predict future hurricanes. The map also shows a grayed out zone around the storm that people should remain clear of. This is especially useful for the navy and others at sea.

Saffir­Simpson Hurricane Intensity Scale In class, we looked at a handout which had the Saffir­Simpson Hurricane Intensity Scale. We discussed patterns such as the following: there were more lines representing hurricanes on the east coast than on the west coast. Also, hurricanes are present as far north as Iceland. Furthermore, orange and red colors on the scale represent the most intense storms which the map shows to be present in the Western Pacific. Observations of the map concludes that hurricanes start up in the east and tend to curve and fan out, beginning to narrow in the Atlantic and Pacific oceans. We also talked about patterns of importance, which in this case would be the fact that there are no hurricanes present near the geographical equators or northern and southern poles. Such observations lead us to formulate questions we can investigate through the scientific method. We asked ourselves why these patterns of less intense hurricanes are present in the Atlantic and Pacific oceans and why no hurricanes are present at the equator.

Weather Observations We discussed the concept of temperature, which is molecules vibrating by varying intensity to produce what we perceive as temperature. We reviewed the temperature scale and fahrenheit to centigrade conversion table. In terms of wind, we reviewed the conversion of knots to mph.

Sea Surface Temperatures We discussed the correlation between ocean temperature and hurricanes. We viewed a map of the world that displayed the temperature of the ocean and observed that hurricanes tend to occur where the ocean water is warmer. The temperature that best supports hurricanes is 82 degrees Fahrenheit or 28 degrees Centigrade. This can lead researchers to pose the question as to why this happens. Moreover, we related this conclusion of warmer water temperature supporting hurricane development to global warming and what that could possible mean for the future of our planet as it pertains to hurricanes.

Tropical Cyclone Definition We went over the definition of a tropical cyclone, which is listed below and available through a link on the class website.

A cyclone is an atmospheric closed circulation rotating counter­clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.

A tropical depression is a tropical cyclone associated with maximum sustained winds of 38 mph (33 knots) or less.

A tropical storm is a tropical cyclone in which the maximum sustained surface wind speed (using the U.S. 1­minute average) ranges from 34 kt (39 mph or 63 km/hr) to 63 kt (73 mph or 118 km/hr). Usually associated with at least one isobar surrounding the area of lowest pressure at sea level.

A hurricane is a tropical cyclone in which the maximum sustained surface wind (using the U.S. 1­minute average) is 64 kt (74 mph or 119 km/hr) or more. The term hurricane is used for Northern Hemisphere tropical cyclones east of the International Dateline to the Greenwich Meridian. The term typhoon is used for Pacific tropical cyclones north of the Equator west of the International Dateline.

The name is derived from "huracan," a Taino and Carib god, or "hunraken," the Mayan storm god.

Average Rainfall It is usually measured in inches and by centers called a weather station. The weather station contains a can which holds the amount of rain that can be measured manually or automatically. San Francisco’s average rainfall is 25 inches. The lowest measurable rainfall there can be is 0.01 inches which can still cause puddles.

Coordinated Universal Time There are several different time zones across the world, so to make it easier when talking about weather universally we use coordinated universal time or UTC. We went over how to convert universal time to standard local times. For Pacific Standard Time, we subtract 8 hours from UTC. For Pacific Daylight Time, we subtract 7 hours from UTC.

Weather Map Symbols Since there is not enough room on a weather map to spell out full words and there is also a time constraint, we use symbols to represent commonly used words we would see on a weather map. These include rain, drizzle and snow across a scale of how severe the weather condition is. In class, we looked over a handout that showed these weather symbols and then used our knowledge from that to observe the Surface Weather Map of the United States. On this map, we noticed only the one or a few weather stations were represented. This is because if we plotted data from all weather stations, the map would be crowded and difficult to read.