Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Journal 11/15/16 Why might we care if the sun’s surface is getting a little more violent? Objective Tonight’s Homework To learn about activity on the surface of the sun Read 16.1 and 16.4 (pp 386 387, 396 - 401) Sunspots Like many planets, the sun has a magnetic field (from metallic hydrogen). Unlike the planets, though, the sun’s magnetic field doesn’t have just one north and south pole, but millions. This extremely complex field has several results. Sunspots The visible evidence of the sun’s magnetic field are the sunspots. These spots are roughly the size of the Earth and are indications of places where the magnetic field has become twisted. Their appearance comes from the fact that they are about 1,000 K cooler than the regions of the sun around them. Sunspots Sunspots form as the sun’s magnetic field becomes twisted, as illustrated in this picture. Sunspots Sunspots Sunspots are noted for appearing in certain latitudes as well. The more sunspots visible on the sun, the more positive and negative the latitudes will be. At their most extreme, sunspots will reach as far as 60 N or 60 S, but never farther. Sunspots So why do we care about sunspots? They indicate more violent activity on the sun. The more sunspots the sun has, the more likely a violent outburst could happen in the direction of Earth. We call these outbursts “Coronal Mass Ejections” and they can cause huge amounts of damage to our electronic systems and satellites. We’ll study these later in more detail. Sunspots Sunspots also appear and disappear in numerical patterns. Every certain number of years, the number of sunspots increases dramatically, then a few years later falls off again. We call the high point of this cycle the “solar maximum”. The low point is called the “solar minimum”. We’ll look at this more in detail later, but we have data reaching back on sunspots to the mid 1600s so the patterns we know are very established. Graphing Sunspots It’s been of interest for scientists to note how many sunspots appear each year so we can discover if there’s an underlying nature of the sun for us to discover. We’re going to replicate this activity a bit. Each of you is going to graph a span of real sunspot data. We’ll then put the data together and see what patterns we find. Pick a set of data on the next slide and start graphing it with bar graphs. We’ll continue this activity both today and tomorrow. Graphing Sunspots Year # of spots Year # of spots Year # of spots Year # of spots 1955 38 1970 104.5 1985 17.9 2000 119 1956 141.7 1971 66.6 1986 13.4 2001 110.9 1957 190.2 1972 68.9 1987 29.4 2002 104 1958 184.8 1973 38 1988 100.2 2003 63.7 1959 159 1974 34.5 1989 157.6 2004 40.4 1960 112.3 1975 15.5 1990 142.2 2005 29.8 1961 53.9 1976 12.6 1991 145.8 2006 15.2 1962 37.6 1977 27.5 1992 94.5 2007 7.5 1963 27.9 1978 92.5 1993 54.7 2008 2.9 1964 10.2 1979 155.4 1994 29.9 2009 3.1 1965 15.1 1980 154.6 1995 17.9 2010 1966 47 1981 140.4 1996 8.6 2011 16.5 55.6 1967 93.8 1982 115.9 1997 21.5 2012 57.6 1968 105.9 1983 66.6 1998 64.3 2013 64.7 1969 105.5 1984 45.9 1999 93.3 2014 79.3 Exit Question What would we see if the sun had a stronger magnetic field? a) more sunspots b) Less sunspots c) Same number but in different location d) One big sunspot e) No difference