Matlab help. Terribly lost, but I know how to access the files I need to load. 1
ID: 3834588 • Letter: M
Question
Matlab help. Terribly lost, but I know how to access the files I need to load.
1. e the island group that you used in homework 4 (see class wiki site if you can't remember and then answer the following with respect that region. For these questions we will look at interannual (ENSO) and decadal (IPCC model forecasts) variability in the region. Define your region to be a box that is 20 by 20 (lon by lat) A. First, make a color-shaded plot of bathymetry. Include a coastline map and colorbar (bathy can be found in SPac-bathy.mat). 10 pts.] B. On a separate figure, make a time-series plot of monthly mean rainfall over the region as measured by satellite to find the month of maximum rain. Next, using the same CMAP data set, make two color-shaded plots of rainfall averaged over the region. Please include a color bar and map. One should be for 1997/98 and one for 1998/99 at the specific month when you have maximum rain. For example, if peak rain occurs in September, make a plot for September 1997 and September 1998. What can you say about potential impacts of El Nino to peak rainfall in the region (assume here that 1997/98 is a typical El Nino and 1998/99 is a normal condition). 10 pts.lExplanation / Answer
1. The Mean Global Temperature has been stable since 1997, despite a continuous increase of the CO2content of the air: how could one say that the increase of the CO2 content of the air is the cause of the increase of the temperature? (discussion: p. 4)
2. 57% of the cumulative anthropic emissions since the beginning of the Industrial revolution have been emitted since 1997, but the temperature has been stable. How to uphold that anthropic CO2 emissions (or anthropic cumulative emissions) cause an increase of the Mean Global Temperature?
[Note 1: since 1880 the only one period where Global Mean Temperature and CO2 content of the air increased simultaneously has been 1978-1997. From 1910 to 1940, the Global Mean Temperature increased at about the same rate as over 1978-1997, while CO2 anthropic emissions were almost negligible. Over 1950-1978 while CO2 anthropic emissions increased rapidly the Global Mean Temperature dropped. From Vostok and other ice cores we know that it’s the increase of the temperature that drives the subsequent increase of the CO2 content of the air, thanks to ocean out-gassing, and not the opposite. The same process is still at work nowadays] (discussion: p. 7)
3. The amount of CO2 of the air from anthropic emissions is today no more than 6% of the total CO2in the air (as shown by the isotopic ratios 13C/12C) instead of the 25% to 30% said by IPCC. (discussion: p. 9)
4. The lifetime of CO2 molecules in the atmosphere is about 5 years instead of the 100 years said by IPCC. (discussion: p. 10)
5. The changes of the Mean Global Temperature are more or less sinusoidal with a well defined 60 year period. We are at a maximum of the sinusoid(s) and hence the next years should be cooler as has been observed after 1950. (discussion: p. 12)
6. The absorption of the radiation from the surface by the CO2 of the air is nearly saturated. Measuring with a spectrometer what is left from the radiation of a broadband infrared source (say a black body heated at 1000°C) after crossing the equivalent of some tens or hundreds of meters of the air, shows that the main CO2 bands (4.3 µm and 15 µm) have been replaced by the emission spectrum of the CO2 which is radiated at the temperature of the trace-gas. (discussion: p. 14)
7. In some geological periods the CO2 content of the air has been up to 20 times today’s content, and there has been no runaway temperature increase! Why would our CO2 emissions have a cataclysmic impact? The laws of Nature are the same whatever the place and the time. (discussion: p. 17)
8. The sea level is increasing by about 1.3 mm/year according to the data of the tide-gauges (after correction of the emergence or subsidence of the rock to which the tide gauge is attached, nowadays precisely known thanks to high precision GPS instrumentation); no acceleration has been observed during the last decades; the raw measurements at Brest since 1846 and at Marseille since the 1880s are slightly less than 1.3 mm/year. (discussion: p. 18)
9. The “hot spot” in the inter-tropical high troposphere is, according to all “models” and to the IPCC reports, the indubitable proof of the water vapour feedback amplification of the warming: it has not been observed and does not exist. (discussion: p. 20)
10. The water vapour content of the air has been roughly constant since more than 50 years but the humidity of the upper layers of the troposphere has been decreasing: the IPCC foretold the opposite to assert its “positive water vapour feedback” with increasing CO2. The observed “feedback” is negative. (discussion: p.22)