[海洋物理]有人能救救我嗎？？.........（急件）

njiu3

Introduction to physical oceanography term report
1.Coriolis force seems like a very small force, but is it really that small if friction can be ignored? Consider a one kilogram parcel of water moving to the east at 20cm/s at30°N Latitude:
。  What is the magnitude of the coriolis force acting on the parcel?
。  What is the direction of the force?
。  If a force of this magnitude acts on a one kilogram parcel of water that is initially at rest, what is the velocity of the parcel after one hour?
2. What is meant by an anomaly? For example, what is meant by the ”anomaly of sea-surface temperature” such as shown in figure 6.3 of the notes? Now, go to the Climate Diagnostics Bulletin （http://www.cpc.ncep.noaa.gov/products/analysis_moni
toring/bulletin/index.html）and print the map of sea-surface temperature anomalies at Tropical Strip SST（http://www.cpc.ncep.noss.gov/products/analysis_monoitoring/bull
etin/figt18.gif）（Figure T18）. The most recent weekly map of NOAA optimum interpolation Sea Surface Temperature Analysis（http://www.emc.ncep.noaa.gov/resea
rch/cmb/sst_analysis/images/tpacv2.gif）.
。 Where are the largest positive and negative anomalies?
。 How large are the anomalies?
。 Looking at the map, estimate what accuracy temperature measurements must have if they are to be used to make such a map.
。 Are the sea-surface temperature measurements made by the AVHRR sufficiently accurate that the data can be used to produce anomaly maps without using ship reports of sea-surface temperature?
3.  Ekman pumping: Go to the NOAA pacific Marine Environmental Laboratory Live Access to climate data at http://ferret.pmel.noaa.gov/NVODS/servlets/dataset?
Catitem =3419. Go to the COADS Monthly Climatology in the left column, go to wind vectors, and download the January map.
。  On the map, carefully sketch the Ekman transports driven by the winds in the North Atlantic.
。  Where in the North Atlantic do you expect to find a dome of warm water produced of the ocean dome? For more information, see the tutorial on ocean gyres at the Rosensteil School of marine and Atmospheric Sciences（http://oceancurrents.r smas.Miami.edu/ocean-gyres.html）.
4. You are planning a vacation to the beach. You decide to go to the southern hemisphere for a change in pace. You also decide to go to a beach near 25°S because you know that the descending air of the Hadley circulation in the atmosphere leads to clear sunny skies at this latitude.
。  Look at a map of mean sea surface temperature of the ocean at 25°S at the east and west coasts of the three southern-hemisphere continents. What are the values of temperature?
。  What is the temperature difference between the east and west coasts of each continent at this latitude?
。  Describe at least two processes that might cause the difference in temperature? Hint: You may wish to use information in Fig. 4.2 to argue your case.
。  Do you want to vacation at an East or West coast?
5. The wind at 45°N in the North Pacific was observed to suddenly begin blowing at 15m/s from270°, a strong west wind. At this location and time:
。  What is the wind stress?
。  What is the horizontal force produced by the atmosphere on one square meter of the sea surface?
。  What is the horizontal force produced by the ocean on one square meter ate base of the atmosphere（force on the air just above the sea surface?）
。  How long would it take the wind to accelerate water in the mixed layer to a speed on 0.2m/s , ignoring for this problem the influence of the coriolis force, and assuming that the mixed layer responds as a slab, that the mixed layer is 20m deep, and that the water below the mixed layer is not influenced by the wind?
6. We saw earlier that changes in density of the ocean are small. Now let’s look at the implication for determining the depth of an isobaric surface.
。  Calculate the change in depth of the 1000 decibar pressure surface if the mean density of the water column changes by0.05kg/m3. Give the change in depth in meters.
。  Can the change in depth of the pressure surface be measured directly? That is, can it be determined using pressure measurements?
7. Lets now look at the same problem for the atmosphere.
。  Look at a daily weather map, such as the map in the daily paper.
。  What are typical changes in pressure at a fixed level, say the surface?
。  Now convert the change in pressure at a fixed height to change in height of an isobaric surface so you can compare your result to your result in problem 1 above. To do this, use the density of air at the surface, assume that air density is constant in the lower few hundred meters of the atmosphere（it isn’t but adding the change makes the computation needlessly difficult）, and calculate the distance from the surface to some isobaric surface of your choice.
。  Can the change in height be measured directly, say by using some instrument to measure vertical elevation?
8. A satellite altimeter observed that sea level relative to the geoid（the oceanictopography） increased by 1.0m over a distance of 200km as the satellite track crossed a current at 35°N.
。  If the satellite track is northwest-southeast, and if sea level increases toward the southeast, what can you say about the velocity（magnitude and direction）of the surface geostrophic current?
。  Please give a quantitative answer.
9. The average density from the surface to a depth of 2000 decibars at hydrographic station A in the North Atlantic near 35°N was observed to be 1027kg/m3.At station B, 250km northwest of station A, the average water density from the surface to a depth of 2000 decibars was observed to be 1027.80kg/m3.
。  What is the slpoe of the sea surface midway between A and B assuming the slope is constant between the two stations and that the 2000 decibar surface is a level surface?（Use g =9.800m/s）
。  What is the velocity of the surface geostrophic current calculated from this hydrographic data?
10. Combine the information in questions 1 and 2 and calculate the velocity at 2000 decibars perpendicular to the line between A and B.
。  What is the speed and direction of the current?
。  Why does the current differ from what you assumed in problem 2?
11. Using the information above,
。  Which station has warmer water?
。  Looking downstream at a point midway between A and B, what is the direction to warm water?
12.The Gulf Stream and Kuroshio both leave the coast near 40°N latitude. Why? Hint: It has to do with Sverdrup circulation and the idea that the streamlines of the Sverdrup circulation are closed at a western boundary by a western boundary current.