zzzElizabethWong-MatlabResults

**1. Download and read**
My language code file for making the below figures is linked here **[|HW1.m]** __.__ I started from scratch.

===**2. Calculate zonally averaged P and v over longitude, and plot the resulting latitude-time series.** ===

Here is the latitude-time sections of P in the zonal mean, and at 91.25W: It could be seen that at 90W the precipitation rates is quite different from the global average precipitation over the months. The maximum precipitation rates are constantly North of the equator at 90W while the global average has maximum rates at the North of the equator during the summer months and South of the equator during the winter months. It is also noted that the mean precipitation occurs near the ITCZ at the tropics where all the monsoons generally occur

Here is the latitude-time sections of v in the zonal mean, and at 90W: The meridional wind speed at 90W and the global mean is also different. Generally the maximum wind speed occurs during the months of June/July/August for the global average, but shifted slightly to the later months of August/Sep/Nov at 90W (spring). The magnitude of the winds are also much greater in 90W due to the ITCZ in the upper part of the equator and polar winds in the lower part of the equator.

===**3. Average air temperature over both lat and lon, to make a 12-month time series. Which season has the warmest global mean surface temperature? Can you understand why?** ===

Global mean surface temperature has a mild annual cycle: Months of June/July/August have the warmest global mean surface temperature (summer months in Northern Hemisphere). This is due to the fact that the Northern Hemisphere has more land mass than the Southern Hemisphere, thus allowing more heat to be absorbed during July which is when the Northern Hemisphere receives maximum solar insolation from the sun. It is also noted that this deviation is small, only about 3 degC.

===**4. Make a map of the temporal (i.e. seasonal) standard deviation of precipitation, expressed as a percentage of the annual mean precipitation. This might be one definition of a "monsoonal" climate.** ===

Here is a map expressing the seasonality of precipitation: Places with intensely seasonal rainfall tend to be in the tropics (the asian monsoon regions, saharan desert), Northern Australia, west coast of Mexico. M_Map was used to map this.

===**5. What is the space-time standard deviation of 'air' (temperature)?** === The total space-time standard deviation of temperature is 15.2__.__ The challenge of computing it is that we want area averages over the Earth, but we started with lat-lon grids. A simple call of stdev(air array) gives a much larger value which is incorrect due to the fact that the earth is a sphere. (The poles are weighted more than at the equator.) To correct this, we use a weighted average over latitude with coslat, thus yielding the answer of 15.2

=**Extra credit / extensions of the basic assignment:** =