Assignment 1, Spring 2024

Question #1

Please apply the multi-year (> 20 years) monthly mean NCEP/NCAR reanalysis data, plot the vertical-latitudinal distributions of the zonal mean temperature and zonal mean zonal wind of each seasons (at least the winter and summer mean), and briefly describe the features of their spacial distributions and seasonal variations.

请使用多年（>20年）的NCEP/NCAR月平均再分析资料，画出各季节（至少画出冬夏两季）纬向平均温度场、纬向平均纬向风场的高度－纬度剖面分布，并简述其分布特征和季节变化特征。

Question #2

Please apply the multi-year (> 20 years) monthly mean NCEP/NCAR reanalysis data, plot the horizontal distributions of the temperature and zonal wind at 850, 500 and 100 hPa. For temperature, please also plot the horizontal distributions at 1000 hPa. And briefly describe the features of their spacial distributions and seasonal variations.

请使用多年（>20年）的NCEP/NCAR月平均再分析资料，画出各季节（至少画出冬夏两季）温度场、纬向风场在各高度（850、500、100 hPa， 对于温度场请再画出1000hPa）上的水平分布，并简述其分布特征和季节变化特征。

On the netcdf file

Netcdf (Network Common Data Form) is a set of self-describing, machine-independent data formats that support the creation, access, and sharing of array-oriented scientific data. The project homepage is hosted by the Unidata program at the University Corporation for Atmospheric Research (UCAR). They are also the chief source of netCDF software, standards development, updates etc.。 methods to reading netcdf files

Read .nc using Matlab

Since Matlab 2008b ，Matlab offers its own function to read and write .nc files. Here we provide a sample Matlab file to work with dataset stored as .nc files. For figures，Matlab offers multiple formats to save. You can choose the figure format to save from the drop-down of the popup window for figures，or you can use the command “print” to save figures（you may input "help print" for more help). For more info on Matlab, see Matlab website。

Files to download

The dataset used for the homework are the monthly mean data from NCEP-DOE Reanalysis 2, with the time span from 1979/1 to 2009/12. For more info on the dataset, please go to the web. Followings are the data and matlab files that you would need for the homework.

NCEP-DOE monthly mean data of Temperature(1979/1-2009/12): nc file，ReadMe

NCEP-DOE monthly mean data of zonal wind U (1979/1-2009/12): nc file，ReadMe

NCEP-land mask（used to plot the land-sea boundary）: nc file

Matlab files for Questions 1 and 2： matlab file for Q1, matlab file for Q2