Below is a list of proposed, self guided exercises. I generally tried to order the exercises by increasing complexity. While none of them is really challenging, the various exercises aim to give you with first hand experience with the data sets and tools discussed over the course of the IAP activity. Here it is assumed that you have completed the set up of the activities as explained in guidelines/iap-idma-instructions. tips : - look for answers/examples in the programs we ran together in class #1 and #2 - type ‘help read_nctiles’ in matlab and similarly for all other functions - use the matlab debugger to go through computations step by step Argo profile data exercises: ———————————— 1) modify idma_float_plot.m to display salinity rather than temperature records 2) starting from the output of idma_float_plot.m (“p”) interpolate the data to daily values, the apply convn to filter out sub-monthly fluctuations tip : use 30 days as the practical definition of “monthly” 3) extract all profiles from argo_feb2013_2008_to_2010_model.nc that are located in the box defined by 10N-30N and 180W-120W tip : use MITprof_subset in analogy with idma_float_plot.m 4) compute 12 monthly mean temperature profiles for one float (“p”) or for all profiles in the 10N-30N and 180W-120W box (see exercise #2). tip: get profiles’ month from the prof_date or prof_YYYYMMDD fields 5) compute normalized model-data differences d=(p.prof_Testim-p.prof_T).*sqrt(p.prof_Tweight) then compute its # of entries for each depth level, and plot its histogram for a chosen level 6) compute vertical gradients of temperature profiles, compute temperature anomalies from the same profiles, and combine the two to infer vertical displacements of isotherms. ECCO/gcmfaces exercises: ———————————— 1) modify example_transports.m to compute the oceanic mass transport between Boston and Paris using gcmfaces_lines_transp.m and calc_transports.m 2) identify the Surface Height Anomaly variable from the files in nctiles_climatology, read its series of monthly fields into memory using read_nctiles.m, and display its temporal standard deviation 3) identify the grid cell area and land mask variables in mygrid, load the ETAN monthly time series, and compute the area weighted average of monthly Surface Height Anomaly between 10E and 10W 4) load the UVELMASS and VVELMASS variables, compute the global overturning stream function for each month, and display its evolution at 25N 5) load the UVELMASS and VVELMASS variables, extract one vertical level, then compute its zonal and meridional components, divergence and rotational tip : routines that do such computations are located in gcmfaces_calc/ with examples in gcmfaces_diags/diags_set_*.m 6) modify example_smooth.m to apply the diffusive smoother to the following field : unity at one point, zeros everywhere else, NaN over land. Run this computation via the matlab debugger and visualize the intermediate operations (gradients, flux convergence, exchanges, etc.). MITgcm exercises: ————————— 1) increase experiment duration for adjustment.cs-32x32x1, tutorial_held_suarez_cs, and tutorial_plume_on_slope by editing their respective input/data as follows: - tutorial_held_suarez_cs/input/data: < nTimeSteps=16, > nTimeSteps=69120, - tutorial_plume_on_slope/input/data: < nTimeSteps=20, > nTimeSteps=8640, - adjustment.cs-32x32x1/input/data: < nTimeSteps=24, > endTime=172800., 2) compile and run the experiments using testreport using the command ./testreport -fast -t tutorial_plume_on_slope and accordingly for the other two. Note: the -fast option activates compiler optimization, which accelerates the runs greatly. notes : - to learn more about testreport type 'testreport --help' or see mitgcm.org/public/devel_HOWTO/devel_HOWTO.pdf - 'testreport -clean' is useful to reset an experiment. - testreport links the various inputs in the 'run/' subdirectory and then automatically runs the model ('mitgcmuv'). As long as you do not empty 'run/' then you can exectute the model directly using this command: './mitgcmuv > output.txt'. 4) use the mitgcm_plot_adju_cs32.m, mitgcm_plot_held_suarez.m, and mitgcm_plot_plume.m (http://mitgcm.org/viewvc/MITgcm/MITgcm_contrib/gael/comm/course-idma2016/matlab/) to display results (type e.g. 'help mitgcm_plot_adju_cs32' first). notes: this assumes that gcmfaces has been installed and added to the Matlab path as explained at the beginning of idma2016-instructions.pdf