Data accompanying the research on Seasonal modulation of Arctic M2 tide

Bij de Vaate, I.; Vasulkar, A. N.; Slobbe, D. C.; Verlaan, M.


The dataset constists of two files with data obtained in a study on the influence of Arctic fast ice on the seasonal modulation of the m2 tide. 


- ModM2Arctic_altimetry.nc
This file contains M2 amplitude and phases and the magnitude of their seasonal modulation as computed from SAR altimetry-derived water levels. 
Data was obtained from the two high-inclinations satellite missions: CryoSat-2 (2011-2019) and Sentinel-3 (2016-2019). Obtained water levels were 
stacked on a 3 by 1 degree grid, before tidal harmonic analysis was performed with the software UTide.

Variables in the file:
lat, lon		coordinates of the weighted center of each grid cell
Ampl_mean		(yearly) average M2 amplitude [m]
Ampl_sept		average M2 amplitude in September [m]
Ampl_march		average M2 amplitude in March [m]
Ampl_modulation		magnitude of seasonal modulation of M2 amplitude (yearly max-min) [m]
Phase_mean		(yearly) average M2 phase [degree]
Phase_sept		average M2 phase in September [degree]
Phase_march		average M2 phase in March [degree]
Phase_modulation	magnitude of seasonal modulation of M2 phase (yearly max-min) [degree]


- ModM2Arctic_gtsmF.nc
This file contains March and September M2 amplitudes and phases as derived from the Global Tides and Surge Model (using the fine grid: resolution varies from 1.25 to 25 km) that is forced by a seasonally varying fast ice cover. 
The latter was done for 2013 and 2017, years with respectively the maximum and minimum fast ice cover within the time span of the considered SAR data. Monthly amplitudes
and phases were obtained from the modelled water levels with the use of UTide.

Variables in the file:
lat, lon		coordinates of the weighted center of each grid cell (same as in ModM2Arctic_altimetry.nc)
Ampl_sept		model-derived M2 amplitude in September, with no fast ice cover [m]
Ampl_march_2013		model-derived M2 amplitude in March, using fast ice cover of March, 2013 [m]
Ampl_march_2017		model-derived M2 amplitude in March, using fast ice cover of March, 2017 [m]
Phase_sept		model-derived M2 phase in September, with no fast ice cover [degree]
Phase_march_2013	model-derived M2 phase in March, using fast ice cover of March, 2013 [degree]
Phase_march_2017	model-derived M2 phase in March, using fast ice cover of March, 2017 [degree]
