Calculate the t-test statistic for a two-sample difference of means test and 
shade the grid cells that are significant at a chosen level. 
We assume the population variances are equal.

Degrees of freedom: df = n1 + n2 -2, 
where n1 is the size of the first sample and n2 is the size of the second sample.
n1 = 14; number of AMS or JAS in years from 1980 to 1993
n2 = 14; number of AMS or JAS in years from 1994 to 2007
df = 26
Significance level: .05 (95%)
Cutoff t (crtical value) = 2.056 ;


*N+DCHL_mgm3_t-test_AMJ_JAS_yr94_07:80_93_nof56N.eps

t-test statistic for the 1st sample depth-averaged (top 0-30m and 30-60m)
NCHL+DCHL for AMJ or JAS from 1980 to 1993 and the second sample NCHL+DCHL 
for AMJ or JAS from 1994 to 2007
The grid cells that are significant at a chosen level (.05) are shaded


*N+DCHL_mgm2_t-test_AMJ_JAS_yr94_07:80_93_nof56N.eps

t-test statistic for the 1st sample depth-integrated (top 0-30m and 30-60m)
NCHL+DCHL for AMJ or JAS from 1980 to 1993 and the second sample NCHL+DCHL 
for AMJ or JAS from 1994 to 2007
The grid cells that are significant at a chosen level (.05) are shaded


*Temp_t-test_AMJ_JAS_yr94_07:80_93_nof56N.eps

t-test statistic for the 1st sample depth-averaged (top 0-10m and 0-30m)
temperature for AMJ or JAS from 1980 to 1993 and the second sample temperature
for AMJ or JAS from 1994 to 2007
The grid cells that are significant at a chosen level (.05) are shaded


*Salt_t-test_AMJ_JAS_yr94_07:80_93_nof56N.eps

t-test statistic for the 1st sample depth-averaged (top 0-30m and 30-60m)
salinity for AMJ or JAS from 1980 to 1993 and the second sample salinity
for AMJ or JAS from 1994 to 2007
The grid cells that are significant at a chosen level (.05) are shaded


*SeaIce_t-test_Arc_AMJ_JAS_yr94_07:80_93_nof56N.eps

t-test statistic for the 1st sample sea-ice concentration for AMJ or JAS from 
1980 to 1993 and the second sample sea-ice concentration  for AMJ or JAS from 
1994 to 2007
The grid cells that are significant at a chosen level (.05) are shaded


*MLD_t-test_AMJ_JAS_yr94_07:80_93_nof56N.eps

t-test statistic for the 1st sample MLD for AMJ or JAS from 
1980 to 1993 and the second sample MLD for AMJ or JAS from 1994 to 2007
The grid cells that are significant at a chosen level (.05) are shaded


*WindSpeed10m_t-test_Arc_AMJ_JAS_yr94_07:80_93_nof56N.eps

t-test statistic for the 1st sample wind speed at 10m for AMJ or JAS 
from 1980 to 1993 and the second sample wind speed at 10m for AMJ or JAS from 
1994 to 2007
The grid cells that are significant at a chosen level (.05) are shaded


*Htcont300m_t-test_Arc_AMJ_JAS_yr94_07:80_93_nof56N.eps

t-test statistic for the 1st sample heat content (top 0-300m) for AMJ or JAS 
from 1980 to 1993 and the second sample heat content (top 0-300m) for AMJ 
or JAS from 1994 to 2007
The grid cells that are significant at a chosen level (.05) are shaded


*SWRad_t-test_Arc_AMJ_JAS_yr94_07:80_93_nof56N.eps

t-test statistic for the 1st sample shortwave radiation for AMJ or JAS 
from 1980 to 1993 and the second sample shortwave radiation for AMJ 
or JAS from 1994 to 2007
The grid cells that are significant at a chosen level (.05) are shaded


*NetDwnHtFlx_t-test_AMJ_JAS_yr94_07:80_93_nof56N.eps

t-test statistic for the 1st sample downward heatf flux for AMJ or JAS 
from 1980 to 1993 and the second sample downward heat flux  for AMJ 
or JAS from 1994 to 2007
The grid cells that are significant at a chosen level (.05) are shaded


*NO3_Arc_t-test_AMJ_JAS_yr94_07:80_93_nof56N.eps

t-test statistic for the 1st sample depth-averaged (top 0-30m and 30-60m) NO3 
for AMJ or JAS from 1980 to 1993 and the second sample depth-averaged NO3 
for AMJ or JAS from 1994 to 2007
The grid cells that are significant at a chosen level (.05) are shaded


*Fer_t-test_AMJ_JAS_yr94_07:80_93_nof56N.eps

t-test statistic for the 1st sample depth-averaged (top 0-30m) Fe 
for AMJ or JAS from 1980 to 1993 and the second sample depth-averaged Fe 
for AMJ or JAS from 1994 to 2007
The grid cells that are significant at a chosen level (.05) are shaded