545463.fig.002a
(a)
545463.fig.002b
(b)
545463.fig.002c
(c)
545463.fig.002d
(d)
Figure 2: NH winter (JFM) NAO positive-NAO negative cyclone track frequency composite for (a) NCEP1_5801, (b) like (a) but for ERA40_5801. Units: no. of cyclones per 5° Lat 5° Lon box. Hatched areas are significant at 90% for 2-tailed -test. (c) NH winter (JFM) NAO positive-NAO negative cyclone track intensity composite for NCEP1_5801. (d) like (c) but for ERA40_5801. Units: hPa. Hatched areas are significant at 90% for 2-tailed -test.