The A2 Scenario

The distribution of changes in P in the Arctic along with its warming is, according to this scenario, similar to that discussed above. The greatest conformity may be noted in ATLR, whereas the least occurs in CANR (Table 7.3), Because of the employment in this scenario of the differences in P taken from the sets of consecutive years, it is more reliable than the A1 scenario. That is why the results of the calculations have also been presented in graphic form (Figures 7.2 and 7.4). The shaded areas indicate places where a decrease in P is expected. In winter it will occur in the greater part of the Arctic, with a clear maximum (exceeding 100 mm) around the southern coasts of Greenland. Other areas with a considerable decrease in P (reaching 40 mm) are expected to be the south-eastern parts of the Barents Sea and the south of Novaya Zemlya. On the other hand, more considerable increases in P will only be observed in the area stretching from the north-eastern coast of Greenland to Jan Mayen, in the eastern part of Kara Sea, and in the south-western part of the Taymyr Peninsula. In spring the situation resembles that in winter to a great extent (Figure 7.4). As far as the differences are concerned, it is worth stressing that in this season the areas with the greatest decrease in P will be located in SIBR, PACR, and CANR, whereas an increase will occur on the southern foreland ofGreenland. It is worth mentioning that changes in P over half the area of the Arctic will exceed just as in winter (Table 7.3). In summer the distribution of changes in P is considerably different to that occurring in spring and in winter. A decrease in P should occur around Greenland and throughout almost the whole area of ATLR, with the exception of the extreme eastern parts of ATLSRe and in the greater part of the Canadian Arctic (Figure 7.4). However, the scale of this decrease will be negligible (mostly < 0.5(7) reaching ca. 30 mm maximum. The remaining parts of the Arctic are characterised by more significant changes in P

although their absolute values are similar. In autumn, along with the warming of the Arctic, the least significant changes in P will occur (Table 7.3, Figure 7.4). Out of all the seasons, it is in autumn when the rise in P will be observed in the greatest area, still generally not exceeding 10 mm, with the exception of the western part of ATLSRs and the eastern part of ATLSRe, where it may reach ca. 30 mm maximum. A decrease in P is expected in ATLSRs (in its eastern part), in ATLSRn, in BAFR, and in the greater part of PACR and CANSRs.

The A2 scenario for annual sums shows that, along with warming, there will be a rise in P over roughly half the area of the Arctic, while a decrease in P will be noted in the other half. The mean P in the Arctic should, however, decrease, because the scale of its decreases is greater than that of its increases. On the basis of the data presented in Figure 7.2 it can be seen that its lower values will occur virtually over the whole area of ATLR, in the western part of CANR, and in the south of BAFR. The most significant decreases (> lo) will occur on the southern coasts of Greenland and in the southern part of the Barents Sea (Table 7.3). The greatest humidity, along with warming, should occur in the eastern part of ATLSRe and in the greater part of the Taymyr Peninsula, where an increase in P may reach over 100 mm, constituting more than The other area where its rise is significant is the northern part of BAFR and the eastern CANSRs.

Figure 7.4. Scenarios of changes in the seasonal totals of P (in mm) in the Arctic. Scenario A2. Areas with a decrease in P are hatched.

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