Climate change and spatio-temporal trend analysis of climate extremes in the homogeneous climatic zones of Pakistan during 1962-2019

trend. The comparison of these three decades for maximum temperature is shown in Table 7. In JJA, the maximum temperature has a decreasing trend during 1990–1999 except Gilgit and during 2000–2009 at Gopis. The trend during 2010–2019 changed and increased in most of the stations except Gilgit with insignificant decreasing trend in JJA. Minimum temperature shows increasing trend in some parts (Bunji and Gilgit) and decreasing trend in others (Gopis and Skardu) during 1990–1999 and 2000–2009 as shown in Table 8. In contrast, during 2010–2019, minimum temperature shows increasing trend at these stations. These results show conflicting signals in climate. In the most recent decade of 2010–2019, precipitation decreased in DJF and temperature (maximum and minimum) increased in JJA. It is interesting to see a consistently decreasing trend in the SON in temperature (maximum and minimum) considering the overall thirty years period (1991–2019). The station-wise climate extremes in the northern Pakistan are shown in Fig 11. The results show that SU25 increased throughout except Skardu during 1991–2019. TN10P (cold nights) decreased significantly at some of the stations located in the Northern Paki- stan during 1991–2019. TN90P (warm nights), TX10P (cold days) TR20 (tropical nights) have decreasing trend during 1991–2019 in most parts of this region. TX90P (warm days) has mixed trend, decreasing at Darosh, Gilgit and Skardu and increasing trend at the remaining stations. Table 5. Station and seasonal wise results of MK test and their statistical significance for precipitation, maximum

and minimum temperature during the 1962–1990. Station DJF MAM JJA SON Kendall τ P-Value Kendall τ P-Value Kendall τ P-Value Kendall τ P-Value Precipitation (1962–1990) Astore 3.87e-02 0.011 1.63e-02 0.270 3.64e-02 0.020 Bunji 1.18e-02 0.461 5.91e-02 0.000 7.03e-02 6.82e-06 1.72e-02 0.280 Chilas 8.60e-02 5.44e-08 5.68e-02 0.000 8.49e-02 4.58e-08 5.79e-02 0.000 Darosh 1.54e-02 0.308 -5.37e-02 0.000 2.28e-02 0.136 -1.95e-02 0.204 Gilgit 4.34e-02 0.007 3.67e-02 0.017 7.05e-02 8.89e-06 Gopis -6.32e-02 7.60e-05 -1.14e-01 1.95e-13 -8.49e-02 6.16e-08 -1.19e-01 8.97e-14 Skardu 5.05e-02 0.001 2.67e-02 0.083 9.11e-02 5.33e-09 2.02e-02 0.205 Maximum Temperature (1962–1990) Astore -4.38e-02 0.001 3.42e-02 0.009 -6.06e-03 0.648 2.72e-03 0.838 Bunji 1.98e-02 0.140 2.75e-02 0.036 -8.89e-02 1.88e-11 -1.74e-02 0.188 Chilas 9.25e-03 0.490 3.76e-02 0.004 -3.13e-02 0.02 -6.33e-03 0.634 Darosh -4.00e-02 0.003 6.11e-02 3.72e-06 -1.81e-02 0.173 -4.18e-02 0.002 Gilgit 6.74e-03 0.616 4.05e-02 0.002 -3.68e-02 0.005 -4.51e-03 0.734 Gopis 3.04e-02 0.023 5.77e-02 1.25e-05 -3.99e-02 0.002 -4.11e-02 0.002 Skardu 7.84e-02 4.73e-09 8.59e-02 7.90e-11 3.49e-02 0.008 3.49e-02 0.008 Minimum Temperature (1962–1990) Astore 1.23e-02 0.357 7.00e-02 1.28e-07 -2.93e-02 0.027 -3.48e-02 0.009 Bunji -1.43e-01 2.2e-16 -5.93e-02 7.69e-06 -1.70e-01 2.2e-16 -1.57e-01 2.2e-16 Chilas -5.26e-02 8.52e-05 4.24e-02 0.001 -4.98e-02 0.000 -4.22e-02 0.001

Darosh -1.06e-01 2.68e-15 -3.04e-03 0.818 -1.11e-01 2.2e-16 -8.56e-02 1.20e-10 Gilgit 5.03e-03 0.704 -3.74e-02 0.005 -4.54e-02 0.000 Gopis 1.68e-02 0.21 5.08e-02 0.000 -6.19e-02 3.08e-06 -8.87e-02 2.53e-11 Skardu 6.14e-02 4.46e-06 -6.95e-03 0.600 -7.90e-02 2.78e-09 -5.60e-02 2.45e-05 https://doi.org/10.1371/journal.pone.0271626.t005 PLOS ONE Climate change and extremes analysis using observed data (1962-2019) over Pakistan PLOS ONE | https://doi.org/10.1371/journal.pone.0271626 July 27, 2022 17 / 27