Abstract. The local weather and climate of the Himalayas are sensitive and interlinked with
global-scale changes in climate, as the hydrology of this region is mainly
governed by snow and glaciers. There are clear and strong indicators of
climate change reported for the Himalayas, particularly the Jammu and Kashmir
region situated in the western Himalayas. In this study, using observational
data, detailed characteristics of long- and short-term as well as localized
variations in temperature and precipitation are analyzed for these six
meteorological stations, namely, Gulmarg, Pahalgam, Kokarnag, Qazigund,
Kupwara and Srinagar during 1980–2016. All of these stations are located in Jammu and Kashmir,
India. In
addition to analysis of stations observations, we also utilized the dynamical
downscaled simulations of WRF model and ERA-Interim (ERA-I) data for the
study period. The annual and seasonal temperature and precipitation changes
were analyzed by carrying out Mann–Kendall, linear
regression, cumulative deviation and Student's t statistical tests. The results show an
increase of 0.8 ∘C in average annual temperature over 37 years (from 1980 to 2016) with higher increase in maximum temperature
(0.97 ∘C) compared to minimum temperature (0.76 ∘C).
Analyses of annual mean temperature at all the stations reveal that the
high-altitude stations of Pahalgam (1.13 ∘C) and Gulmarg
(1.04 ∘C) exhibit a steep increase and statistically significant
trends. The overall precipitation and temperature patterns in the valley show
significant decreases and increases in the annual rainfall and temperature
respectively. Seasonal analyses show significant increasing trends in the
winter and spring temperatures at all stations, with prominent decreases in
spring precipitation. In the present study, the observed long-term trends in
temperature (∘Cyear-1)
and precipitation (mm year−1) along with their
respective standard errors during 1980–2016 are as follows: (i) 0.05 (0.01)
and −16.7 (6.3) for Gulmarg, (ii) 0.04 (0.01) and −6.6 (2.9) for Srinagar, (iii) 0.04 (0.01)
and −0.69 (4.79) for Kokarnag, (iv) 0.04 (0.01) and −0.13 (3.95)
for Pahalgam, (v) 0.034 (0.01) and −5.5 (3.6) for Kupwara, and (vi) 0.01 (0.01)
and −7.96 (4.5) for Qazigund. The present study also reveals that variation
in temperature and precipitation during winter (December–March) has a close
association with the North Atlantic Oscillation (NAO). Further, the observed
temperature data (monthly averaged data for 1980–2016) at all the stations
show a good correlation of 0.86 with the results of WRF and therefore the model
downscaled simulations are considered a valid scientific tool for the
studies of climate change in this region. Though the correlation between WRF
model and observed precipitation is significantly strong, the WRF model
significantly underestimates the rainfall amount, which necessitates the need
for the sensitivity study of the model using the various microphysical
parameterization schemes. The potential vorticities in the upper
troposphere are obtained from ERA-I over the Jammu and Kashmir region and
indicate that the extreme weather event of September 2014 occurred due to
breaking of intense atmospheric Rossby wave activity over Kashmir. As the
wave could transport a large amount of water vapor from both the Bay of
Bengal and Arabian Sea and dump them over the Kashmir region through wave
breaking, it probably resulted in the historical devastating flooding of
the whole Kashmir valley in the first week of September 2014. This was
accompanied by extreme rainfall events measuring more than 620 mm in some
parts of the Pir Panjal range in the south Kashmir.
A spatial approach to rainfall in Sertão do Pajeú – Pernambuco
