and minimum temperature during the pre-monsoon and
monsoon seasons in South India during 1950–2005 are
assessed to be detectably different from natural internal climate variability, and these temperature changes are attributed with confidence to climate change induced by
anthropogenic effects (Sonali et al. 2018). These assessments
are based on detection and attribution studies using observational datasets and the multiple atmosphere–ocean coupled general circulation model (AOGCM) outputs of
historical simulation experiments conducted in the fifth
phase of the Coupled Model Intercomparison Project
(CMIP5; Taylor et al. 2012), from which human and natural
causes of climate change could be identified and quantified.
2.2.3 Temperature Extremes
The all India averaged annual frequency of warm days and
nights have increased, and cold days and nights have
decreased since 1951 (Fig. 2.6 and Table 2.4). These
extreme temperature indices are defined from daily temperatures as days when daily maximum (daytime) and miniFig. 2.5 Time-series of all India
averaged annual (left panels)
specific humidity and (right
panels) relative humidity from
(top panels) HadISDH dataset and
(bottom panels) ERA-Interim
reanalysis for the period 1979–
2015. The dashed blue lines
indicate the linear trend for the
period 1979–2015. The rate of
change during this period is
shown below the trend line. The
90% confidence intervals for
these trend estimates are assessed
in Table 2.3
Table 2.3 Observed changes in
India land mean annual and
seasonal surface specific humidity
and relative humidity between
1979 and 2015
Season
Specific humidity trends 1979–
2015 (g kg
−1 per decade)
Relative humidity trends 1979–
2015 (% per decade)
HadISDH
ERA-interim
HadISDH
ERA-interim
Annual
0.27
*
± 0.13
0.27
*
± 0.07
0.69
*
± 0.48
0.65
*
± 0.40
Winter (Dec–Feb)
0.20
*
± 0.10
0.20
*
± 0.10
0.86
*
± 0.54
0.75
*
± 0.60
Pre-monsoon (Mar–May)
0.37
*
± 0.11
0.36
*
± 0.11
0.79
*
± 0.58
0.85
*
± 0.64
Monsoon (Jun–Sep)
0.22
*
± 0.11
0.25
*
± 0.09
0.47 ± 0.60
0.45 ± 0.51
Post-monsoon (Oct–Nov)
0.33
*
± 0.25
0.37
*
± 0.16
1.00 ± 1.08
0.86
*
± 0.79
Estimates are derived from the HadISDH dataset and ERA-Interim reanalysis. Trends and significance have
been calculated as in Table 2.1. Bold values with star sign (*) indicate that trend is significant (i.e. a trend of
zero lies outside the 90% confidence interval)
2 Temperature Changes in India
27
monsoon seasons in South India during 1950–2005 are
assessed to be detectably different from natural internal climate variability, and these temperature changes are attributed with confidence to climate change induced by
anthropogenic effects (Sonali et al. 2018). These assessments
are based on detection and attribution studies using observational datasets and the multiple atmosphere–ocean coupled general circulation model (AOGCM) outputs of
historical simulation experiments conducted in the fifth
phase of the Coupled Model Intercomparison Project
(CMIP5; Taylor et al. 2012), from which human and natural
causes of climate change could be identified and quantified.
2.2.3 Temperature Extremes
The all India averaged annual frequency of warm days and
nights have increased, and cold days and nights have
decreased since 1951 (Fig. 2.6 and Table 2.4). These
extreme temperature indices are defined from daily temperatures as days when daily maximum (daytime) and miniFig. 2.5 Time-series of all India
averaged annual (left panels)
specific humidity and (right
panels) relative humidity from
(top panels) HadISDH dataset and
(bottom panels) ERA-Interim
reanalysis for the period 1979–
2015. The dashed blue lines
indicate the linear trend for the
period 1979–2015. The rate of
change during this period is
shown below the trend line. The
90% confidence intervals for
these trend estimates are assessed
in Table 2.3
Table 2.3 Observed changes in
India land mean annual and
seasonal surface specific humidity
and relative humidity between
1979 and 2015
Season
Specific humidity trends 1979–
2015 (g kg
−1 per decade)
Relative humidity trends 1979–
2015 (% per decade)
HadISDH
ERA-interim
HadISDH
ERA-interim
Annual
0.27
*
± 0.13
0.27
*
± 0.07
0.69
*
± 0.48
0.65
*
± 0.40
Winter (Dec–Feb)
0.20
*
± 0.10
0.20
*
± 0.10
0.86
*
± 0.54
0.75
*
± 0.60
Pre-monsoon (Mar–May)
0.37
*
± 0.11
0.36
*
± 0.11
0.79
*
± 0.58
0.85
*
± 0.64
Monsoon (Jun–Sep)
0.22
*
± 0.11
0.25
*
± 0.09
0.47 ± 0.60
0.45 ± 0.51
Post-monsoon (Oct–Nov)
0.33
*
± 0.25
0.37
*
± 0.16
1.00 ± 1.08
0.86
*
± 0.79
Estimates are derived from the HadISDH dataset and ERA-Interim reanalysis. Trends and significance have
been calculated as in Table 2.1. Bold values with star sign (*) indicate that trend is significant (i.e. a trend of
zero lies outside the 90% confidence interval)
2 Temperature Changes in India
27