First, a bias correction algorithm, quantile delta mapping (QDM), that explicitly preserves
relative changes in precipitation quantiles is presented.
Relative changes in precipitation (in percent) for the period 2090 — 2099, relative to 1980 — 1999.
Not exact matches
Rising temperatures and
changing precipitation patterns will lead to
relative changes in agricultural production, possibly spurring rural to urban migration, or migration across borders to seek more favorable conditions.
The water vapor feedback (a generally positive feedback)-- there is an roughly exponential increase
in saturation water vapor pressure with increasing temperature, and the
relative humidity (at a given vertical level) overall tends not to
change a lot globally, though there will be different regional trends associated with shifting
precipitation patterns.
2: Our
Changing Climate, Key Message 5).2 Regional climate models (RCMs) using the same emissions scenario also project increased spring
precipitation (9 %
in 2041 - 2062
relative to 1979 - 2000) and decreased summer
precipitation (by an average of about 8 %
in 2041 - 2062
relative to 1979 - 2000) particularly
in the southern portions of the Midwest.12 Increases
in the frequency and intensity of extreme
precipitation are projected across the entire region
in both GCM and RCM simulations (Figure 18.6), and these increases are generally larger than the projected
changes in average
precipitation.12, 2
Model projections for
precipitation changes are less certain than those for temperature.12, 2 Under a higher emissions scenario (A2), global climate models (GCMs) project average winter and spring
precipitation by late this century (2071 - 2099) to increase 10 % to 20 %
relative to 1971 - 2000, while
changes in summer and fall are not expected to be larger than natural variations.
Bonfils, C.J.W., B.D. Santer, T.J. Phillips, K. Marvel, L.R. Leung, C. Doutriaux, and A. Capotondi, 2015:
Relative contributions of mean - state shifts and ENSO - driven variability to
precipitation changes in a warming climate.
Also the spatial structure of
changes in precipitation linked to altered surface temperature by convection can be improved by using higher resolution model experiments, although the
relative gain here is generally small (Di Luca et al, 2012).
With wNA forest loss, there are significant declines
in both
precipitation and temperature during the early growing season, however it is the
change in the
relative humidity that dominates the observed increase
in VPD.
The first paper cited notes (caveating that observational uncertainties are considerable) that models do not match observed
changes in subtropical
relative humidity or
in global
precipitation.
The scatter diagrams described and presented on these pages depict projected
changes in seasonal surface air temperature and
precipitation for three 30 - year periods (2010 - 2039, 2040 - 2069 and 2070 - 2099)
relative to the baseline period 1961 - 1990
in 32 sub-continental scale regions (see below).
''... report that «most trends exhibited no clear
precipitation change,» noting that «global
changes in precipitation over the Earth's land mass excluding Antarctica
relative to 1961 - 90 were estimated to be: -1.2 ± 1.7, 2.6 ± 2.5 and -5.4 ± 8.1 percent per century for the periods 1850 - 2000, 1900 - 2000 and 1950 - 2000, respectively.»
Cannon, A.J., Sobie, S.R., Murdock, T.Q., (2015) Bias correction of simulated
precipitation by quantile mapping: how well do methods preserve
relative changes in quantiles and extremes?
Use as a baseline to which
changes in the 21st century
relative to the model baseline period are applied (add for temperature, multiply for
precipitation).
PRUDENCE RCM outputs showed non-linear relationships between mean maximum temperature and indices of drought and heatwave (Good et al., 2006), while
changes in maximum 1 - day and 5 - day
precipitation amounts were systematically enhanced
relative to
changes in seasonal mean
precipitation across many regions of Europe (Beniston et al., 2007).