witness a prevention of enhanced ice sheet mass loss this year (2017)
because of extra snowfall. With more moisture in Earth’s
atmosphere and a pattern in ice cores and elsewhere, the extra snow
is consistent with climate warming.
in the graphic below:1.) well above normal snow accumulation on
Greenland starting October 2016 and 2.) a 27 June – 5
July ‘mid summer’ snowfall.
this critical point of the year, mid melt season, the surface
mass input (SMB) is 1.2x above normal. By comparison, in the
record loss year 2012, the mass input (the Surface Mass Balance, or
SMB) was roughly 1.2x below normal.
extra snow cover and associated high to average albedo is maintaining
the ice sheet. This is good news. And climate change contrarians, do
read to the bottom of this article!
graphic below how the albedo over the ice sheet declines through the
year, as normal, then the 27 June to 5 July jump in the blue curve
‘reflects’ (pun intended) mid summer snowfall.
graphic below shows the Greenland whiteness (albedo) map is overall
very blue around the periphery where most melting occurs…
punctuation of melt this year is not necessarily enough to offset the
other source of ice mass loss: iceberg calving. Yet, as compared to
the ‘melt pause’ year 2013 (see GRACE satellite data below), I
would not be surprised to see the ice sheet have a no mass loss year
since 1900 indicate overall precipitation increase (IPCC
AR5 Chapter 2, Hartmann et al. 2013). Further, future climate
projections suggest a continued widespread increase in
Arctic precipitation, especially over the Arctic Ocean (IPCC AR5
Chapter 12, Collins et al. 2013). See how blue the Arctic is in
the graphic below…
show more snow with climate warming
found and published a robust Northern Hemisphere air temperature
correlation with Greenland accumulation from ice cores (Box et al.
2013). The relationship has a slope of 7% per degree C
of Northern Hemisphere Air temperature increase, lying on
vapor pressure curve,
reinforcing that we can expect more snow in a warming climate
(Kapsner et al. 1995) and in agreement with the IPCC AR5 Chapter 12
Meteorological Institute: Jesper Rosberg explains, “we have
seen a persistent positive North Atlantic Oscillation this summer and
the jet stream has been very far south of Greenland with very cold
air over the ice sheet, so the precipitation falling this summer has
mostly been snow, rather [than] rain.”
with global atmospheric absolute humidity rising due to warming, now
all weather systems form in an environment that is wetter and warmer
on average. So, as I see it, it’s simple to expect the average
weather system to dump more precipitation, whether that is rain or
I’ve presented that in a warmer atmosphere, higher absolute
humidity, increased potential (and actual) precipitation rates… We
see a global pattern of precipitation increase. Now, what may seem
ironic is that soil moisture can decrease in a warming climate
despite increased precipitation. How? evaporation rates increase more
than soil recharge rates. On glaciers in the Arctic, we still get
more net ice loss. Why? The increase in melting is larger than the
increase in snowfall. So, warmer Arctic, more snow, is an example of
a negative feedback.
J.E., N. Cressie, D.H. Bromwich, J. Jung, M. van den Broeke, J.H.
van Angelen, R.R. Forster, C. Miège, E. Mosley-Thompson, B.
Vinther, J.R. McConnell. 2013. Greenland
ice sheet mass balance reconstruction. Part I: net snow accumulation
Journal of Climate, 26, 3919–3934. doi:10.1175/JCLI-D-12-00373.1
M., R. Knutti, J. Arblaster, J.-L. Dufresne, T. Fichefet, P.
Friedlingstein, X. Gao, W.J. Gutowski, T. Johns, G. Krinner, M.
Shongwe, C. Tebaldi, A.J. Weaver and M. Wehner, 2013: Long-term
Climate Change: Projections, Commitments and
Change 2013: The Physical Science Basis.Contribution
of Working Group I to the Fifth Assessment Report of the
Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin,
G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y.
Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press,
Cambridge, United Kingdom and New York, NY, USA.
D.L., A.M.G. Klein Tank, M. Rusticucci, L.V. Alexander, S.
Brönnimann, Y. Charabi, F.J. Dentener, E.J. Dlugokencky, D.R.
Easterling, A. Kaplan, B.J. Soden, P.W. Thorne, M. Wild and P.M.
Zhai, 2013. Observations:
atmosphere and surface. In:
Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J.
Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.), Climate
Change 2013: The Physical Science Basis.
Contribution of Working Group I to the Fifth Assessment Report of
the Intergovernmental Panel on Climate Change. Cambridge University
W.R., R.B. Alley, C.A. Shuman, S. Anandakrishnan and P.M. Grootes.
influence of atmospheric circulation on snow accumulation in
Greenland over the past 18,000 years. Nature,