How Extreme Apparitions of the Anthropogenic West African Aerosol Plume
cause Drought in the Iberian Peninsula, Floods in the U.K. and Ireland
and higher winter temperatures in Northern Europe. First Attribution and
Mechanism using data from the Terra Satellite, Last Millennium Ensemble,
and the MERRA-2 and NCEP/NCAR Reanalyses.
Abstract
The literature, Inter Governmental Panel on Climate Change (IPCC) and
the USA Climate Change Science Program suggest that aerosols can affect
the large-scale atmospheric circulation and hydrologic cycle I therefore
examine the relationship between aerosols and Iberian droughts, floods
in the UK/Ireland and higher European winter temperatures. Aerosols
exist mainly as eight continental scale plumes which typically, but not
exclusively, exist for a few months in the tropics at the end of the
local dry season when biomass burning can occur. The anthropogenic West
African aerosol Plume (WAP) exists from late December to early April and
is located in the region which drives the northern regional Hadley
Circulation towards Europe. It is therefore the prime candidate for
investigation into European, winter climate variability. Using the Last
Millennium Ensemble (1,156 years and 13,872 months of data) and the
MERRA-2 reanalysis (40 years of data) I show that drought in the Iberian
Peninsula, floods in the UK/Ireland and higher winter temperatures in
northern Europe are created by extreme apparitions of the anthropogenic
WAP. The WAP creates these effects by Aerosol Regional Dimming (ARD),
which, by altering the surface radiation budget under the plume and
warming the upper atmosphere, forces the regional Hadley Circulation
into an abnormal seasonal position. These effects alter the regional
atmospheric circulation systems and hydrologic cycle in Europe thereby
causing drought, floods and higher temperatures and, as the WAP has
intensified over recent decades, created climate change.