<s>
Upper-atmospheric	B-Application
models	I-Application
are	O
simulations	O
of	O
the	O
Earth	O
's	O
atmosphere	O
between	O
20	O
and	O
100km	O
(	O
65,000	O
and	O
328,000	O
feet	O
)	O
that	O
comprises	O
the	O
stratosphere	O
,	O
mesosphere	B-General_Concept
,	O
and	O
the	O
lower	O
thermosphere	O
.	O
</s>
<s>
Whereas	O
most	O
climate	B-Application
models	I-Application
simulate	O
a	O
region	O
of	O
the	O
Earth	O
's	O
atmosphere	O
from	O
the	O
surface	O
to	O
the	O
stratopause	O
,	O
there	O
also	O
exist	O
numerical	O
models	O
which	O
simulate	O
the	O
wind	O
,	O
temperature	O
and	O
composition	O
of	O
the	O
Earth	O
's	O
tenuous	O
upper	O
atmosphere	O
,	O
from	O
the	O
mesosphere	B-General_Concept
to	O
the	O
exosphere	O
,	O
including	O
the	O
ionosphere	O
.	O
</s>
<s>
Meanwhile	O
,	O
ongoing	O
research	O
studies	O
at	O
the	O
University	O
of	O
Reading	O
show	O
that	O
unusual	O
patterns	O
in	O
the	O
polar	O
jet	O
stream	O
are	O
more	O
common	O
during	O
a	O
period	O
of	O
low	O
activity	O
in	O
the	O
solar	O
cycle	O
when	O
the	O
observed	O
sunspot	B-Application
activity	O
and	O
their	O
associated	O
solar	O
flares	O
are	O
at	O
their	O
minimum	O
.	O
</s>
