2.
Response
to
Comments
2.9
Individual
Responses
to
Comments
from
Organizations
The
commenters
statements
about
compressed
flow
at
the
site
indicate
a
lack
of
understanding
about
the
flow
of
air
in
the
atmospheric
boundary
layer
when
stating:
“Such
a
model
is
incapable
of
replicating
the
nature
of
compressed
flow
that
is
present
at
the
site.
As
noted
above,
the
wind
through
the
Alemany
gap
operates
as
a
compressed
flow,
and
the
movement
of
that
windfield
from
west
to
east,
and
to
the
south,
diminishes
the
intensity
of
the
wind
in
the
field.
The
physical
model
does
not
replicate
this
phenomenon,
and
thus,
has
weaknesses
in
predicting
impacts,
particularly
as
the
field
moves
south.”
At
speeds
less
than
two
hundred
miles-per-hour,
air
behaves
as
an
incompressible
fluid.
Therefore,
no
compression
of
the
air
occurs
in
the
Alemany
Gap.
When
the
colder
air
in
the
Marine
layer
spills
through
the
Alemany
Gap,
it
may
seem
as
if
it
were
compressed,
but
it
is
simply
more
dense
than
the
air
above
it
and
moves
to
displace
that
warmer
air.
However,
in
moving
downhill
from
the
Gap
into
the
wider
valley,
it
displaces
and
mixes
with
some
of
the
warmer
air,
and
slows
in
the
process.
It
is
not
necessary
to
account
for
far
upwind
conditions
in
the
atmospheric
boundary
layer,
which
is
correctly
simulated
in
these
tests
by
the
wind
tunnel,
which
is
designed
to
establish
an
initial,
carefully
structured
boundary
layer
that
then
passes
over
the
test
model
that
includes
all
upwind
topography
and
features
within
roughly
3000’
of
the
test
grid.
This
upwind
distance
is
sufficient
to
simulate
the
atmospheric
boundary
layer
that
would
reach
the
Baylands
site
and
to
simulate
the
physical
change
that
the
boundary
layer
would
undergo
while
traversing
the
Baylands
site.
As
a
result
the
boundary
layer
is
correctly
formed
when
it
passes
over
the
CPSRA
windsurfing
area.
The
changes
in
wind
conditions
due
to
Project
Site
development,
compared
to
the
existing
conditions,
are
properly
simulated
in
the
wind
tunnel.
The
SFBA
comment
letter
does
not
reveal
how
this
site
“sensitivity”
can
be
known
or
what
its
effect
would
be
on
the
atmospheric
boundary
layer.
It
is
well
known
that
certain
wind
flows
around
Bayview
Hill
can
produce
larger
scale
turbulence,
which
can
manifest
as
gustiness
at
ground-level.
As
stated
in
the
Draft
EIR,
there
will
be
changes
in
wind
speed
and
turbulence
that
would
result
from
development
of
the
Baylands
site.
However,
the
area
identified
as
the
primary
surfing
area
will
not
be
significantly
affected
by
Project
Site
development
(see
Draft
EIR
page
4.M-26).
See
through
Brisbane
Baylands
Final
EIR
2.9.10-4
May
2015