During NH summer (~June-September) the HALOE data show relative maxima in lower
stratospheric water vapor over NH midlatitudes, centered over the South Asian and
North American monsoon regions (dark shaded regions below).  These maxima are
the main cause of the large NH-SH asymmetry in water vapor (as evident this
latitude-time section).  Note the air is still extremely dry in these regions (~5 ppmv),
but relatively moist compared to the rest of the stratosphere.  The local maxima are
evidence of direct coupling with the upper troposphere, and suggest the importance
of monsoonal circulations for troposphere-stratosphere exchange.

Here's a similar diagram for ozone in the lowermost stratosphere derived from SAGE II
measurements.  Note the pronounced minimum over the South Asian monsoon region,
nearly coincident with the water vapor maximum above.  There is also a slight minimum
in ozone over North America.  Low ozone values are also a signature of coupling with
the upper troposphere.