A) is in contradiction to B) and C) "Supersaturation by the way means ABOVE 100% For the real info: tracking\pages\cirrus-test.html ...Or see the ready made ( from data of cirrus-test page ) jpg picture ------->
a) temp. and
RH for "persistant contrails"
|"Andrew Heymsfield, Larry Miloshevich, and Steven|
Aulenbach, along with Glen Sachse (NASA Langley) and
Sam Oltmans (NOAA) found that the relative humidities
with respect to water which are required to form ice
crystals in cirrus clouds decline from almost 100% near
40 degrees C to 75 or 80% from -55 to -65 degrees C.
see jpg in a)
|Heymsfield et al GRL 1998|
<saved in downloads>
|since ice crystals must have nucleated prior to|
the peak and therefore at a lower RH. HM found that
these peak RH values — their empirical aRHhn(T)"
curve — varied from water-saturation at temperatures
above -39° C to 75% RH (with respect to water) at -
55°C. HM also determined a lower bound on RHnuc in
the temperature range -35 to -47°C — about 10% below
the RHhn curve — based on the maximum RH measured
in "clear air" in a non-orographic environment
during FIRE-II. In this article we use RH and microphysical
data from balloon launches near Boulder, Colorado
and from the FIRE-II and SUCCESS experiments
to further explore bounds on RHnvc(T), particularly at
colder temperatures. Most data presented in this paper
represent mid-latitude, continental, non-convective
environments. < link and local pdf file Heymsfield >
|An expression is given for the peak RH with respect|
to water in the wave clouds (RHJ, which decreases from 100% above -39°C to 73%
at -56°C; RHhn represents the condition required for ice nucleation in the wave clouds,
and is shown to be more consistent with the homogeneous freezing of sulfuric acid
solution droplets than ammonium sulfate solution droplets.
Aircraft measurements made in cirrus during FIRE II show highly ice-supersaturated
regions in clear air, placing a lower bound on the RH required for cirrus formation
approximately equal to (RHlm-10)%. Measurements from a balloon-borne formvar ice
crystal replicator are reported which show the vertical structure of cirrus to generally
consists of three microphysically distinct regions: a highly ice-supersaturated ice production
region near cloud top, an ice-supersaturated ice crystal growth region, and a
sublimation region near cloud base formed by fallout of ice into ice-subsaturated air.
< online link and my backup file here AFRL-VS-HA-TR-1998-0051 >