xxxx
 Natural cirrus formation
        145%RHi
-36C:   101.65%RH  
-37C:   100.63%RH  
-38C:    99.62%RH  
-39C:    98.75%RH  
-40C:    97.73%RH
-41C:    96.72%RH
-42C:    95.85%RH
-43C:    94.98%RH
-44C:    93.96%RH
-45C:    92.95%RH
-46C:    92.08%RH
-47C:    91.21%RH
-48C:   90.34%RH
-49C:   89.32%RH
-50C:   88.45%RH
-51C:   87.58%RH
-52C:   86.86%RH
-53C:   85.99%RH
-54C:   85.12%RH
-55C:   84.25%RH
-56C:   83.38%RH
-57C:   82.65%RH
-58C:   81.78%RH
-59C:   81.06%RH
-60C:   78.74%RH
-61C:  79.46%RH
-62C:  78.74%RH
-63C:  77.87%RH
-64C:  77.14%RH
-65C:  76.42%RH
-66C:  75.69%RH
-67C:  74.97%RH
-68C:  74.24%RH
-69C:  73.52%RH
-70C:  72.79%RH
-71C:  72.07%RH
-72C:  71.49%RH
-73C:  70.76%RH
-74C:  70.04%RH
-75C:  69.46%RH
-76C:  68.73%RH
-77C:  68.15%RH
-78C:  67.43%RH
-79C:  66.85%RH
-80C:  66.27%RH
-81C:  65.54%RH
-82C:  64.96%RH
-83C:  64.38%RH
-84C:  63.80%RH
-85C:  63.22%RH
-86C:  62.64%RH
Contrail-cirrus requirements
        according to Simon Unterstrasser
     RHi 120%
-36C   84.12%RH
-37C   83.28%RH
-38C   82.44%RH
-39C   81.72%RH
-40C   80.88%RH
-41C   80.04%RH
-42C   79.32%RH
-43C   78.60%RH
-44C   77.76%RH
-45C   76.92%RH
-46C   76.20%RH
-47C   75.48%RH
-48C   74.76%RH
-49C   73.92%RH
-50C   73.20%RH
-51C   72.48%RH
-52C   71.88%RH
-53C   71.16%RH
-54C   70.44%RH
-55C   69.72%RH
-56C   69.00%RH
-57C   68.40%RH
-58C   67.68%RH
-59C   67.08%RH
-60C   65.16%RH
-61C   65.76%RH
-62C   65.16%RH
-63C   64.44%RH
-64C   63.84%RH
-65C   63.24%RH
-66C   62.64%RH
-67C   62.04%RH
-68C   61.44%RH
-69C   60.84%RH
-70C   60.24%RH
-71C   59.64%RH
-72C   59.16%RH
-73C   58.56%RH
-74C   57.96%RH
-75C   57.48%RH
-76C   56.88%RH
-77C   56.40%RH
-78C   55.80%RH
-79C   55.32%RH
-80C   54.84%RH
-81C   54.24%RH
-82C   53.76%RH
-83C   53.28%RH
-84C   52.80%RH
-85C   52.32%RH
-86C   51.84%RH
-87C   51.36%RH
    Frost-Point
-35C: 70.9%RH
-36C: 70.2%RH
-37C: 69.5%RH
-38C: 68.8%RH
-39C: 68.2%RH
-40C: 67.5%RH
-41C: 66.8%RH
-42C: 66.2%RH
-43C: 65.6%RH
-44C: 64.9%RH
-45C: 64.2%RH
-46C: 63.6%RH
-47C: 63.0%RH
-48C: 62.4%RH
-49C: 61.7%RH
-50C: 61.1%RH
-51C: 60.5%RH
-52C: 60.0%RH
-53C: 59.4%RH
-54C: 58.8%RH
-55C: 58.2%RH
-56C: 57.6%RH
-57C: 57.1%RH
-58C: 56.5%RH
-59C: 56.0%RH
-60C: 54.4%RH
-61C: 54.9%RH
-62C: 54.4%RH
-63C: 53.8%RH
-64C: 53.3%RH
-65C: 52.8%RH
-66C: 52.3%RH
-67C: 51.8%RH
-68C: 51.3%RH
-69C: 50.8%RH
-70C: 50.3%RH
-71C: 49.8%RH
-72C: 49.4%RH
-73C: 48.9%RH
-74C: 48.4%RH
-75C: 48.0%RH
-76C: 47.5%RH
-77C: 47.1%RH
-78C: 46.6%RH
-79C: 46.2%RH
-80C: 45.8%RH
-81C: 45.3%RH
-82C: 44.9%RH
-83C: 44.5%RH
-84C: 44.1%RH
-85C: 43.7%RH
-86C: 43.3%RH
-87C: 42.9%RH
             
             Persistent-Contrail                                     Contrail-Cirrus                                                  Natural-Cirrus
    Frost-Point
-35C: 70.9%RH
-36C: 70.2%RH
-37C: 69.5%RH
-38C: 68.8%RH
-39C: 68.2%RH
-40C: 67.5%RH
-41C: 66.8%RH
-42C: 66.2%RH
-43C: 65.6%RH
-44C: 64.9%RH
-45C: 64.2%RH
-46C: 63.6%RH
-47C: 63.0%RH
-48C: 62.4%RH
-49C: 61.7%RH
-50C: 61.1%RH
-51C: 60.5%RH
-52C: 60.0%RH
-53C: 59.4%RH
-54C: 58.8%RH
-55C: 58.2%RH
-56C: 57.6%RH
-57C: 57.1%RH
-58C: 56.5%RH
-59C: 56.0%RH
-60C: 54.4%RH
-61C: 54.9%RH
-62C: 54.4%RH
-63C: 53.8%RH
-64C: 53.3%RH
-65C: 52.8%RH
-66C: 52.3%RH
-67C: 51.8%RH
-68C: 51.3%RH
-69C: 50.8%RH
-70C: 50.3%RH
-71C: 49.8%RH
-72C: 49.4%RH
-73C: 48.9%RH
-74C: 48.4%RH
-75C: 48.0%RH
-76C: 47.5%RH
-77C: 47.1%RH
-78C: 46.6%RH
-79C: 46.2%RH
-80C: 45.8%RH
-81C: 45.3%RH
-82C: 44.9%RH
-83C: 44.5%RH
-84C: 44.1%RH
-85C: 43.7%RH
-86C: 43.3%RH
-87C: 42.9%RH
     RHi 120%
-36C   84.12%RH
-37C   83.28%RH
-38C   82.44%RH
-39C   81.72%RH
-40C   80.88%RH
-41C   80.04%RH
-42C   79.32%RH
-43C   78.60%RH
-44C   77.76%RH
-45C   76.92%RH
-46C   76.20%RH
-47C   75.48%RH
-48C   74.76%RH
-49C   73.92%RH
-50C   73.20%RH
-51C   72.48%RH
-52C   71.88%RH
-53C   71.16%RH
-54C   70.44%RH
-55C   69.72%RH
-56C   69.00%RH
-57C   68.40%RH
-58C   67.68%RH
-59C   67.08%RH
-60C   65.16%RH
-61C   65.76%RH
-62C   65.16%RH
-63C   64.44%RH
-64C   63.84%RH
-65C   63.24%RH
-66C   62.64%RH
-67C   62.04%RH
-68C   61.44%RH
-69C   60.84%RH
-70C   60.24%RH
-71C   59.64%RH
-72C   59.16%RH
-73C   58.56%RH
-74C   57.96%RH
-75C   57.48%RH
-76C   56.88%RH
-77C   56.40%RH
-78C   55.80%RH
-79C   55.32%RH
-80C   54.84%RH
-81C   54.24%RH
-82C   53.76%RH
-83C   53.28%RH
-84C   52.80%RH
-85C   52.32%RH
-86C   51.84%RH
-87C   51.36%RH
        145%RHi
-36C: 101.65%RH  
-37C: 100.63%RH  
-38C:   99.62%RH  
-39C:   98.75%RH  
-40C:   97.73%RH
-41C:   96.72%RH
-42C:   95.85%RH
-43C:   94.98%RH
-44C:   93.96%RH
-45C:   92.95%RH
-46C:   92.08%RH
-47C:   91.21%RH
-48C:   90.34%RH
-49C:   89.32%RH
-50C:   88.45%RH
-51C:   87.58%RH
-52C:   86.86%RH
-53C:   85.99%RH
-54C:   85.12%RH
-55C:   84.25%RH
-56C:   83.38%RH
-57C:   82.65%RH
-58C:   81.78%RH
-59C:   81.06%RH
-60C:   78.74%RH
-61C:  79.46%RH
-62C:  78.74%RH
-63C:  77.87%RH
-64C:  77.14%RH
-65C:  76.42%RH
-66C:  75.69%RH
-67C:  74.97%RH
-68C:  74.24%RH
-69C:  73.52%RH
-70C:  72.79%RH
-71C:  72.07%RH
-72C:  71.49%RH
-73C:  70.76%RH
-74C:  70.04%RH
-75C:  69.46%RH
-76C:  68.73%RH
-77C:  68.15%RH
-78C:  67.43%RH
-79C:  66.85%RH
-80C:  66.27%RH
-81C:  65.54%RH
-82C:  64.96%RH
-83C:  64.38%RH
-84C:  63.80%RH
-85C:  63.22%RH
-86C:  62.64%RH

for jpg here ...
or..


              Persistent-Contrail                                     Contrail-Cirrus                                              Natural-Cirrus
    Frost-Point
-35C: 70.9%RH
-36C: 70.2%RH
-37C: 69.5%RH
-38C: 68.8%RH
-39C: 68.2%RH
-40C: 67.5%RH
-41C: 66.8%RH
-42C: 66.2%RH
-43C: 65.6%RH
-44C: 64.9%RH
-45C: 64.2%RH
-46C: 63.6%RH
-47C: 63.0%RH
-48C: 62.4%RH
-49C: 61.7%RH
-50C: 61.1%RH
-51C: 60.5%RH
-52C: 60.0%RH
-53C: 59.4%RH
-54C: 58.8%RH
-55C: 58.2%RH
-56C: 57.6%RH
-57C: 57.1%RH
-58C: 56.5%RH
-59C: 56.0%RH
-60C: 54.4%RH
-61C: 54.9%RH
-62C: 54.4%RH
-63C: 53.8%RH
-64C: 53.3%RH
-65C: 52.8%RH
-66C: 52.3%RH
-67C: 51.8%RH
-68C: 51.3%RH
-69C: 50.8%RH
-70C: 50.3%RH
-71C: 49.8%RH
-72C: 49.4%RH
-73C: 48.9%RH
-74C: 48.4%RH
-75C: 48.0%RH
-76C: 47.5%RH
-77C: 47.1%RH
-78C: 46.6%RH
-79C: 46.2%RH
-80C: 45.8%RH
-81C: 45.3%RH
-82C: 44.9%RH
-83C: 44.5%RH
-84C: 44.1%RH
-85C: 43.7%RH
-86C: 43.3%RH
-87C: 42.9%RH
     RHi 120%
-36C   84.12%RH
-37C   83.28%RH
-38C   82.44%RH
-39C   81.72%RH
-40C   80.88%RH
-41C   80.04%RH
-42C   79.32%RH
-43C   78.60%RH
-44C   77.76%RH
-45C   76.92%RH
-46C   76.20%RH
-47C   75.48%RH
-48C   74.76%RH
-49C   73.92%RH
-50C   73.20%RH
-51C   72.48%RH
-52C   71.88%RH
-53C   71.16%RH
-54C   70.44%RH
-55C   69.72%RH
-56C   69.00%RH
-57C   68.40%RH
-58C   67.68%RH
-59C   67.08%RH
-60C   65.16%RH
-61C   65.76%RH
-62C   65.16%RH
-63C   64.44%RH
-64C   63.84%RH
-65C   63.24%RH
-66C   62.64%RH
-67C   62.04%RH
-68C   61.44%RH
-69C   60.84%RH
-70C   60.24%RH
-71C   59.64%RH
-72C   59.16%RH
-73C   58.56%RH
-74C   57.96%RH
-75C   57.48%RH
-76C   56.88%RH
-77C   56.40%RH
-78C   55.80%RH
-79C   55.32%RH
-80C   54.84%RH
-81C   54.24%RH
-82C   53.76%RH
-83C   53.28%RH
-84C   52.80%RH
-85C   52.32%RH
-86C   51.84%RH
-87C   51.36%RH
        145%RHi
-36C 101.65%RH  
-37C 100.63%RH  
-38C:  99.62%RH  
-39C:  98.75%RH  
-40C:  97.73%RH
-41C:  96.72%RH
-42C:  95.85%RH
-43C:  94.98%RH
-44C:  93.96%RH
-45C:  92.95%RH
-46C:  92.08%RH
-47C:  91.21%RH
-48C:  90.34%RH
-49C:  89.32%RH
-50C:  88.45%RH
-51C:  87.58%RH
-52C:  86.86%RH
-53C:  85.99%RH
-54C:  85.12%RH
-55C:  84.25%RH
-56C:  83.38%RH
-57C:  82.65%RH
-58C:  81.78%RH
-59C:  81.06%RH
-60C:  78.74%RH
-61C:  79.46%RH
-62C:  78.74%RH
-63C:  77.87%RH
-64C:  77.14%RH
-65C:  76.42%RH
-66C:  75.69%RH
-67C:  74.97%RH
-68C:  74.24%RH
-69C:  73.52%RH
-70C:  72.79%RH
-71C:  72.07%RH
-72C:  71.49%RH
-73C:  70.76%RH
-74C:  70.04%RH
-75C:  69.46%RH
-76C:  68.73%RH
-77C:  68.15%RH
-78C:  67.43%RH
-79C:  66.85%RH
-80C:  66.27%RH
-81C:  65.54%RH
-82C:  64.96%RH
-83C:  64.38%RH
-84C:  63.80%RH
-85C:  63.22%RH
-86C:  62.64%RH

Sustained but not forming contrail-cirrus
110%RHI
-39C 75.02%RH
-40C 74.25%RH
-41C 73.48%RH
-42C 72.82%RH
-43C 72.16%RH
-44C 71.39%RH
-45C 70.62%RH
-46C 69.96%RH
-47C 69.30%RH
-48C 68.64%RH
-49C 67.87%RH
-50C 67.21%RH
-51C 66.55%RH
-52C 66.00%RH
-53C 65.34%RH
-54C 64.68%RH
-55C 64.02%RH
-56C 63.36%RH
-57C 62.81%RH
-58C 62.15%RH
-59C 61.60%RH
-60C 59.84%RH

-61C 60.39%RH
-62C 59.84%RH
-63C 59.18%RH
-64C 58.63%RH
-65C 58.08%RH
-66C 57.53%RH
-67C 56.98%RH
-68C 56.43%RH
-69C 55.88%RH
-70C 55.33%RH
-71C 54.78%RH
-72C 54.34%RH
-73C 53.79%RH
-74C 53.24%RH
-75C 52.69
%RH
-76C 52.14%RH
-77C 51.7%RH
-78C 51.26%RH
-79C 50.82%RH
-80C 50.38%RH
-81C 49.72%RH
-82C 49.28%RH
-83C 48.84%RH

Sustained but not forming contrail-cirrus   RH needed for contrail-cirrus forming
110%RHI
-39C 75.02%RH
-40C 74.25%RH
-41C 73.48%RH
-42C 72.82%RH
-43C 72.16%RH
-44C 71.39%RH
-45C 70.62%RH
-46C 69.96%RH
-47C 69.30%RH
-48C 68.64%RH
-49C 67.87%RH
-50C 67.21%RH
-51C 66.55%RH
-52C 66.00%RH
-53C 65.34%RH
-54C 64.68%RH
-55C 64.02%RH
-56C 63.36%RH
-57C 62.81%RH
-58C 62.15%RH
-59C 61.60%RH
-60C 59.84%RH

-61C 60.39%RH
-62C 59.84%RH
-63C 59.18%RH
-64C 58.63%RH
-65C 58.08%RH
-66C 57.53%RH
-67C 56.98%RH
-68C 56.43%RH
-69C 55.88%RH
-70C 55.33%RH
-71C 54.78%RH
-72C 54.34%RH
-73C 53.79%RH
-74C 53.24%RH
-75C 52.69
%RH
-76C 52.14%RH
-77C 51.7%RH
-78C 51.26%RH
-79C 50.82%RH
-80C 50.38%RH
-81C 49.72%RH
-82C 49.28%RH
-83C 48.84%RH
     RHi 120%
-36C   84.12%RH
-37C   83.28%RH
-38C   82.44%RH
-39C   81.72%RH
-40C   80.88%RH
-41C   80.04%RH
-42C   79.32%RH
-43C   78.60%RH
-44C   77.76%RH
-45C   76.92%RH
-46C   76.20%RH
-47C   75.48%RH
-48C   74.76%RH
-49C   73.92%RH
-50C   73.20%RH
-51C   72.48%RH
-52C   71.88%RH
-53C   71.16%RH
-54C   70.44%RH
-55C   69.72%RH
-56C   69.00%RH
-57C   68.40%RH
-58C   67.68%RH
-59C   67.08%RH
-60C   65.16%RH
-61C   65.76%RH
-62C   65.16%RH
-63C   64.44%RH
-64C   63.84%RH
-65C   63.24%RH
-66C   62.64%RH
-67C   62.04%RH
-68C   61.44%RH
-69C   60.84%RH
-70C   60.24%RH
-71C   59.64%RH
-72C   59.16%RH
-73C   58.56%RH
-74C   57.96%RH
-75C   57.48%RH
-76C   56.88%RH
-77C   56.40%RH
-78C   55.80%RH
-79C   55.32%RH
-80C   54.84%RH
-81C   54.24%RH
-82C   53.76%RH
-83C   53.28%RH
-84C   52.80%RH
-85C   52.32%RH
-86C   51.84%RH
-87C   51.36%RH

All four Tables just for the fun of it


               Persistent-contrail                                                                                       RH needed for contrail-cirrus forming
    Frost-Point
-35C: 70.9%RH
-36C: 70.2%RH
-37C: 69.5%RH
-38C: 68.8%RH
-39C: 68.2%RH
-40C: 67.5%RH
-41C: 66.8%RH
-42C: 66.2%RH
-43C: 65.6%RH
-44C: 64.9%RH
-45C: 64.2%RH
-46C: 63.6%RH
-47C: 63.0%RH
-48C: 62.4%RH
-49C: 61.7%RH
-50C: 61.1%RH
-51C: 60.5%RH
-52C: 60.0%RH
-53C: 59.4%RH
-54C: 58.8%RH
-55C: 58.2%RH
-56C: 57.6%RH
-57C: 57.1%RH
-58C: 56.5%RH
-59C: 56.0%RH
-60C: 54.4%RH
-61C: 54.9%RH
-62C: 54.4%RH
-63C: 53.8%RH
-64C: 53.3%RH
-65C: 52.8%RH
-66C: 52.3%RH
-67C: 51.8%RH
-68C: 51.3%RH
-69C: 50.8%RH
-70C: 50.3%RH
-71C: 49.8%RH
-72C: 49.4%RH
-73C: 48.9%RH
-74C: 48.4%RH
-75C: 48.0%RH
-76C: 47.5%RH
-77C: 47.1%RH
-78C: 46.6%RH
-79C: 46.2%RH
-80C: 45.8%RH
-81C: 45.3%RH
-82C: 44.9%RH
-83C: 44.5%RH
-84C: 44.1%RH
-85C: 43.7%RH
-86C: 43.3%RH
-87C: 42.9%RH
Sustained but not forming contrail-cirrus
110%RHI
-39C 75.02%RH
-40C 74.25%RH
-41C 73.48%RH
-42C 72.82%RH
-43C 72.16%RH
-44C 71.39%RH
-45C 70.62%RH
-46C 69.96%RH
-47C 69.30%RH
-48C 68.64%RH
-49C 67.87%RH
-50C 67.21%RH
-51C 66.55%RH
-52C 66.00%RH
-53C 65.34%RH
-54C 64.68%RH
-55C 64.02%RH
-56C 63.36%RH
-57C 62.81%RH
-58C 62.15%RH
-59C 61.60%RH
-60C 59.84%RH

-61C 60.39%RH
-62C 59.84%RH
-63C 59.18%RH
-64C 58.63%RH
-65C 58.08%RH
-66C 57.53%RH
-67C 56.98%RH
-68C 56.43%RH
-69C 55.88%RH
-70C 55.33%RH
-71C 54.78%RH
-72C 54.34%RH
-73C 53.79%RH
-74C 53.24%RH
-75C 52.69
%RH
-76C 52.14%RH
-77C 51.7%RH
-78C 51.26%RH
-79C 50.82%RH
-80C 50.38%RH
-81C 49.72%RH
-82C 49.28%RH
-83C 48.84%RH

     RHi 120%
-36C   84.12%RH
-37C   83.28%RH
-38C   82.44%RH
-39C   81.72%RH
-40C   80.88%RH
-41C   80.04%RH
-42C   79.32%RH
-43C   78.60%RH
-44C   77.76%RH
-45C   76.92%RH
-46C   76.20%RH
-47C   75.48%RH
-48C   74.76%RH
-49C   73.92%RH
-50C   73.20%RH
-51C   72.48%RH
-52C   71.88%RH
-53C   71.16%RH
-54C   70.44%RH
-55C   69.72%RH
-56C   69.00%RH
-57C   68.40%RH
-58C   67.68%RH
-59C   67.08%RH
-60C   65.16%RH
-61C   65.76%RH
-62C   65.16%RH
-63C   64.44%RH
-64C   63.84%RH
-65C   63.24%RH
-66C   62.64%RH
-67C   62.04%RH
-68C   61.44%RH
-69C   60.84%RH
-70C   60.24%RH
-71C   59.64%RH
-72C   59.16%RH
-73C   58.56%RH
-74C   57.96%RH
-75C   57.48%RH
-76C   56.88%RH
-77C   56.40%RH
-78C   55.80%RH
-79C   55.32%RH
-80C   54.84%RH
-81C   54.24%RH
-82C   53.76%RH
-83C   53.28%RH
-84C   52.80%RH
-85C   52.32%RH
-86C   51.84%RH
-87C   51.36%RH
                    Natural-Cirrus
        145%RHi
-36C 101.65%RH  
-37C 100.63%RH  
-38C:  99.62%RH  
-39C:  98.75%RH  
-40C:  97.73%RH
-41C:  96.72%RH
-42C:  95.85%RH
-43C:  94.98%RH
-44C:  93.96%RH
-45C:  92.95%RH
-46C:  92.08%RH
-47C:  91.21%RH
-48C:  90.34%RH
-49C:  89.32%RH
-50C:  88.45%RH
-51C:  87.58%RH
-52C:  86.86%RH
-53C:  85.99%RH
-54C:  85.12%RH
-55C:  84.25%RH
-56C:  83.38%RH
-57C:  82.65%RH
-58C:  81.78%RH
-59C:  81.06%RH
-60C:  78.74%RH
-61C:  79.46%RH
-62C:  78.74%RH
-63C:  77.87%RH
-64C:  77.14%RH
-65C:  76.42%RH
-66C:  75.69%RH
-67C:  74.97%RH
-68C:  74.24%RH
-69C:  73.52%RH
-70C:  72.79%RH
-71C:  72.07%RH
-72C:  71.49%RH
-73C:  70.76%RH
-74C:  70.04%RH
-75C:  69.46%RH
-76C:  68.73%RH
-77C:  68.15%RH
-78C:  67.43%RH
-79C:  66.85%RH
-80C:  66.27%RH
-81C:  65.54%RH
-82C:  64.96%RH
-83C:  64.38%RH
-84C:  63.80%RH
-85C:  63.22%RH
-86C:  62.64%RH


How were those tables made? By using the Vaisala frost point calculator version 2.1    http://vaisala-humidity-calculator.software.informer.com/2.1/
The saturation point with regards to ice is 0.1 degrees under the frost point.
Supersaturation was calculated by first using the frost point minus 0.1 and multiplicated by the supersaturation factor.
If supersaturation was 120% then the calculation went: Frost point minus 0.1 multiplied by 1.2
How did I get the figures for: Persistent but not spreading contrails? Yellow table?
chem/misc/The Yellow Table.html
In ice supersaturated air
contrails are persistent
weakly ice supersaturated -
only ice in secondary wake
is persistent
strongly ice supersaturated
- ice in primary and
secondary wake persistent
Contrail cirrus evolve in supersaturated area
http://aero-net.info/fileadmin/aeronet_files/links/documents/DLR/Schumann_Contrails.pdf
<backup here: Schumann_Contrails>
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Sustained spreading persistent contrails ( but not forming ) violet table? Actually the consensus is 110-130%. The grey table on the following link is outdated.
chem/misc/Heterogeneous or Homogeneous.html  Ignore the figures with regards to homogeneous ice nucleation. They are 145% RHi or higher.
fusina_etal07
For heterogeneous nucleation, the
freezing thresholds are smaller, probably in the range 110–
140%RHi [e.g., Mo¨hler et al., 2006; DeMott et al., 2003].
[3] The properties and global distributions of ice supersaturated
regions (ISSRs) were discovered during the last
years [e.g., Gierens et al., 1999, 2000; Spichtinger et al.,
2003a, 2003b; Gettelman et al., 2006].

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Forming of spreading persistent contrails ( also known as contrail-cirrus or heterogeneous formed cirrus ). Corral table. According to Simon Unterstrasser and others.
chem/misc/Natural%20Cirrus%20Unterstrasser.html   in German. A jpg capture is here  ...

http://edoc.ub.uni-muenchen.de/9464/1/Unterstrasser_Simon.pdf
Numerische Simulationen von Kondensstreifen und
deren ¨Ubergang in Zirren
Dissertation
der Fakult¨at fuer Physik der
Ludwig-Maximilians-Universit¨at Muenchen
vorgelegt von Dipl.-Tech. Math. Simon Unterstraßer
aus Kraiburg am Inn
Muenchen, Oktober 2008
chem/tracking/pages/Simon Unterstrasser.html
http://edoc.ub.uni-muenchen.de/9464/1/Unterstrasser_Simon.pdf
Numerische Simulationen von Kondensstreifen und
deren ¨Ubergang in Zirren
Dissertation
der Fakult¨at f¨ur Physik der
Ludwig-Maximilians-Universit¨at M¨unchen
vorgelegt von Dipl.-Tech. Math. Simon Unterstraßer
aus Kraiburg am Inn
M¨unchen, Oktober 2008
Wichtige Ergebnisse der Simulationen sind, daß
hohe ¨Ubers¨attigungen von si ≥ 25% notwendig sind, damit sich der Kondensstreifen
ausbreiten kann (Jensen et al., 1998). Best¨atigt wird dies durch die Fallstudie in Gierens
und Jensen (1998), welche verdeutlicht, daß sich ein Kondensstreifen aufgrund
der geringen ¨Ubers¨attigung innerhalb einer halben Stunde aufl¨ost.
Kondensstreifen und flugzeuginduzierte Zirren sind oft gut beobachtbar, da sie in
ansonsten wolkenfreien Regionen existieren k¨onnen. Man kann daraus folgern, daß
Kondensstreifen in Regionen fortbestehen und sich ausbreiten k¨onnen, in denen die
Atmosph¨are die Voraussetzungen f¨ur die Bildung von nat¨urlichen Zirren nicht erf¨ullt.
Die Eisteilchen in nat¨urlich gebildeten Zirren entstehen meist durch homogene Nukleation.
Dazu muß die relative Feuchte in der Umgebung ¨uber einem Schwellwert
RHhom von > 145% liegen (Koop et al., 2000). Dieser Schwellwert ist als gepunktete
Linie in Abbildung 1.1 in Abh¨angigkeit von der Temperatur angegeben. Soweit nicht
anders erw¨ahnt, ist in dieser Arbeit immer die relative Feuchte RHi bez¨uglich der
Eisphase gemeint. Die ¨Ubers¨attigung si ist definiert als si = RHi − 1. Tritt heterogene
Nukleation (Vali, 1985; DeMott et al., 2003) auf, k¨onnen Eisteilchen auch bei
geringeren ¨Ubers¨attigungen entstehen (DeMott, 1990; DeMott et al., 1999; Gierens,
2003).
http://www.youtube.com/watch?v=6ygk98kEQfk
Cosmic rays and climate.
Comment: So according to Dipl.-Tech. Math. Simon Unterstraßer  if the RHi is under 125% the persistent contrail will fade away within the next 30 minutes and can not spread.
Die Eisteilchen in nat¨urlich gebildeten Zirren entstehen meist durch homogene Nukleation.
Translation:
Naturally grown cirrus is mostly created via homogeneous ice nucleation.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Natural formed via ice crystal nucleation aka homogeneous formed cirrus. The grey table.
chem/misc/The Grey Table.html
However, the formation of cirrus
requires higher relative humidity than for contrail persistence: Ice particles form from the abundant
small droplets by homogeneous freezing only at high relative humidity with respect to ice-saturation,
at RHi of the order 145 to 165 % or higher [39]. Also the formation of ice particles by heterogeneous
nucleation often requires RHi of 110 % or more [27] (with few exceptions such as desert dust particles).
Often, RHi is large enough to let contrails persist and develop into cirrus but not large enough to
let cirrus clouds form naturally. Since contrail persistence requires at least ice saturation, a sky full of
contrails but without natural cirrus shows that cases occur with humidity above ice-saturation but below
the threshold for cirrus formation.
Schumann_Contrails.pdf
xxxx
tracking\mahapatra09_report_nearlyfinal.pdf
II. HOMOGENEOUS ICE NUCLEATION
The formation of cirrus clouds in environments with moderate
to strong upward draughts or few germs is dominated
by homogeneous nucleation, as elaborated by Tompkins et al.
[5]. The relative humidity with respect to ice increases up to a
critical threshold RHcrit of supersaturation as high as 150%,
before nucleation begins under conditions of low temperature
and large difference between the vapour pressures of liquid
water and ice saturation.
P. Mahapatra, M. Milz and S. Buehler
Satellite Atmospheric Science Group, Department of Space Science, Luleå University of Technology, Kiruna, Sweden
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
http://www.lmd.ens.fr/wavacs/Lectures/Schiller-3.pdf
<backup here: Schiller-3>
Homogeneous / heterogeneous ice nucleation
homogeneous ice nucleation 140-170%  RHi (ice)
heterogeneous ice nucleation 100-150% RHi (ice)
Comment: Depending on temperature. The colder at is the lower the supersaturation with regards to ice can be.
Starting by -40C and colder.
xxxx

For jpg showing all 4  tables here...

Back to Index with more info there.