OCR Text |
Show as the group parameter. In this manner the choice of value is not circumscribed ( except for p ), but the scheme can still be represented in a single illustration. Rearrangement of the individual terms in Equation ( 10), as well as in Equation ( 11) derived from ( 10), yields H+ Q + B = fr - p r gM- ( 12) XL XL . _ P . ? PCP M Q31 eL= J&+ 0^ 23iI- ( 3) With the aid of these equations the curve groups stf- = const, and M/£ EL = const, are now easily calculated and entered in the graphs. This is seen in Fig. 1 for the surface temperature iV-, where the domain of non- melting surface is expressed by the ( broken) lines parallel to the dividing line over the range of / IT" = - 30° C to / x/-- - 5° C. The dividing line between domains of non- melting and melting surfaces corresponds to / V = 0° C. Ablation represented by the quantity - M/ 0." L is depicted in Fig. 2. Here the lines concave upward correspond, from bottom to top, to - M/ C£ L = 0,00, - 0.01, and - 0.02 mm h" Vmcal cm~^ min~* deg" . They meet at the dividing line ( dashed in Fig. 2) with corresponding lines for the domain of a melting surface. The line M/ CT, = 0 of Fig. 2, along which the vapor pressure of the atmosphere e, equals that of the ice surface E(>$), is likewise depicted in Fig. 1. It divides the domain of non- melting surface into an upper part with hoarfrost deposition, in which e > E and thus - VLlOC. < 0, and a lower part with sublimation, in which e < E and thus - M/<?£, > 0. |