isotherm• An isotherm is a pressure-volume plot at constant temperature.• The boundary between the edge of the southernzone and the tundra is the 2°CJulyisotherm.• Aleksandrova rather confusingly calls the northern and southern beltsarctic tundra and subarctic tundra, separating them by the 6°C July isotherm.• Starting at Cape Sata in the farsouth, cherrytreesburst into flower and a pinkisotherm of blossomssweeps northwards.• The critical temperature of C02 is 304 K. The isotherm at this temperature is called the critical isotherm.• The isotherm for CO2 at 321 K shows that the gas does not liquefy whatever the pressure or volume at this temperature.• The winterisotherm for this might well be above the next critical temperature for water, i.e. 30°C.
Originisotherm
(1800-1900)Frenchisotherme, from Greekiso- ( → ISO-) + therme“heat”