▁but ▁near ▁the ▁surface ▁of ▁the ▁Sun , ▁con ve ction ▁is ▁not ▁ad i ab atic . ▁ ▁Sim ulations ▁of ▁near - sur face ▁con ve ction ▁A ▁more ▁real istic ▁description ▁of ▁the ▁upp erm ost ▁part ▁of ▁the ▁con ve ction ▁zone ▁is ▁possible ▁through ▁detailed ▁three - dimensional ▁and ▁time - dependent ▁hyd rod ynam ical ▁simulations , ▁taking ▁into ▁account ▁radi ative ▁transfer ▁in ▁the ▁atmosphere . ▁Such ▁simulations ▁successfully ▁reproduce ▁the ▁observed ▁surface ▁structure ▁of ▁solar ▁gran ulation , ▁as ▁well ▁as ▁detailed ▁profiles ▁of ▁lines ▁in ▁the ▁solar ▁radi ative ▁spectrum , ▁without ▁the ▁use ▁of ▁paramet riz ed ▁models ▁of ▁tur bul ence . ▁The ▁simulations ▁only ▁cover ▁a ▁very ▁small ▁fraction ▁of ▁the ▁solar ▁radius , ▁and ▁are ▁evidently ▁far ▁too ▁time - consum ing ▁to ▁be ▁included ▁in ▁general ▁solar ▁model ing . ▁Ext rap olation ▁of ▁an ▁aver aged ▁simulation ▁through ▁the ▁ad i ab atic ▁part ▁of ▁the ▁con ve ction ▁zone ▁by ▁means ▁of ▁a ▁model ▁based ▁on ▁the ▁mixing - length ▁description , ▁demonstrated ▁that ▁the ▁ad i ab at ▁predicted ▁by ▁the ▁simulation ▁was ▁essentially ▁consistent ▁with ▁the ▁depth ▁of ▁the ▁solar ▁con ve ction ▁zone ▁as ▁determined ▁from ▁hel io se ism ology . ▁An ▁extension ▁of ▁mixing - length ▁theory , ▁including ▁effects ▁of ▁tur bul ent ▁pressure ▁and ▁kin etic ▁energy , ▁based ▁on ▁numerical ▁simulations ▁of ▁near - sur face ▁con ve ction , ▁has ▁been ▁developed . ▁ ▁This ▁section ▁is ▁adapted