High-Temperature Rotational Transitions of Water in Sunspot and Laboratory Spectra

Assignments are presented for spectra of hot water obtained in absorption in sunspots (T approximately 3000&deg;C and 750 </= nu; </= 1010 cm-1) and in emission in the laboratory (T approximately 1550&deg;C and 370 </= nu; </= 930 cm-1). These assignments are made using variational nuclear motion calculations based on a high-level ab initio electronic surface, with allowance for both adiabatic and nonadiabatic corrections to the Born-Oppenheimer approximation. Some 3000 of the 4700 transitions observed in the laboratory spectrum are assigned as well as 1687 transitions observed in the sunspot spectrum. All strong lines are now assigned in the sunspot measurements. These transitions involve mostly high-lying rotational levels within the (0,0,0), (0,1,0), (0,2,0), (1,0,0), and (0,0,1) vibrational states. Transitions within the (0,3,0), (0,4,0), (1,1,0), (0,1,1), (0,2,1), (1,1,1), (1,2,0), and (1,0,1) states are also assigned. For most bands the range of Ka values observed is significantly extended, usually doubled. New features observed include numerous cases where the closely degenerate levels JKaKc and JKaKc+1 with high Ka are split by Coriolis interactions. Comparisons are made with the recent line list of Partridge and Schwenke (1997, J. Chem. Phys. 106, 4618). Copyright 1997 Academic Press. Copyright 1997Academic Press