ice concentration decreases to one tenth or less in a given harbor. It 

 is to be emphasized that breakup dates apply only to the harbor at the 

 specified stations. Quite often, the harbor will become essentially ice 

 free, but the approaches to the station may still be congested with heav- 

 ier ice concentrations. 



IV. SUMMARY 



This report shows the relationship between ice growth and air tempera- 

 ture. An average date based upon available ice information was computed 

 for disintegration of ice at various stations. The relationship between 

 the number of warming degree days and melting of specific maximum ice 

 growths is not discussed in this report. It should be stressed that other 

 parameters, such as ocean currents, winds, and tidal action, also affect 

 ice growth and dissipation at some locations. Further study of these param- 

 eters is currently being conducted. 



Table 1 

 Location Identifier for Frost Degree Day and Ice Growth Curves 



1. 



*Barter Island 



21. 



Thiile 



41. 



Isachsen 



2. 



Pt. Barrow 



22. 



Clyde River 



42. 



Mould Bay 



3. 



Wainwright 



23. 



Padloping Island 



43. 



Resolute 



4. 



Pt. Lay 



24. 



Frobisher Bay 



44. 



Dundas Harbor 



5. 



Pt. Hope 



25. 



Resolution Island 



45. 



Arctic Bay 



6. 



Kotzebue 



26. 



Hope dale 



46. 



Pond Irdet 



7. 



Wrangel Island 



27. 



Goose Bay 



47. 



Herschel Island 



8. 



Mys Schmidta 



28. 



Cartwright 



48. 



Aklavik 



9. 



ttys Vankarem 



29. 



Belle Isle 



49. 



Coppermine 



10. 



l^s Dezhneva 



30. 



lft)ernavik 



50. 



Cambridge Bay 



11. 



Uelen 



31. 



lAnanak 



51. 



Lake Harbotir 



12. 



Mys Chaplina 



32. 



Godhavn 



52. 



Nottingham Island 



13. 



Wales 



33. 



Jakobshavn 



53. 



Coral Harbor 



lU. 



Nome 



34. 



Sondre Strom 



54. 



Chesterfield 



15. 



Gambell 



35. 



Godthaab 



55. 



Churchin 



16. 



Nunivak 



36. 



Ivigtut 



56. 



Port Harrison 



17. 



Bethel 



37. 



Wanortalik 



57. 



Cape Hopes Advance 



18. 



Naknek 



38. 



Angmagssalik 



58. 



Fort Chimo 



19. 



St. Paul Island 



39. 



Nord 







20. 



Alert 



40. 



Eureka 







* Nianbers agree with those shown in figure 1. 



