If my pay drops by $10,343 a year, can my alimony be adjusted?

Yes. Changed circumstances such as a change in income would be a basis for a modification of spousal support.  You should file with the court an Order to Show Cause (court form) seeking a modification of spousal support along with a declaration under penalty of perjury stating the facts supporting the modification of spousal support.  You should also attach a proof of service to these documents you file with the court.  When you file the Order to Show Cause, the court will schedule a hearing on the modification of spousal support.  The proof of service verifies the date of mailing your documents to your former spouse.  You can use a court form proof of service or you can write your own.  If you write your own proof of service, it would just say that you are over 18 and the attached documents were sent via first class mail unless specified otherwise to ____________ (name and address of your former spouse) on ___________ (date).  You sign and date the proof of service at the bottom under penalty of perjury.  The date you sign should be the same as the date of mailing and the same date you file your documents with the court.