who is current presiding officer of the senate
Presiding Officer of the United States Senate The Presiding Officer of the United States Senate is the person who presides over the United States Senate and is charged with maintaining order and decorum, recognizing members to speak, and interpreting the Senate's rules, practices, and precedents. Senate presiding officer is a role, not an actual office. The actual role is usually performed by one of three officials: the Vice President; an elected United States Senator; or, in special cases, the Chief Justice. Outside the constitutionally mandated roles, the actual appointment of a person to do the job of presiding over the Senate as a body is governed by Rule I of the Standing Rules.
Presiding Officer of the United States Senate The U.S. Constitution also provides for appointment of one of the elected Senators to serve as President pro tempore. This Senator presides when the vice president was absent from the body. The President pro tempore is selected by the body specifically for the role of presiding in the absence of (as the meaning of pro tempore, literally "for the time being") the actual presiding officer. By tradition, the title of President pro tempore has come to be given more-or-less automatically to the most senior senator of the majority party. In actual practice in the modern Senate, the President pro tempore also does not often serve in the role (though it is his or her constitutional right to do so), instead, as governed by the aforementioned Rule I, he or she frequently designates a junior senator to perform the function.