GOALS AND OBJECTIVES: RECENT ANALYSIS OF ULYSSES AND ACE IN-SITU MEASUREMENTS HAS SHOWN THAT A SIGNIFICANT PORTION OF THE SOLAR WIND SLOWER THAN 700 KM/S RETAINS THE SAME DYNAMICAL AND PHOTOSPHERIC COMPOSITIONAL PROPERTIES OF THE FAST WIND EXCEPT FOR SLOWER SPEED AND HIGHER PLASMA IONIZATION. THIS LATTER WIND HAS BEEN INTERPRETED AS FAST WIND ORIGINATING FROM THE BOUNDARIES BETWEEN CORONAL HOLES AND CLOSED MAGNETIC FIELD REGIONS ACCELERATED BY ALFVEN WAVES THROUGH THE SAME MECHANISM AS THE "NORMAL" STEADY FAST WIND. UNDER THIS PICTURE THE SLOW PATCHY WIND WITH CORONAL ABUNDANCES POSSIBLY GENERATED BY RECONNECTION OF CLOSED AND OPEN FIELD LINES IS MOSTLY CONFINED TO SPEEDS LOWER THAN 500~KM/S. THESE RESULTS HAVE LED TO A "UNIFIED WIND SCENARIO" WHICH DIVIDES THE SOLAR WIND IN TWO COMPONENTS: 1 - A WAVE-DRIVEN STEADY WIND AT ALL VELOCITIES COMING FROM CORONAL HOLES WITH PHOTOSPHERIC FE/O ABUNDANCE RATIO AND VARIABLE CHARGE STATE RATIOS; 2 - A RECONNECTION-DRIVEN PATCHY HIGHLY VARIABLE WIND SLOWER THAN 450~KM/S COMING FROM ORIGINALLY CLOSED CORONAL LOOPS WITH CORONAL FE/O ABUNDANCE RATIOS AND HIGH CHARGE STATE RATIOS. FOR THIS INTERPRETATION TO HOLD IT IS NECESSARY THAT THE CORONAL HOLE PLASMA AT OPEN/CLOSE FIELD BOUNDARIES BE DENSER HOTTER AND LESS ACCELERATED THAN AT THE HOLE CENTER IN ORDER TO PRODUCE A SLOW WIND WITH HIGH IONIZATION AND PHOTOSPHERIC ABUNDANCES. ALSO THE ROLE OF EQUATORIAL CORONAL HOLES IN THE GENERATION OF THIS FAST WIND FROM THE HOLE BOUNDARIES IS UNCLEAR AND THE EFFECT OF THE SOLAR CYCLE ON POLAR AND EQUATORIAL CORONAL HOLES AND ON THE WIND THEY PRODUCE NEEDS TO BE DETERMINED. WE PROPOSE A THREE-YEAR INVESTIGATION AIMED AT ANSWERING THE FOLLOWING QUESTIONS: 1) ARE TEMPERATURE AND DENSITY GRADIENTS PRESENT AT THE OPEN/CLOSE FIELD BOUNDARIES IN CORONAL HOLES? 2) ARE EQUATORIAL CORONAL HOLES AND THEIR WINDS CONSISTENT WITH THE UNIFIED WIND SCENARIO? 3) DO THE SOURCE REGIONS OF THE STEADY WIND IN THE UNIFIED WIND SCENARIO CHANGE WITH SOLAR CYCLE PHASE AND STRENGTH? MISSION DATA: WE WILL USE AVAILABLE HIGH RESOLUTION SPECTRA FROM CDS SUMER EIS AND IRIS TO DETERMINE THE PHYSICAL PROPERTIES OF EQUATORIAL AND POLAR CORONAL HOLES AND TO MONITOR THEIR RESPONSE TO SOLAR CYCLE STRENGTH AND PHASE FROM 1996 TO 2015 COVERING SOLAR CYCLE 23 AND HALF OF SOLAR CYCLE 24. METHODOLOGY: SPECTROSCOPIC MEASUREMENTS WILL BE CARRIED OUT USING STANDARD EUV SPECTROSCOPIC DIAGNOSTIC TECHNIQUES COMMONLY USED IN THE COMMUNITY AND DESCRIBED IN PHILLIPS ET AL. (2008 - CAMBRIDGE UNIVERSITY PRESS). RELEVANCE TO MISSIONS AND HELIOPHYSICS DECADAL SURVEY: THIS INVESTIGATION IS TIMELY AS MEASUREMENTS FROM MORE THAN ONE SOLAR CYCLE ARE NOW AVAILABLE; ALSO THIS WORK WILL PROVIDE THE OBSERVATIONAL TEST OF THE UNIFIED WIND SCENARIO WHICH HAS JUST BEEN PROPOSED; ALSO IT WILL GIVE US THE MEANS TO UNDERSTAND AND PREDICT THE SOLAR WIND ITS EFFECTS ON THE HELIOSPHERE AND ITS DEPENDENCE ON THE SOLAR CYCLE. THUS IT WILL DIRECTLY ADDRESS THE FOLLOWING HELIOPHYSICS DECADAL SURVEY GOALS: (1) "DETERMINE THE ORIGINS OF THE SUN'S ACTIVITY AND PREDICT THE VARIATIONS IN THE SPACE ENVIRONMENT"; AND (4) "DISCOVER AND CHARACTERIZE FUNDAMENTAL PROCESSES THAT OCCUR BOTH WITHIN THE HELIOSPHERE AND THROUGHOUT THE UNIVERSE". ALSO IT ADDRESSES THE GOAL COMMON ALL THE USED INSTRUMENTS TO IDENTIFY THE SOURCE OF THE SOLAR WIND.