The Aquarius/SAC-D Satellite Mission Gary Lagerloef Aquarius Principal Investigator South Atlantic Workshop Buenos Aires 7-10 May 2007 F. Raúl Colomb SAC-D Principal Investigator

South Atlantic Workshop May 2007, San Ceferino, Buenos Aires G. Lagerloef, Raul Colomb Salinity Mapping Satellite Mission Aquarius Salinity Microwave Instrument Launch Vehicle Service Platform and SAC-D Science Instruments Mission Operations & Ground System International Partnership between United States – Argentina Mission Partnership

South Atlantic Workshop May 2007, San Ceferino, Buenos Aires G. Lagerloef, Raul Colomb Salinity Mapping Satellite Mission NASA’s Mission Objective A Key to Studying the Global Hydrologic Cycle and Global Change Aquarius Mission is About Understanding the Interactions Between the Global Water Cycle, Ocean Circulation and Climate Through the Measurement of SSS Investigate the links between the global water cycle, ocean circulation and climate Make global, space-based measurements of Sea Surface Salinity (SSS) with high accuracy Observe and model seasonal and year- to-year variations of SSS, and how these relate to changes in the water cycle and ocean circulation Aquarius will yield an unprecedented view of ocean’s role in climate and weather A Critical Climate Parameter Missing from the Present Satellite Observing Network

South Atlantic Workshop May 2007, San Ceferino, Buenos Aires G. Lagerloef, Raul Colomb Salinity Mapping Satellite Mission CONAE’s Mission Objective The SAC-D Science Mission is About Conducting Local Measurements Over Argentina and Contributing to Global Investigations of the Atmosphere, the Oceans and the Effects of Human and Natural Processes on the Environment as Defined in the Strategic Plan of the Argentine National Space Program Validate technology for future CONAE missions Monitoring atmospheric parameters Understanding ocean circulation, global water cycle and climate interaction Monitoring environmental changes, natural hazards and sea ice Studying effect of cosmic radiation on electronic devices and characteristics of space debris SAC-D Science Mission is About Conducting Local Measurements Over Argentina

South Atlantic Workshop May 2007, San Ceferino, Buenos Aires G. Lagerloef, Raul Colomb Salinity Mapping Satellite Mission Instruments + S/P  Observatory DCS NIRST Aquarius (primary instrument) TDP SAC-D S/P CARMEN-1 (ICARE-NG & SODAD) ROSA HSC Aquarius/SAC-D Observatory MWR Microwave Radiometer New InfraRed Sensor Technology Data Collection System Radio Occultation Sounder for the Atmosphere High Sensitivity Camera Technology Demonstration Package Service Platform Mass: 1675 Kg Power:1443 W Oper. Life: 5 yrs Mass: 1675 Kg Power:1443 W Oper. Life: 5 yrs Satélite de Aplicaciones Científicas-D

South Atlantic Workshop May 2007, San Ceferino, Buenos Aires G. Lagerloef, Raul Colomb Salinity Mapping Satellite Mission InstrumentObjectivesSpecificationsResolutionOwner Aquarius Understanding ocean circulation, global water cycle and climate interaction. Soil Measures over Argentina Integrated L-band radiometers (1.413Ghz) and scatterometer (1.26Ghz) Three beams: 76 x 94, 84 x 120, 96 x 156 km NASA MWR Precipitation rate, winds peed, sea ice concentration, water vapour, clouds 23.8 and 36.5 GHz H and V pol. Bandwidth: 0.5 and 1 GHz Swath:380 km 54 km CONAE NIRST Hot spots events, sea surface temperature measurement 3.8, and  Swath: 180 km Tilt: +/-30 deg. 350 meters CONAE HSC Urban lights, electric storms, Polar regions, snow cover nm swath: greater than 700 km meters CONAE DCS Data Collection System Mhz uplink2 contacts per day with 200 platforms CONAE ROSA Atmospheric propertiesGPS Occultation TechniquesHoriz: 300 km Vert: 300 m ASI Carmen 1 ICARE and SODAD I: Effect of cosmic radiation on electronic devices S: distribution of microparticles and space debris I: three fully depleted Si and Si/Li detectors S: four SMOS sensors I: 256 channels S: Sensitivity 5 μm part at 10 km/sec CNES TDP Position, velocity and time determination Inertial angular velocity GPS receiver Inertial reference unit 20 m, 1 m/sec,.2µsec ARW: 8* deg/sqrt h CONAE Level 1 Science Objectives

South Atlantic Workshop May 2007, San Ceferino, Buenos Aires G. Lagerloef, Raul Colomb Salinity Mapping Satellite Mission Aquarius Instrument 76 x 94 km 96 x 156 km 84 x 120 km 3 Beams, 390 km swath, full coverage between adjacent orbit tracks. Primary Objective:  Understand Ocean Circulation; Global water cycle and climate interaction  Measure global SSS from space (0.2 psu rms on 150x150 km scale over ice free oceans, monthly) Instrument Description & Measurement Technique:  Sea surface brightness temperature measured by stable polarimetric radiometers operating at GHz. Salinity is derived by measuring brightness temperature at L-Band  Coincident sea surface backscattering cross-section measured by stable polarimetric scatterometer operating at 1.26 GHz. Roughness is the largest correction and is measured with the integrated L-band Scatterometer  Uses Deployable offset parabolic monolithic 2.5m reflector with three feedhorns provides three beams in a push-broom configuration  Revisit: 7 day repeat cycle  Mass: 400 kg; Power: 450 W  Operational Life: 3 years Data Products:  Derived Geo-located SSS  Time spaced averaged SSS maps Sensitivity vs Radiometer Frequency MHz Protected Band T b =εT ε = f(S, T, Freq, Incidence)

South Atlantic Workshop May 2007, San Ceferino, Buenos Aires G. Lagerloef, Raul Colomb Salinity Mapping Satellite Mission MWR Instrument Primary Objective:  Microwave Radiometer (MWR) measure surface brightness temperature in the frequency range sensitive to geophysical parameters over the ocean to contribute to climate and hydrological forecasting for the La Plata basin, Patagonia and Antarctica  MWR data complements Aquarius SSS measurements by providing 8 overlapping beams Instrument Description & Measurement Technique:  Two continuously operating radiometers at 23.8 GHz (K band; V-pol) and at 36.5 GHz (Ka band, polarimetric H & V) over land and sea (with 8 feeds per frequency)  390 km Swath width (coincident with Aquarius)  Resolution of 50 km (across-track)  Coverage: Global Precipitation Wind Speed

South Atlantic Workshop May 2007, San Ceferino, Buenos Aires G. Lagerloef, Raul Colomb Salinity Mapping Satellite Mission Simple land index derived from SSMIS 22V, 37V, 37H. Low resolution. Courtesy F. Wentz Land use Index

South Atlantic Workshop May 2007, San Ceferino, Buenos Aires G. Lagerloef, Raul Colomb Salinity Mapping Satellite Mission Data to Community Science Measurement Perspective Beams point toward the night side to avoid sun glint Beams point toward the night side to avoid sun glint Launch 2010 Launch 2010 Sun-synchronous exact repeat orbit 6pm ascending node Altitude 657 km; 98 deg inclination Earth viewing & Nadir pointing instruments Surface Validation Global Coverage in 7 Days 4 Repeat Cycles per Month Global Coverage in 7 Days 4 Repeat Cycles per Month Ground System & Data Processing Ground System & Data Processing

South Atlantic Workshop May 2007, San Ceferino, Buenos Aires G. Lagerloef, Raul Colomb Salinity Mapping Satellite Mission Orbit and Swath

South Atlantic Workshop May 2007, San Ceferino, Buenos Aires G. Lagerloef, Raul Colomb Salinity Mapping Satellite Mission Smoothing Effect of the Aquarius Footprint

South Atlantic Workshop May 2007, San Ceferino, Buenos Aires G. Lagerloef, Raul Colomb Salinity Mapping Satellite Mission 5 March 2007 Science Goal: Net Freshwater Budget Examine mean salt (SSS) advection and divergence Trial balance with E-P net surface freshwater forcing U·∇S ~ S(E-P)/H OSCAR = Geostrophic + 15m

South Atlantic Workshop May 2007, San Ceferino, Buenos Aires G. Lagerloef, Raul Colomb Salinity Mapping Satellite Mission Argo mean SSS

South Atlantic Workshop May 2007, San Ceferino, Buenos Aires G. Lagerloef, Raul Colomb Salinity Mapping Satellite Mission Net Freshwater Flux Precipitation (GPCP) & Evaporation (Lisan Yu, WHOI) H

South Atlantic Workshop May 2007, San Ceferino, Buenos Aires G. Lagerloef, Raul Colomb Salinity Mapping Satellite Mission Net flux vs Salinity divergence S(E-P)/H psu · year -1 U·∇S psu · year -1

South Atlantic Workshop May 2007, San Ceferino, Buenos Aires G. Lagerloef, Raul Colomb Salinity Mapping Satellite Mission Surface forcing minus advection Preliminary findings: Global SSS divergence patterns are of the same magnitude as E-P forcing, and thus SSS advection has a predominant role in the net surface freshwater budget. Differences between SSS divergence and (E-P)/H are of similar magnitude and are partly the result of meridional offsets of the peak latitudes. Meridional Zonal Total (E-P)/H

South Atlantic Workshop May 2007, San Ceferino, Buenos Aires G. Lagerloef, Raul Colomb Salinity Mapping Satellite Mission Education & Public Engagement Education and Public Outreach will increase awareness and understanding of how the earth functions as a system – and technology’s role in enabling development of the knowledge – through Informal and Formal Education and Professional Development activities.

South Atlantic Workshop May 2007, San Ceferino, Buenos Aires G. Lagerloef, Raul Colomb Salinity Mapping Satellite Mission 2010 A Space Odyssey