1Satellite Oceanography:from Concept to Implementation and LaunchYi [email protected] 818-354-81682A brief history about my long science career• 1980-85, B.S. Atmospheric Physics, University of Science & Technology of China• 1985-87, M.A., Geophysical Fluid Dynamics, Princeton University• 1987-90, Ph.D., Atmospheric and Oceanic Sciences, Princeton University• 1990-93, Postdoctoral Fellow, UCLA Dept. of Atmospheric and Oceanic Sciences• 1993-present, Jet Propulsion Laboratory, California Institute of Technology– Scientist (1993-96), Research Scientist (1997-2004), Principal Scientist (2005-present)– Supervisor of Ocean-Atmosphere Interaction group (2005-06), Deputy Manager for Earth Remote Sensing Science Section (2006-07)• 2006-present, Adjunct Professor, UCLA Dept. of Atmospheric and Oceanic Sciences & Joint Institute for Regional Earth China---19801980-851985-901990-present3JPL is known as sending Rovers to Mars4DevelopmentOperationalJason-1(2001)ACRIMSAT(1999)CloudSat(2006)QuikSCAT(1998)GRACE(2002)AIRS(2002)ASTER(1999)MISR(1999)TES(2004)MLS(2004)Carbon Cycle: Orbiting Carbon Observatory (OCO)(2008)Sea Surface Salinity: Aquarius(2009)Ocean Surface Topography Mission (2008)JPL’s Mission to Planet Earth10 missions/instruments in operations; ~600 active engineers/scientists Columbia Supercomputer, 10,240 Intel Itanium®2, SGI®NUMAflex™architecture, Linux operating system, 440 terabytes online, 10 petabytestape5------ OUTLINE ------• History of Satellite Oceanography• Overview of Present and Future Satellite Missions– Sea surface temperature– Sea surface topography (or sea level)• Theory/Method (how to measure?)• Application Examples (how to use the data?)• Aquarius sea surface salinity satellite– From concept to implementation and launch• Summary and concluding remarks6Satellite Oceanography or Satellite Remote Sensing• Remote Sensing: any technique which measures the ocean remotely without actually sampling it, or putting instruments in the water. • In addition to satellite oceanography, remote sensing includes measuring from land-based platforms, airplanes or by acoustic methods (tomography)7In Situ Observations:Early Sea Exploration (1873-1914)Challenger Expedition•226 feet, 3.5 years•362 stations, 68,890 nautical miles•100+ scientists, 29,500 pages report8Modern In Situ Observations:World Ocean Circulation Experiment (1990-2002)9Why Do We Measure Ocean from Space?It is impossible to measure the global ocean from in situ platforms • Ship operations are limited to relatively calm conditions; however, many interesting processes occur in those places that make ship operations impractical (e.g., winter time in the Labrador Sea)•In situ measurements over a large area (e.g., basin to global scale) can be expensive, and impractical (satellite measurements can be simultaneously over large areas or even the global ocean)101stWeather (Meteorological) Satellite(1960)111stOceanographic Satellite(1978)1770 Benjamin Franklin (postmaster) collected information about ships sailing between New England and England, counting dolphin populations (located near the fronts), discovering and mapping the Gulf StreamSatellite’sview of the Gulf Stream12Global Ocean Observing System from Space:Golden Age of Satellite OceanographyAVHRRTMI, AMSRGOESAquarius (2009)TOPEX/PoseidonJasonOSTM (2008)SeaWiFSMODISQuikSCATTRMMGPM (2010)13Sea Surface Temperature Satellites14How to Measure Sea Surface Temperature from Space• Physics: Blackbody radiation– Through molecular motion, all substances above absolute zero emit radiation (e.g., thermal infrared)B(λλλλ, T)=2εεεεhc2/ {λλλλ5[exp(hc/kT λλλλ)-1]}15Blended Satellite and In SituSST(Weekly for Climate Applications)16New Technology: Microwave SST Imager seeing through clouds17Ocean Surface Topography (Sea Level) Satellite18How to Measure Sea Level from Space?Satellite Altimetry830 miles, 4 miles/sec10-day repeatAccuracy < 2 inches19Application Examples: Tracking Global Sea Level RiseIPCC-200120Ocean Winds Satellites21Tracking Hurricanes with Satellites22Sea Surface Salinity Satellite:from concept to implementation and launch Planning:NeedsCommunityAcademyBudgetScheduleFormulation:ConceptTheoryDesignTestIterationsImplementations:Cut-metalBuild ComponentsTestIntegrationTestPeer-reviewsLaunch:OperationData returnAnalysisScienceApplicationsEducation23I (We the oceanographers) have a dream!24Salinity affects water density that drives ocean circulation It is gravity!(hot air rises; heavy water sinks)25Salinity is a missing piece of the climate puzzle: Melting ice changes ocean salinityAt high latitudes, salinity determines the density and controls the sinking of waterSpeedup/slowdown of the “conveyor belt” will impact weather & climate26Earth Water Cycle is Constantly Changing: Ocean’s Response to Hurricane RainHurricane Isabel (2003) accumulation of rainfall as measured by TRMM satellite. Over 400 trillion tons of freshwater were dumped on the North Atlantic Ocean during this event.27How to Measure Salinity from Space?Find an engineer to find out howTb= e Te = EmissivityT = Physical Temperaturee = function ( freq, S, T )= 1 - R2= 1 - [(1-√ε)/(1+√ε)]2 (normal incidence)ε = Relative DielectricConstant= ε(freq, S, T)28How do you know theory works? First test in the controlled environment JPL Salt Water Pond Measurements20 25 30 35 40 45120125130135140SSS (p su)Tant (K)Oct 28 K&S ModelL-Band Vertical (20-40 psu at 26 C)Input f ile: D :\PA LSTe s t\O ct1\10282 029r. sm r20 25 30 35 40 4 56870727476788082SSS (ps u)Tant (K)Oct 28 K&S ModelL-Band Horizontal In put f ile: D :\PAL STes t\O c t1\10282029r.s mrPond Size: 3.7 x 4.3 x 0.1 m29Aircraft Test the Concept: Looking for the big signalGulf Stream field experiment, 199930Instrument being mounted on top of the back door of the C-130 aircraft, which flies at 10,000 feet with the back door open.2000 & 2003 Monterey ExperimentsTest what you fly:The same configuration to be used in space31How do we know the accuracy of remotely-sensed salinity? Ground truth from ship37 37 .1 37.2 37.3 37.4323334353637La titude (de g)Salinity (PSS)Sh ip S SS S S S R etri evalFishing Boat being rented for a 2-day cruise@ 5K/dayTaking water samples from a pipe/pumpand run through a conductivity sensorProject Scientist at sea: exciting moment at a fishing break32Proposal, Funding, & ImplementationAquariusinstrument