Obtaining routine vertical profiles of aerosol distribution worldwide: why, how, and what to do with all that data Judd Welton GEST/UMBC & Code 912 CALIPSO.

Obtaining routine vertical profiles of aerosol distribution worldwide: why, how, and what to do with all that data Judd Welton GEST/UMBC & Code 912 CALIPSO Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations Collaborators: MPLNET: James Campbell, Tim Berkoff, Jim Spinhirne, Brent Holben, Si-Chee Tsay GLAS: Dennis Hlavka, Bill Hart, Steve Palm, Ash Mahesh, Jim Spinhirne CALIPSO: Chris Hostetler, Mark Vaughan, Ali Omar, Dave Winker, John Reagan, Tad Anderson … and a long list of other folks at NASA Centers: GSFC, LaRC, and Ames. As well as other government agencies such as ARM and NOAA. Finally, many university research groups around the world.

Outline: Introduction: why do we care about aerosols & their vertical distribution? How to measure aerosol vertical distributions? - Lidar: what is it? how to use it to study aerosols, and what can be done now to get routine global observations? MPLNET, GLAS, CALIPSO: what are they? Recent results from MPLNET, expected results from GLAS and CALIPSO, and how they can work together Conclusion

EARTH SCIENCE ENTERPRISE MISSION, GOALS, AND OBJECTIVES Develop a scientific understanding of the Earth system and its response to natural and human-induced changes to enable improved prediction of climate, weather, and natural hazards for present and future generations. 1. Science Observe, understand, and model the Earth system to learn how it is changing and the consequences for life on Earth. 2. Applications Expand and accelerate the realization of economic and societal benefits from Earth science, information, and technology. 3. Technology Develop and adopt advanced technologies to enable mission success and serve national priorities.

EARTH SCIENCE ENTERPRISE MISSION, GOALS, AND OBJECTIVES Develop a scientific understanding of the Earth system and its response to natural and human-induced changes to enable improved prediction of climate, weather, and natural hazards for present and future generations. 1. Science Observe, understand, and model the Earth system to learn how it is changing and the consequences for life on Earth. 2. Applications Expand and accelerate the realization of economic and societal benefits from Earth science, information, and technology. 3. Technology Develop and adopt advanced technologies to enable mission success and serve national priorities. One Planet

EARTH SCIENCE ENTERPRISE MISSION, GOALS, AND OBJECTIVES Develop a scientific understanding of the Earth system and its response to natural and human-induced changes to enable improved prediction of climate, weather, and natural hazards for present and future generations. 1. Science Observe, understand, and model the Earth system to learn how it is changing and the consequences for life on Earth. 2. Applications Expand and accelerate the realization of economic and societal benefits from Earth science, information, and technology. 3. Technology Develop and adopt advanced technologies to enable mission success and serve national priorities. One Planet LandAtmosphereWater

EARTH SCIENCE ENTERPRISE MISSION, GOALS, AND OBJECTIVES Develop a scientific understanding of the Earth system and its response to natural and human-induced changes to enable improved prediction of climate, weather, and natural hazards for present and future generations. 1. Science Observe, understand, and model the Earth system to learn how it is changing and the consequences for life on Earth. 2. Applications Expand and accelerate the realization of economic and societal benefits from Earth science, information, and technology. 3. Technology Develop and adopt advanced technologies to enable mission success and serve national priorities. One Planet LandAtmosphereWater Gases CloudsAerosols Plasmas

EARTH SCIENCE ENTERPRISE MISSION, GOALS, AND OBJECTIVES Develop a scientific understanding of the Earth system and its response to natural and human-induced changes to enable improved prediction of climate, weather, and natural hazards for present and future generations. 1. Science Observe, understand, and model the Earth system to learn how it is changing and the consequences for life on Earth. 2. Applications Expand and accelerate the realization of economic and societal benefits from Earth science, information, and technology. 3. Technology Develop and adopt advanced technologies to enable mission success and serve national priorities. One Planet LandAtmosphereWater Gases CloudsAerosols Plasmas … and it continues...

Aerosols: Dry or aqueous particles suspended in the atmosphere Size range: Aitken < 0.1  m fine mode < 1  m coarse mode > 1  m Origins: nucleation formation of sulfate typically Aitken sized sublimation deposition of nitrate onto sea-salt fine - coarse mode sizes coagulation merging of two aerosol droplets fine - coarse mode sizes surface matter sea-salt, dust, soot fine - coarse mode sizes Caused by natural and anthropogenic sources Particle Shapes vary: spheres (sulfate) irregular (dust) Lifetimes & Transport: vary depending upon origin, convection mechanism, size, hydroscopicity typically days to weeks, volcanic aerosols can be years can transport long distances (around the world)

Aerosols: Dry or aqueous particles suspended in the atmosphere Size range: Aitken < 0.1  m fine mode < 1  m coarse mode > 1  m Origins: nucleation formation of sulfate typically Aitken sized sublimation deposition of nitrate onto sea-salt fine - coarse mode sizes coagulation merging of two aerosol droplets fine - coarse mode sizes surface matter sea-salt, dust, soot fine - coarse mode sizes Caused by natural and anthropogenic sources Particle Shapes vary: spheres (sulfate) irregular (dust) Lifetimes & Transport: vary depending upon origin, convection mechanism, size, hydroscopicity typically days to weeks, volcanic aerosols can be years can transport long distances (around the world) Land use processes and surface conditions directly relate to the production of certain types of aerosols Example of aerosol interaction with other aspects of the earth system

Aerosols cont: Why do we care about them? Develop a scientific understanding of the Earth system and its response to natural and human- induced changes to enable improved prediction of climate, weather, and natural hazards for present and future generations. They have a direct effect on climate scatter and absorb radiation primarily fine and coarse mode change the amount of sunlight reaching the earth’s surface & what is reflected back to space absorption can alter heating budget They have an indirect effect on climate interaction with clouds create new clouds or modify existing ones change cloud albedos can effect precipitation From IPCC 2001 3rd Assessment Report

Aerosols cont: Why do we care about them? Develop a scientific understanding of the Earth system and its response to natural and human- induced changes to enable improved prediction of climate, weather, and natural hazards for present and future generations. They have a direct effect on climate scatter and absorb radiation primarily fine and coarse mode change the amount of sunlight reaching the earth’s surface & what is reflected back to space absorption can alter heating budget They have an indirect effect on climate interaction with clouds create new clouds or modify existing ones change cloud albedos can effect precipitation From IPCC 2001 3rd Assessment Report Above graph contains global mean forcing values …. Regional forcing can be much higher: Northern Indian Ocean INDOEX Results (direct+indirect): TOA Forcing: -5 to -15 W/m2 Surface Forcing: -15 to -35 W/m2 Atmosphere Forcing: 10 to 25 W/m2 (Ramanathan et al, JGR, 2001):

Aerosols cont: Why do we care about them? Develop a scientific understanding of the Earth system and its response to natural and human- induced changes to enable improved prediction of climate, weather, and natural hazards for present and future generations. They have a direct effect on climate scatter and absorb radiation primarily fine and coarse mode change the amount of sunlight reaching the earth’s surface & what is reflected back to space absorption can alter heating budget They have an indirect effect on climate interaction with clouds create new clouds or modify existing ones change cloud albedos can effect precipitation Indirect effect is another example of aerosols interacting with other parts of the earth system From IPCC 2001 3rd Assessment Report Above graph contains global mean forcing values …. Regional forcing can be much higher: Northern Indian Ocean INDOEX Results (direct+indirect): TOA Forcing: -5 to -15 W/m2 Surface Forcing: -15 to -35 W/m2 Atmosphere Forcing: 10 to 25 W/m2 (Ramanathan et al, JGR, 2001):

Aerosols cont: Why do we care about them? Develop a scientific understanding of the Earth system and its response to natural and human- induced changes to enable improved prediction of climate, weather, and natural hazards for present and future generations. Lets go one further, and say: “… natural and anthropogenic hazards …”

Aerosols cont: Why do we care about them? Develop a scientific understanding of the Earth system and its response to natural and human- induced changes to enable improved prediction of climate, weather, and natural hazards for present and future generations. Lets go one further, and say: “… natural and anthropogenic hazards …” Human Health Hazards Traffic Hazards

Aerosols cont: Why do we care about them? Develop a scientific understanding of the Earth system and its response to natural and human- induced changes to enable improved prediction of climate, weather, and natural hazards for present and future generations. Lets go one further, and say: “… natural and anthropogenic hazards …” Human Health Hazards: Small aerosols can enter the lungs EPA standard from 1997: particles smaller than 2.5  m as cutoff for regulation Pope et al., JAMA, 2002: Mortality rates & long-term exposure to fine particulate air pollution Each 10  g/m3 elevation in < 2.5  m aerosol concentration associated with: 4% increased risk of all-cause mortality 6% increased risk of cardiopulmonary mortality 8% increased risk of lung cancer mortality Conclusion: long-term exposure to small aerosols is important risk factor Caveat: heavily focused on “urban” type aerosols Aerosols, especially dust, can also carry microbes long distances Griffin et al., Aerobiologia, 2001: bacteria-like & virus-like particle counts in the US Virgin Islands greater during African dust events relative to clear periods

Aerosols cont: Why do we care about them? Develop a scientific understanding of the Earth system and its response to natural and human- induced changes to enable improved prediction of climate, weather, and natural hazards for present and future generations. Lets go one further, and say: “… natural and anthropogenic hazards …” Human Health Hazards: Small aerosols can enter the lungs EPA standard from 1997: particles smaller than 2.5 mm as cutoff for regulation Pope et al., JAMA, 2002: Mortality rates & long-term exposure to fine particulate air pollution Each 10 mg/m3 elevation in < 2.5 mm aerosol concentration associated with: 4% increased risk of all-cause mortality 6% increased risk of cardiopulmonary mortality 8% increased risk of lung cancer mortality Conclusion: long-term exposure to small aerosols is important risk factor Caveat: heavily focused on “urban” type aerosols Aerosols, especially dust, can also carry microbes long distances Griffin et al., Aerobiologia, 2001: bacteria-like & virus-like particle counts in the US Virgin Islands greater during African dust events relative to clear periods Human health issues and... Deposition of dust over oceans: can effect growth of certain types of phytoplankton & algae impacts the health of coral reefs both are examples of aerosols interacting with other aspects of the earth system

Aerosols cont: Why do we care about them? Develop a scientific understanding of the Earth system and its response to natural and human- induced changes to enable improved prediction of climate, weather, and natural hazards for present and future generations. Lets go one further, and say: “… natural and anthropogenic hazards …” Human Health Hazards Traffic Hazards

Aerosols cont: Why do we care about them? Develop a scientific understanding of the Earth system and its response to natural and human- induced changes to enable improved prediction of climate, weather, and natural hazards for present and future generations. Lets go one further, and say: “… natural and anthropogenic hazards …” Traffic Hazards: Reduced visibility creates hazards to both air and ground transportation USA Today, AP, 2002: Multiple highway accidents in California blamed on dust storms March 13,2002 - 2 seven car pile ups on I-15 MSNBC, AP, 2002: Smoke from Quebec forest fires effects air traffic in NY July 7, 2002 - all major airports report “smoke and haze visibility restrictions of two miles” Prospero et al, Eos Trans., 1999: Kennedy plane crash in July 1999 attributed in part to haze large-scale aerosol event occurred at same time, aerosols were at altitudes capable of effecting Kennedy’s visibility on approach for landing Ingestion of aerosols into aircraft engines has also been a concern New York City Skyline on July 7, 2002

Aerosols cont: If all those reasons don’t matter: How about “poor air quality makes the atmosphere look dirty and ugly” standard of living! Why do we care about them?

Aerosols cont: If all those reasons don’t matter: How about “poor air quality makes the atmosphere look dirty and ugly” standard of living! Of course, it makes pretty sunsets so I guess “who cares” Why do we care about them?

Aerosols cont: Ok we care about aerosols, but why their vertical distribution? Aerosol’s altitude determines where in the atmosphere they scatter and absorb sunlight Height of absorbing aerosols effects heating rate profile and analysis of some satellite data Aerosol height is required to determine altitude at which radiative forcing occurs Vertical distribution is tied to how aerosols transport from source region to elsewhere In order to transport long distances, aerosols must get high enough to offset their settling and removal by other processes along the trip To have direct health effects, transported aerosols must eventually reach the surface Column Radiation Meas. Surface Sampling Yes, dust arrives to Caribbean & USDust blows from Africa, across Atlantic

Aerosols cont: Ok we care about aerosols, but why their vertical distribution? Aerosol’s altitude determines where in the atmosphere they scatter and absorb sunlight Height of absorbing aerosols effects heating rate profile and analysis of some satellite data Aerosol height is required to determine altitude at which radiative forcing occurs Vertical distribution is tied to how aerosols transport from source region to elsewhere In order to transport long distances, aerosols must get high enough to offset their settling and removal by other processes along the trip To have direct health effects, transported aerosols must eventually reach the surface Column Radiation Meas. Surface Sampling Yes, dust arrives to Caribbean & USDust blows from Africa, across Atlantic But what happens along the way? How does it transport?

So what do we really want to know about aerosol vertical distribution? detect the presence of aerosols determine their altitude calculate their optical properties deduce their concentration determine if they interact with clouds and/or if they reach the surface figure out what type of aerosols are present find out how the aerosols got to a particular location and where they will go afterwards

So what do we really want to know about aerosol vertical distribution? detect the presence of aerosols determine their altitude calculate their optical properties deduce their concentration determine if they interact with clouds and/or if they reach the surface figure out what type of aerosols are present find out how the aerosols got to a particular location and where they will go afterwards Global Regional Case Studies Which type of study to choose? Global observations planetary climate seasonal/yearly studies regional connections Regional studies regional climate seasonal/yearly studies begin to connect case studies to big picture & assess their relevance Case studies can analyze aerosol in much more specific detail often best way to get point across, but should be done with relevance to bigger picture in mind

So what do we really want to know about aerosol vertical distribution? detect the presence of aerosols determine their altitude calculate their optical properties deduce their concentration determine if they interact with clouds and/or if they reach the surface figure out what type of aerosols are present find out how the aerosols got to a particular location and where they will go afterwards Global Regional Case Studies Which type of study to choose? Global observations planetary climate seasonal/yearly studies regional connections Regional studies regional climate seasonal/yearly studies begin to connect case studies to big picture & assess their relevance Case studies can analyze aerosol in much more specific detail often best way to get point across, but should be done with relevance to bigger picture in mind Routine, long-term, globally distributed measurements with enough spatial and temporal resolution to be of use to regional and case studies are most desired The IPCC 2001 3rd assessment report: need development and support of systematic ground-based measurements, in particular, a dramatic increase in systematic vertical profile measurements

What instruments can measure aerosol vertical distribution?

Direct sampling from aircraft Direct sampling from sonde Lidar

What instruments can measure aerosol vertical distribution? Direct sampling from aircraft Direct sampling from sonde Lidar What is best for global, routine, long-term monitoring?

What instruments can measure aerosol vertical distribution? Direct sampling from aircraft Direct sampling from sonde Lidar What is best for global, routine, long-term monitoring? Aircraft best platform for direct sample problems: not routine, not long-term, difficulty with ambient meas.

What instruments can measure aerosol vertical distribution? Direct sampling from aircraft Direct sampling from sonde Lidar What is best for global, routine, long-term monitoring? Aircraft best platform for direct sample problems: not routine, not long-term, difficulty with ambient meas. Sondes routine - yes, long-term - yes problems: hard to do aerosol sampling, same ambient issues, and resource is lost upon sampling

What instruments can measure aerosol vertical distribution? Direct sampling from aircraft Direct sampling from sonde Lidar What is best for global, routine, long-term monitoring? Aircraft best platform for direct sample problems: not routine, not long-term, difficulty with ambient meas. Sondes routine - yes, long-term - yes problems: hard to do aerosol sampling, same ambient issues, and resource is lost upon sampling Lidar routine - yes, long-term - yes lidar can provide most of the desired data listed previously

What is a lidar? an instrument that sends pulses of laser light into the atmosphere to measure an atmospheric parameter’s vertical structure many types of lidar exist - here we only discuss those used to measure aerosols (and clouds) Ground Boundary Layer Molecular Scattering Elevated Layer Lidar systems: Backscatter Raman DIAL Hyperspectral Laser

What is a lidar? an instrument that sends pulses of laser light into the atmosphere to measure an atmospheric parameter’s vertical structure many types of lidar exist - here we only discuss those used to measure aerosols (and clouds) Ground Boundary Layer Molecular Scattering Elevated Layer Lidar systems: Backscatter Raman DIAL Hyperspectral LaserReceiver

The Backscatter Lidar Equation: Raw signals are background subtracted and normalized to range, energy. Any other instrument Effects are also corrected for. Resulting equation is an uncalibrated lidar signal: where C  (extinction, and  (backscatter) are unknown. We can model molecular and ozone terms, particulate  and  are what we want to determine. To solve equation we must know the relationship between the two.

What we want is global, routine, long-term monitoring to start now Lidar requirements exists proven, relatively simple design capable of deployments for global observation - cost implication eye-safe

What we want is global, routine, long-term monitoring to start now Lidar requirements exists proven, relatively simple design can be deployed for global observations - cost implication eye-safe Backscatter lidars are easiest to build and can meet the above requirements more limited data set form basis for future deployment of more sophisticated lidars

What we want is global, routine, long-term monitoring to start now Lidar requirements exists proven, relatively simple design can be deployed for global observations - cost implication eye-safe Backscatter lidars are easiest to build and can meet the above requirements more limited data set form basis for future deployment of more sophisticated lidars What we want to know about aerosol vertical distribution: detect the presence of aerosols determine their altitude calculate their optical properties deduce their concentration determine if they interact with clouds and/or if they reach the surface figure out what type of aerosols are present find out how the aerosols got to a particular location and where they go afterwards Ground Boundary Layer Molecular Scattering

The Backscatter Lidar Equation: Ground-based example Ground Boundary Layer Molecular Scattering

The Backscatter Lidar Equation: Ground-based example Ground Boundary Layer Molecular Scattering … But a co-located sunphotometer can provide aerosol optical depth (AOT):  P Assume Sa is constant throughout the boundary layer: A modified version of the solution uses the sunphotometer AOT as a constraint. The normal process is iterated until successive values of Sa agree: Solving for backscatter and extinction Standard Fernald [Appl. Opt., 1984] type solution used,

The Backscatter Lidar Equation: Ground-based example Ground Boundary Layer Molecular Scattering co-located sunphotometer provides aerosol optical depth (AOT):  P Calculate Calibration parameter: C Calibrating the lidar

The Backscatter Lidar Equation: Ground-based example Ground Boundary Layer Molecular Scattering Net Results: Aerosol height can be determined MPL can be calibrated backscatter and extinction profiles can be calculated, along with an average Sa, for the aerosol layer extinction profile will integrate to the correct AOT, however the extinction value at any given altitude within the layer may be under-or-over- estimated due to assumption of a constant Sa

What we want is global, routine, long-term monitoring to start now Lidar requirements exists proven, relatively simple design can be deployed for global observations - cost implication eye-safe Backscatter lidars are easiest to build and can meet the above requirements more limited data set form basis for future deployment of more sophisticated lidars Two options ground-based network space-based platform

What we want is global, routine, long-term monitoring to start now Lidar requirements exists proven, relatively simple design can be deployed for global observations - cost implication eye-safe Backscatter lidars are easiest to build and can meet the above requirements more limited data set form basis for future deployment of more sophisticated lidars Two options ground-based network space-based platform CALIPSO Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations

E.J. Welton, Goddard Earth Sciences & Tech. Center NASA/GSFC, Code 912 Determining Optical Depth and Extinction from Satellite Lidars: The Missing Link --> Extinction-to-Backscatter Ratio (Sa) Much more difficult to get co-located AOT meas. Ground Boundary Layer Molecular Scattering Elevated Layer Determining Optical Depth and Extinction: Comparison between boundary and elevated layers Conclusion: Sometimes can directly calculate optical depth, extinction, and S for elevated layers -- NEVER for boundary layer If cannot directly calculate optical depth, need to guess S

Default Scenario: Lookup Table for Sa GLAS Index Functions based on: 4, 7, 11, 13 based on model from Ackermann, 1998 12 based on Welton et al., 2000 Current Efforts to improve knowledge of Sa: MPL-Net: field exps: target key regions/aerosols CALIPSO Science Team: John Reagan, compilation of all meas. Tad Anderson, in-situ meas. of Sa Ali Omar, calculate Sa from AERONET data Several other research groups worldwide E.J. Welton, Goddard Earth Sciences & Tech. Center NASA/GSFC, Code 912 Different lookup table for boundary layer and elevated layers Different lookup table for each month of the year

What we want is global, routine, long-term monitoring to start now Lidar requirements exists proven, relatively simple design can be deployed for global observations - cost implication eye-safe Backscatter lidars are easiest to build and can meet the above requirements more limited data set form basis for future deployment of more sophisticated lidars Two options ground-based network space-based platform CALIPSO Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations

The Micro-pulse Lidar Network : (MPL-Net) E.J. Welton, UMBC/GEST - NASA/GSFC, Code 912 MPL-Net: http://virl.gsfc.nasa.gov/mpl-net/ Mission: Long-term, world-wide observations of aerosol and cloud vertical structure using common instrument/data processing Funding: NASA Earth Observing System (sites/field exp), NASA SIMBIOS Program (ocean cruises) Activities: Setup new MPL-Net funded sites, co-located with AERONET sunphotometers (and BSRN radiometers) Incorporate existing Atmospheric Radiation Measurement (ARM) Program MPL sites Partner with other independent research groups interested in MPL measurements (federated network) Participate in field experiments and research cruises (connection to regional studies) Satellite Lidar Calibration/Validation: GLAS - ICESat (2002), CALIPSO - ESSP3 (2004) NASA Site Proposed NASA Site ARM Site Nat. Inst. Polar Res. Japan Proposed NRL Site Field Experiment Ship Cruise

Micro-pulse Lidar Systems (MPL) compact & semi-autonomous 523 nm wavelength PRF 2500 Hz eye-safe, output energy in µJ small FOV, no multiple scattering Transceiver: 20cm Cassegrain Telescope on top Laser Head, Detector, & Optics below Scalar Unit: Data Binning at 30, 75, 150, 300 m res Laser Power Supply: 1 W Nd:YLF Laser Diode (Doubled to 523nm on Head) Laptop Computer: Data Acquisition & Storage (1 min res) E.J. Welton, Goddard Earth Sciences & Tech. Center NASA/GSFC, Code 912

MPL-Net Data Products * uncertainties calculated for all data products listed below, except Level 0 * data files available from MPL-Net web-site for all operational products, all file formats in NetCDF * user can browse through images of all operational data products on web-site Level 0.0: Raw data, automated, download to GSFC and archived, but not available on the web-site (operational) Level 1.0: Real-time Normalized Relative Backscatter Signals (operational) Level 1.5a: Real-time Aerosol Height & Extinction Profile, Not Quality Assured (operational) Level 1.5b: Real-time Multiple Cloud Heights, Not Quality Assured (not operational, testing underway) Level 2.0a: Aerosol Height & Extinction Profile, Quality Assured (operational) Level 2.0b: Multiple Cloud Heights, Quality Assured (not operational, no testing yet) Level 3.0a: Continuous, Gridded, Multiple Cloud and Aerosol Data Products (not operational, testing on field exps) E.J. Welton, Goddard Earth Sciences & Tech. Center NASA/GSFC, Code 912

CALIPSO Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations Satellite Lidar Projects: Platform ICESat, launch date 2002 ? … 8) Mission Polar Altimetry Cloud and Aerosol Profiler Specs 532 and 1064 nm lidar 40 pulses/second, 76m vertical resolution Key Data Products cloud & aerosol layer heights, 0 - 40 km layer optical depths, extinction profiles Development and Science Teams (Lidar only) Algorithm Development: GSFC Code 912 Science Team: GSFC Code 912 Platform ESSP-3, launch date 2004 formation fly with CloudSat & Aqua Mission Cloud and Aerosol Profiler Specs 532 and 1064 nm lidar 20 pulses/second, vertical res. varies polarization meas. at 532 nm Key Data Products (still under development) cloud & aerosol layer heights, 0 - 40 km layer optical depths, extinction profiles Development and Science Teams Algorithm Development: LaRC Science Team: LaRC and International

MPL-Net Data Products * uncertainties calculated for all data products listed below, except Level 0 * data files available from MPL-Net web-site for all operational products, all file formats in NetCDF * user can browse through images of all operational data products on web-site Level 0.0: Raw data, automated, download to GSFC and archived, but not available on the web-site (operational) Level 1.0: Real-time Normalized Relative Backscatter Signals (operational) Level 1.5a: Real-time Aerosol Height & Extinction Profile, Not Quality Assured (operational) Level 1.5b: Real-time Multiple Cloud Heights, Not Quality Assured (not operational, testing underway) Level 2.0a: Aerosol Height & Extinction Profile, Quality Assured (operational) Level 2.0b: Multiple Cloud Heights, Quality Assured (not operational, no testing yet) Level 3.0a: Continuous, Gridded, Multiple Cloud and Aerosol Data Products (not operational, testing on field exps) E.J. Welton, Goddard Earth Sciences & Tech. Center NASA/GSFC, Code 912

Real-time MPL-Net Data Products: Level 1.0 - lidar signal E.J. Welton GEST/UMBC NASA/GSFC/912

Real-time MPL-Net Data Products: Level 1.0 - lidar signal Level 1.5a - extinction profiles correlated with AERONET data uncertainties are calculated for all data products E.J. Welton GEST/UMBC NASA/GSFC/912

E.J. Welton, Goddard Earth Sciences & Tech. Center NASA/GSFC, Code 912 Example Level 1.5b Results: ARM SGP Dec 11, 2001 (Multiple Cloud Heights)

(Data from existing ARM cloud height algorithm) False Positives E.J. Welton, Goddard Earth Sciences & Tech. Center NASA/GSFC, Code 912

1.00 0.75 0.50 0.25 0.00 GSFC May 1 - 4, 2001: NRB Signals Level 2.0 Calibration Values Example Level 3.0 Results: GSFC May 1 - 4, 2001

1.00 0.75 0.50 0.25 0.00 GSFC May 1 - 4, 2001: NRB Signals 0.5 0.4 0.3 0.2 0.0 0.1 Extinction Profiles (1/km) Aerosol Optical Thickness Black: MPL-Net Red: AERONET

Validation of MPL-Net Data Products (primarily extinction): Major effort on our part Essential before using MPL-Net data to validate satellite-based lidar systems Previous validation efforts (pre MPL-Net): ACE-2 (1997): NASA Ames Airborne Tracking Sunphotometer (AATS) INDOEX (1999): Co-located nephelometer/PSAP measurements (NOAA PMEL) Recent/Ongoing validation efforts: PRIDE (2000): NASA Ames Airborne Tracking Sunphotometer (AATS) SAFARI (2000): NASA Ames Airborne Tracking Sunphotometer (AATS) Cloud Physics Lidar (CPL) ACE-Asia (2001): NASA Ames Airborne Tracking Sunphotometer (AATS) Co-located nephelometer/PSAP measurements (NOAA PMEL) Airborne nephelometer/PSAP measurements (Univ Washington) AATS - B. Schmid, P. Russell, J. Redemann, J. Livingston (NASA Ames) NOAA PMEL - T. Bates, P. Quinn University of Washington - T. Anderson, S. Masonis CPL - M. McGill, D. Hlavka, B. Hart (GSFC)

Data from PRIDE 2000: Livingston et al., 2002 Data from SAFARI 2000: Schmid et al., 2002 (includes comparions with Results from the ER-2 based Cloud Physics Lidar -CPL - Also based in 912) Data from ACE2 (1997): Welton et al., 2000 Examples of Validation of MPL Extinction Profiles: Comparisons with the NASA Ames Airborne Tracking Sunphotometer (AATS)

Some Examples of Science and applications: Using MPL data to characterize aerosol regionally put together results from different regions in the network and we build global view Tying MPLNET results together with aerosol modeling and satellite data to study transport Using MPLNET as a ground calibration/validation tool for GLAS and CALIPSO

Aerosol vertical structure over the Northern Indian Ocean? Data from INDOEX 1999 --- Welton et al., JGR, 2002 Aerosol extinction, humidity, and temperature according to key air mass trajectories during the experiment

Aerosol vertical structure over the Northern Indian Ocean? Data from INDOEX 1999 --- Welton et al., JGR, 2002 Sa values recorded during the experiment in relation To other measurements over the ocean

First Year Results from GSFC site: Seasonal Study Apr 2001 - July 2002 (using level 1.5a results, not screened for bad data) Monthly averages of aerosol extinction profiles

First Year Results from GSFC site: Seasonal Study Apr 2001 - July 2002 Monthly averages of aerosol results from MPLNET & AERONET* * AERONET results from 2001 climatology

E.J. Welton, Goddard Earth Sciences & Tech. Center NASA/GSFC, Code 912 CALIPSO Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations MPL-Net Validation Efforts for Satellite Lidar Projects: MPL-Net can be used for the following: Post-launch Validation: cloud and aerosol heights layer optical depths and extinction profiles Help tackle the extinction-to-backscatter ratio (Sa) problem improve determination of Sa for specific aerosol types & geographic regions assess utility of using aerosol transport models to help infer aerosol type result then used to calculate Sa

Issues Involved in Validating Satellite Lidar Using Ground-based Lidar: Example from SAFARI: Comparison between MPL and CPL Degree of Horizontal and Temporal Homogeneity is a key factor Same applies to comparisons between Lidar and Ground/Airborne Sunphotometers (ACE-2, PRIDE, SAFARI, ACE-Asia, CLAMS)

E.J. Welton, Goddard Earth Sciences & Tech. Center NASA/GSFC, Code 912 CALIPSO Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations MPL-Net Validation Efforts for Satellite Lidar Projects: MPL-Net can be used for the following: Post-launch Validation: cloud and aerosol heights layer optical depths and extinction profiles Help tackle the extinction-to-backscatter ratio (Sa) problem improve determination of Sa for specific aerosol types & geographic regions assess utility of using aerosol transport models to help infer aerosol type result then used to calculate Sa

MPLNET Results from Various Field Experiments are being used to help determine Sa Values Southern Africa: Biomass, pollution, some dust Caribbean: Dust, sea-salt, some pollution China: Dust, some pollution Pacific, Yellow Sea, Sea of Japan: Sea-salt, dust, pollution

E.J. Welton, Goddard Earth Sciences & Tech. Center NASA/GSFC, Code 912 CALIPSO Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations MPL-Net Validation Efforts for Satellite Lidar Projects: MPL-Net can be used for the following: Post-launch Validation: cloud and aerosol heights layer optical depths and extinction profiles Help tackle the extinction-to-backscatter ratio (Sa) problem improve determination of Sa for specific aerosol types & geographic regions assess utility of using aerosol transport models to help infer aerosol type* result then used to calculate Sa * closely tied to using lidars to study aerosol transport, example shown

Default Sa Lookup Table: Aerosol type required Transport models may help identify aerosol type

E.J. Welton, Goddard Earth Sciences & Tech. Center NASA/GSFC, Code 912 Comparisons between MPLNet observations and GOCART Results: Early April 2001 - Massive Dust Storms in Asia MPL Systems Operating as part of MPLNet in April 2001 GSFC: MPL-Net Site SGP and NSA: ARM Sites Ship: R/V Ronald Brown (ACE-Asia/SIMBIOS) Dunhuang: China, ACE-Asia (S. Tsay) GOCART Dust Sources: Sah: Saharan T: Taklamakan M: Middle East G: Gobi D: Distrubed Soils (GOCART Data courtesy P. Ginoux, M. Chin) GSFC SGP NSA Dunhuang Ship Sah M TG

Image by R. Husar, Washington Univ. April 7, 2001

Dun Huang, China April 9, 2001 R/V Ron Brown Sea of Japan April 10, 2001 and …….. MPL-Net Level 1.0 Data for several sites during April 2001

GOES Imagery April 13, 2001 at 1400 UTC (image courtesy A. Chu and S. Tsay 913)

Dun Huang, China April 9, 2001 R/V Ron Brown Sea of Japan April 10, 2001 ARM Southern Great Plains Oklahoma April 13, 2001 and …….. MPL-Net Level 1.0 Data for several sites during April 2001

GSFC Data: April 13-14, 2001 (First Observation of Asian Dust at GSFC) April 14, 2001 GSFC AERONET AOD and Angstrom Exponent: April 13-14, 2001 April 13, 2001 Discontinuity in AERONET data at same time as appearance of aerosol layer at 5-6 km AOD increases by ~ 0.05 Angstrom Exponent drops below 1, indicating sudden presence of large particles

GSFC Data: April 13-14, 2001 (First Observation of Asian Dust at GSFC) April 14, 2001 GSFC AERONET AOD and Angstrom Exponent: April 13-14, 2001 April 13, 2001 Discontinuity in AERONET data at same time as appearance of aerosol layer at 5-6 km AOD increases by ~ 0.05 Angstrom Exponent drops below 1, indicating sudden presence of large particles a

Ship: Sea of Japan April 10 GSFC: April 13 Comparisons between results from MPLNET and GOCART * GOCART still shows more Saharan dust than all 3 of these sources

Conclusion: Aerosols are an important part of the earth system for studies of climate, health, and traffic hazards Determining aerosol vertical distribution is required for a complete understanding of their effects and how they transport

Conclusion: Aerosols are an important part of the earth system for studies of climate, health, and traffic hazards Determining aerosol vertical distribution is required for a complete understanding of their effects and how they transport Lidars are capable of providing information on aerosol vertical distribution At this time: the simplest type, the backscatter lidar, is best suited for coordinated global, routine, long-term measurements

Conclusion: Aerosols are an important part of the earth system for studies of climate, health, and traffic hazards Determining aerosol vertical distribution is required for a complete understanding of their effects and how they transport Lidars are capable of providing information on aerosol vertical distribution At this time: the simplest type, the backscatter lidar, is best suited for coordinated global, routine, long-term measurements Projects such as MPLNET, GLAS, and CALIPSO are capable of generating useful data on global, regional, and even case study scales

Conclusion: Aerosols are an important part of the earth system for studies of climate, health, and traffic hazards Determining aerosol vertical distribution is required for a complete understanding of their effects and how they transport Lidars are capable of providing information on aerosol vertical distribution At this time: the simplest type, the backscatter lidar, is best suited for coordinated global, routine, long-term measurements Projects such as MPLNET, GLAS, and CALIPSO are capable of generating useful data on global, regional, and even case study scales When (or if) GLAS and CALIPSO begin data collection we will enter a new stage of lidar analysis large data sets, massive spatial scales, and seemingly unending temporal coverage how to handle all that data, and work with it, is the focus of much thought

Conclusion: Aerosols are an important part of the earth system for studies of climate, health, and traffic hazards Determining aerosol vertical distribution is required for a complete understanding of their effects and how they transport Lidars are capable of providing information on aerosol vertical distribution At this time: the simplest type, the backscatter lidar, is best suited for coordinated global, routine, long-term measurements Projects such as MPLNET, GLAS, and CALIPSO are capable of generating useful data on global, regional, and even case study scales When (or if) GLAS and CALIPSO begin data collection we will enter a new stage of lidar analysis large data sets, massive spatial scales, and seemingly unending temporal coverage how to handle all that data, and work with it, is the focus of much thought To the future: if (when) these types of projects are successful and useful, then serious thought should be given to implementing more sophisticated lidars into global measurement strategies

Conclusion: Aerosols are an important part of the earth system for studies of climate, health, and traffic hazards Determining aerosol vertical distribution is required for a complete understanding of their effects and how they transport Lidars are capable of providing information on aerosol vertical distribution At this time: the simplest type, the backscatter lidar, is best suited for coordinated global, routine, long-term measurements Projects such as MPLNET, GLAS, and CALIPSO are capable of generating useful data on global, regional, and even case study scales When (or if) GLAS and CALIPSO begin data collection we will enter a new stage of lidar analysis large data sets, massive spatial scales, and seemingly unending temporal coverage how to handle all that data, and work with it, is the focus of much thought To the future: if (when) these types of projects are successful and useful, then serious thought should be given to implementing more sophisticated lidars into global measurement strategies what if the data from these more simple lidars turns out to be sufficient to answer the big questions (aerosol only)? or worse - no uses the data?

Obtaining routine vertical profiles of aerosol distribution worldwide: why, how, and what to do with all that data Judd Welton GEST/UMBC & Code 912 CALIPSO.

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Obtaining routine vertical profiles of aerosol distribution worldwide: why, how, and what to do with all that data Judd Welton GEST/UMBC & Code 912 CALIPSO.

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Presentation on theme: "Obtaining routine vertical profiles of aerosol distribution worldwide: why, how, and what to do with all that data Judd Welton GEST/UMBC & Code 912 CALIPSO."— Presentation transcript:

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