CITES-2009 CITES-2009 CONFERENCE CONFERENCE KRASNOYARSK, KRASNOYARSK, Russia Russia OBSERVING THE EARTH FROM SPACE AS AN INTEGRATED SYSTEM: THE USA/F* A-TRAIN CONCEPT G. BEGNI, D. RENAUT (CNES CNES), D. TANRE, J.PELON (CNRS CNRS) * With contributions of Canada, Brazil and Netherlands 1
RAISING THE CURTAIN THE A-TRAIN ORIGINAL CONCEPT (1) The "A-Train" satellite formation consists of seven satellites flying in close proximity : Aqua, Aura, CloudSAT, CALIPSO, PARASOL, OCO, GLORY. They cross the equator within a few minutes of one another at around 1:30 p.m. local time. By combining information observed almost simultaneously from several sources, scientists can obtain comprehensive information to better understand important parameters related to climate change. 2
RAISING THE CURTAIN THE A-TRAIN ORIGINAL CONCEPT (2) 3
AQUA Launched on May 4, 2002 K. Hokusai 4
THE AQUA MISSION Aqua mission => to collect a large amount of information about the Earth's water cycle, including evaporation from the oceans, water vapour in the atmosphere, clouds, precipitation, soil moisture, sea ice, land ice, and snow cover on the land and ice. Additional variables measured by Aqua : radiative energy fluxes, aerosols, vegetation cover on the land, phytoplankton & dissolved organic matter in the oceans, and air, land, & water temperatures. 5
THE SIX AQUA INSTRUMENTS (1) AIRS, (Atmospheric Infrared Sounder) - an advanced sounder - 2378 infrared channels & 4 visible/near-infrared channels, => highly accurate atmosphere temperature profiles & a variety of additional Earth/atmosphere products. Accuracy: 1 K temperature per 1 km layer in the troposphere. AMSU-A (Advanced Microwave Sounding Unit) - a 15-channel microwave sounder => obtain temperature t profiles in the upper atmosphere (especially the stratosphere) & provide a cloud-filtering capability for tropospheric temperature observations HSB (Humidity Sounder for Brazil) - a 4-channel microwave sounder provided by Brazil aimed at obtaining humidity profiles throughout the atmosphere even under conditions of heavy cloudiness and haze. Nadir Spatial Resolution 13.5 km => AIRS : flagship instrument in this triplet centered on measuring accurate temperature and humidity profiles throughout the atmosphere. 6
THE SIX AQUA INSTRUMENTS (2) MODIS (already on bord TERRA) TERRA & AQUA MODIS are viewing the entire Earth's surfaceevery every 1 to 2 days - 36 spectral bands or groups (0.4 µm to 14.4 µm) 250 m to 1 km ground resolution. Two CERES (Cloud and Earth Radiant Energy System) - already on board TERRA) - a 3-channel radiometer measuring reflected solar radiation (0.3-5 µm) emitted terrestrial radiation (8-12 µm) and total radiation (from 0.3 µm to beyond 100 µm). => measure the Earth's total thermal radiation budget, and, in combination with MODIS data,, detailed information about clouds (nadir spatial resolution: 20 km). AMSR (Advanced Microwave Scanning Radiometer) - a 12 channel, six-frequency passive-microwave radiometer system. Measures brightness temperatures at 6.925, 10.65, 18.7, 23.8, 7 36.5, and 89.0 GHz - 55 scan angle.
A MODIS/AQUA IMAGE Haze concentrated over Bangladesh on January 20, 2009. 8
AURA Launched on July 15, 2004 9 Ozone Hole Maximum on 2008 as evidenced by AURA, Sept. 12, 2008 NASA
AURA The AURA mission is to conduct research on the composition, chemistry and dynamics of the Earth s atmosphere. Main targets: Ozone, air quality & climate. Four instruments are implemented on board to reach this objective. 10
AURA INSTRUMENTS (1) HIRDLS : Scanning infrared limb sounder - Observes global distribution of temperature and concentrations of O3, H2O, CH4, N2O, NO2, HNO3, N2O5, CFC11, CFC12, ClONO2, and aerosols in the upper troposphere, p stratosphere, and mesosphere. MLS : Passive microwave limb-sounding radiometer /spectrometer ( millimeter and sub-millimeter) (1) stratospheric temperature and upper tropospheric constituents t that t play an important t role in stratospheric t chemistry (OH, HO2, BrO) (2) (2) upper tropospheric water vapor even in the presence of tropical cirrus, & cirrus ice content. 11
AURA INSTRUMENTS (2) OMI (contribution of Netherlands): hyperspectral imager to observe solar backscatter radiation in the visible and ultraviolet. Can distinguish between aerosol types, measure cloud pressure & coverage and such components as NO2, SO2, BrO, OClO => derive tropospheric ozone. TES: : high-resolution infrared-imaging imaging Fourier transform spectrometer => discrimination of most radiatively active molecular species in the Earth's lower atmosphere. Day- night coverage anywhere on the globe. Operates in a combination of limb and nadir mode. 12
Example: S02 concentration derived by AURA/OMI SO2 Plume from Nyamuragira Volcano (OMI SO2 Amount: avg Nov 28- Dec 4, 2006) P.I: Nikolay Krotkov & Arlin Krueger (NASA GSFC / UMBC) 13
CALIPSO Launched on April, 2006 V. Van Gogh 14
CALIPSO PHYSICS (1) CALIPSO combines CALIOP,, an active retro-diffusion lidar instrument (532 nm & 1064 nm ; polarized reception ; 20 Hz ; 1 meter diameter telescope ; 30 m vertical resolution; 333m horizontal resolution) with passive infrared (8.65 µm, 10.6 µm & 12.05 µm; 125m /1 km ground resolution) and visible (645 nm; 125 m ground resolution) imagers) => to probe the vertical structure and properties of thin clouds and aerosols over the globe. 15
CALIPSO PHYSICS (2) Retro-diffusion lidar => information about height and thickness of the clouds and aerosols layers in the atmosphere => size, shape (spherical or not) and composition (ice/water) of particles. 16
CLOUDSAT 17
CloudSat PHYSICS CloudSat and CALIPSO provide new insight into the role that clouds and atmospheric aerosols (airborne particles) play in regulating g Earth's weather, climate, and air quality. CALIPSO and CloudSat (+ AURA & PARASOL) are to evaluate some key properties of clouds and aerosols/clouds interaction. CloudSat can be seen as the microwave complement of the optical CALIPSO. 18
CloudSat INSTRUMENT CPR (Cloud Profiling Radar- developed by NASA/JPL and the Canadian Space Agency ) is a 94-GHz nadir-looking radar which measures the power backscattered by clouds as a function of distance from the radar. Physics of 94-GHz cloud sounding radars is extensively developed d and understood. d ( Rain radars ) 19
CLOUDSAT DATA EXAMPLE CloudSat nighttime overpass of the thunderstorms over Kentucky, Tennessee, and Mississippi on Feb. 5, 2008. Image credits: NASA/JPL & NCAR The convection intensity is particularly evident in the CloudSat image (large hail present in these systems): Large regions of radar attenuation =>lack of surface signal return in the image) Evidence of multiple scattering => sub-surface return). 20
PARASOL Launched on 18/12/2004 Claude Monet 21
PARASOL Parasol is a microsatellite developed by CNES carrying the wide-field imaging radiometer/polarimeter POLDER (Polarization and Directionality of the Earth s Reflectances) POLDER is designed to improve our knowledge of the radiative and microphysical properties of clouds and aerosols by measuring the directionality and polarization of light reflected by the Earth-atmosphere atmosphere system. 22
PARASOL / INSTRUMENT The POLDER instrument observes the Earth surface under several angles at specific wavelengths including polarimetric components: (nm) 444.5 444.9 492.2 564.5 670.2 763.3 763.1 907.7 860.8 Pol Y N N N Y N N N Y 23
PARASOL / MISSION (1) PARASOL mission => to characterize acte e the radiative properties of clouds and aerosols by exploiting its complementarities with the other A-Train instruments: CERES & MODIS on the AQUA satellite, the lidar on CALIPSO and the radar on CLOUDSAT, APS on GLORY. Complementarities => PARASOL ability to measure directional characteristics and polarization of emitted light. Ancillary result => measure of ground surfaces BDRF (Bidirectional Reflectance Function) 24
PARASOL / MISSION (2) PARASOL can provide: global AOD (Aerosol Optical Depth) over ocean and the fraction of AOD due to major natural a and anthropogenic components : fine mode, and a coarse mode with a combination of hydrated spherical and non spherical particles (dust). AOT (Aerosol Optical Thickness) of the fine mode over land 25
PARASOL SOME RESULTS 26
Aerosol products over Ocean: 27 August 2007 AOD 865 Effective Radius AOD fine 865 27
Aerosol products over Land: 27 August 2007 AOD Fine mode AOD Fine mode Lidar/CALIOP 28
How are aerosol particles transformed during transport? May 09, 2007 > 2.55µm May 10, 2007 2.50µm May 11, 2007 1.70µm May 12, 2007 1.50 µm Dust Event: 09-12 May, 2007 Aerosol Effective Radius 29
GLORY Under integration Reunion Island Portal 30
GLORY MISSION Glory is designed to achieve two missions: To collect data on the chemical, microphysical, i and optical properties, and spatial and temporal distributions of aerosols. To continue collection of total solar irradiance data for the long-term climate record. 31
GLORY INSTRUMENTS APS (Aerosol Polarimetry Sensor) : scanning sensor collecting VIS, NIR & SWIR data scattered from aerosols and clouds => extremely accurate multi-angle observations of Earth & atmosphere spectral polarization & radiance. TIM (Total Irradiance Monitor) : radiometer that records total solar irradiance with extreme accuracy and precision i (including l redundancies, d self calibration, sun autonomous pointing). 32
CLOUDS & AEROSOLS: SYNERGIES Provide statistics on the vertical structure of clouds around the globe (Calipso & CloudSat) Provide statistics on the geographic and vertical distribution of aerosols around the globe (Calipso, Parasol & Glory) Provide estimates t of the percentage of Earth's clouds that t produce rain (CloudSat) Detect subvisible clouds in the upper troposphere and Polar Stratospheric t Clouds (Calipso) Provide vertically-resolved estimates of how much water and ice are in Earth's clouds (CloudSat) Detect snowfall from space (CloudSat) Estimate how efficiently the atmosphere produces rain from condensates (CloudSat) Provide an indirect estimate of how much clouds and aerosols contribute to atmospheric warming (Calipso, CloudSat, 33 Aqua/Modis, Parasol, Glory)
CLOUDS & AEROSOLS: EXAMPLES 34
CLOUDS & AEROSOLS: EXAMPLES 35
OCO Launch failed early 2009. NASA actively prepares OCO-2 CO2 Kolki in Western Siberian forest V.N.Sedykh
OCO- INSTRUMENT OCO single instrument : three parallel, high- resolution spectrometers, making simultaneous measurements of the carbon dioxide id and molecular oxygen absorption of sunlight reflected off the same location on Earth's surface ( : 0.76 µm; 1.61 µm; 2.06 µm) 37
OCO- Physical principles (1) OCO measures column averaged dry air CO2 mole fraction (Xco2). Models allow to infer the location of sources and sinks. OCO measures the intensity of reflected sunlight off of the Earth's surface at specific wavelengths where the absorption level is indicative of the abundance of molecules of interest (large number of densely spaced samples to compensate detrimental effects) 38
OCO- Physical principles (2) The weak CO2 band ( ~1.61 µm) is most sensitive to the CO2 concentration near the surface. Measurements relatively clear and unambiguous. The strong CO2 band ( ~2.06 µm) provides a second and totally independent measure. Very sensitive to the presence of aerosols & variations in atmospheric pressure and humidity. Detecting and mitigating the presence of aerosols enhances the accuracy of Xco2 ( => synergy with other A-Train instruments). The O2 absorption band ( ~ 0.76 µm) provides the required reference spectra. 39
THE ORIGIN OF THE WORDING A-TRAIN A jazz song recorded by Duke Ellington and Ella Fizgerald in 1941: You must take the A-Tain To go to Sugar Hill Way up in Harlem.. If you miss the A-Train You ll find missed the quickest way To Harlem 40
THANK YOU FOR YOUR ATTENTION 41