# Presentation: 509959

## The Afternoon ConstellationAqua, CALIPSO, Cloudsat, PARASOL, AuraThe “A” Train

**The Afternoon Constellation****Aqua,**** ****CALIPSO****, Cloudsat, PARASOL, Aura****The “A” Train**

- Mark Schoeberl
- NASA/GSFC

- Acknowledgements: Graeme Stevens, Bruce Wielicki, Chip Trepte

## The Aqua/Aura Afternoon Constellation

**The Aqua/Aura Afternoon Constellation**

**The “A” Train**

## Cloudsat will  “orbit”CALIPSO,

**Cloudsat will  “orbit”CALIPSO,**
**both loosely following Aqua**

**CALIPSO Control Box**

**Aqua**
**Cloudsat**
**CALIPSO**
**PARASOL**
**Aura**

## Aqua

** ****Sun - synchronous, polar **
** ****Altitude - 705 km nominal **
** ****Inclination - 98.2 +/- 0.1 degrees **
** ****Ascending node - 1:30 p.m. +/- 15 minutes **
** ****Period - 98.8 minutes**
** ****Launched - May 4, 2002 **

**Instruments**

- Atmospheric Infrared Sounder (AIRS)
- Advanced Microwave Sounding Unit (AMSU)
- Humidity Sounder for Brazil (HSB)
- Advanced Microwave Scanning Radiometer-EOS (AMSR-E)
- Clouds and the Earth's Radiant Energy System (CERES)
- Moderate Resolution Imaging Spectroradiometer (MODIS)

## CALIPSO(formerly Picasso-CENA)

-   2-wavelength (532 and 1064 nm) polarization-sensitive LIDAR that provides 30 m vertical resolution profiles of aerosols and clouds.
-   Imaging infrared radiometer (IIR) that provides calibrated infrared radiances at 8.7 μ, 10.5 μ and 12 μ. These wavelengths are optimized for combined IIR/lidar retrievals of cirrus particle size.
-   High-resolution wide field camera (WFC) that acquires high spatial resolution imagery for meteorological context (620 to 670 nm).

**IIR**

**WFC**

**Laser**

**LITE measurements over convection**

**Distance**

**10**

**20**

**0**

**km**

**Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation**

## Cloudsat

- 94 GHz Cloud Profiling Radar (CPR)
-  Nadir-viewing
-  500 m vertical resolution
-  1.2 km cross-track, 3.5 km along track
-   Sensitivity: -30 to -36 dBZ

- Radar reflectivity
- Visible and near-IR radiances
- Cloud base and top heights
- Optical depth
- Atmospheric heating rates
- Cloud water content
- Cloud ice content
- Cloud particle size
- Precipitation Occurrence

**Data Products**

## PARASOL

**P****olarization and ****A****nisotropy of ****R****eflectances for ****A****tmospheric ****S****cience coupled with ****O****bservations from a ****L****IDAR**

**POLDER Instrument**

**Polarization and Directionality of the Earth's Reflectances**

**POLDER is a push broom, wide field of view, multi-band imaging radiometer/polarimeter, 114-degree wide field of view, 7km x 6km footprint.**
**A filter/polarizer wheel rotates and scans eight narrow spectral bands in the visible and near infrared (****443****, 490, 565, ****665****, 763, 765, ****865**** and 910 nm), and three ****polarization**** angles for select wavelengths.**

## Aura

**Aura**

**High Resolution Dynamics Limb Sounder (HIRDLS:USA)**
**Measures IR limb emission of trace gases and aerosols**
**Microwave Limb Sounder (MLS:USA)**
**Measures microwave limb emission of ozone destroying chemicals **
**Tropospheric Emission Spectrometer (TES: USA)**
**Down looking and limb looking measurements of air pollution**
**Ozone Monitoring Instrument (OMI: Netherlands)**
**Measures global ozone change**

**M LS**

**TES**

**OMI**

**HIRDLS**

**Direction of flight**

**Atmospheric Chemistry and Climate: Launch mid-2003 **

## “A-Train” Nadir Footprints

**Washington DC**
**USGS Map**

**2.3 km AIRS 0.4-1 ******

**“****A-Train” Nadir Footprints**

## Vertical Resolution of the “A Train”

**Vertical Resolution of the “A Train”**

**Aura**

**1.5-2**

**1.5**

**2.3**

**Aqua**

**1**

**2**

**CALIPSO**

**Cloudsat**

**0.03**

**Vertical resolution in km**

**MLS**

**HIRDLS**

**TES**

**AIRS**

**AMSU**
**HSB**

**0.5**

**Km**

## A-Train Science Aqua/ CALIPSO /Cloudsat/Parasol/Aura

**What are the aerosol types and how do observations match aerosol global emission & transport models?**
- CALIPSO aerosol height information + Aqua/MODIS & POLDER to get aerosol size distribution and composition
**How do aerosols contribute to the Earth radiation budget/ climate forcing?**
- CALIPSO aerosol height information + MODIS & POLDER size distributions + Aqua CERES for Earth Radiation budget
**How does cloud layering effect the Earth Radiation budget?**
- Cloudsat + CALIPSO + MODIS provides cloud height and thickness information; CERES provides Earth Rad. Budget
**What is the role of Polar Stratospheric Clouds in ozone loss and denitrification of the Arctic vortex?**
- CALIPSO + Aura/HIRDLS cloud height measurement + Aura MLS Ozone, Temperature, HNO3 and ClO
**What is the vertical distribution of cloud water/ ice in cloud systems?**
- Cloudsat + Aura/MLS + Aqua/HSB & AMSR/E

## “A” Train Correlative Measurements

**AIRS/HSB/AMSU and MLS - upper tropospheric water vapor **
**MLS: Upper tropospheric O****3****, H****2****O, Cirrus ice - 1.5 km vertical resolution ~ 7.5minutes behind Aqua  (fraction of ppm accuracy)**
**HIRDLS 22.5 minutes behind- upper trop. down to cloud tops, 1 km vertical res.**
**MODIS, PARASOL and OMI - aerosols and clouds**
**PARASOL gets polarization from different angles which can be used to identify aerosol types**
**OMI gets UV absorbing aerosols (smoke, dust and sulfates)**
**MODIS gets small and large aerosol concentration**
**HIRDLS and CALIPSO**
**HIRDLS makes limb IR aerosol measurements with vertical resolution of 1.5 km**
**CALIPSO makes aerosol measurements to 30m**
**TES and AIRS - Spectral information**
**TES: Spectral Coverage 3.2 - 15.4 ********m, 0.025 cm****-1**** resolution**
**AIRS: Spectral Coverage 3.4 - 15.4  ********m, resolution ~1 cm****-1**

## Summary of the “A” Train

**The Formation**
**Aqua (1:30 PM )and Aura (1:38 PM)) must maintain groundtrack on the WRS (±20 km) using frequent burns (once every 3 months) **
**Cloudsat and ****CALIPSO**** ~20 seconds (~140 km) behind Aqua within a control box 40 seconds wide.  Near end of mission, ****CALIPSO**** drifts (left) across MODIS swath.**
**PARASOL is roughly lined up Aqua about 3 minutes behind **
**Aura is 15 minutes behind Aqua (crossing time is 1:38 PM)**
**The Science**
**Unprecedented cloud science**
**Unprecedented climate/aerosol/chemistry science**
**Correlative measurements**
**Challenges **
**Variety of vertical and horizontal resolutions which will be challenging to match **

## Backup

## Formation Flying with Aqua

**Formation Flying with Aqua**

- Equator

**172 km**

**~2500 km**

**~2500 km**

**MODIS 1150 km**

**MLS Limb track**

**OMI swath is larger than MODIS or AIRS**

**Orbit Plane**

**Aura and Aqua have different WRS paths. **

**Cloud Sat**

**CALIPSO**

- N

**Aqua**

**Ground track**
**(WRS Path)**

**TES Limb track**

**197 km**

**73 km**

**373 km**

**~394 km**

**Airs 825 km**

**Aura**

**CALIPSO/Cloudsat ~2 minutes behind Aqua **
**Parasol is 3 minutes behind Aqua**

**PARASOL**

**7 min**
**(~ 26****o**** lat)**

**15 min**
** ****(~ 52****o**** lat)**

**7 min**

**1000 km               2000km **
**           ****HIRDLS scan**

**OMI 1300 km**

**TES Limb track**

## Aqua’s  Temperature and Moisture Sounding Suite

**AMSU (Temperature and moisture profiles)**
- 15 discrete channels in the range of 50 to 89 GHz

**AIRS (Temperature & moisture profiles, cloud properties)**
- 2,300 spectral channels in the range of 0.4 to 1.7 μ  and 3.4 to 15.4 μm

**HSB (Moisture profiles)**
- 5 discrete channels in the range of 150 to 183 MHz

**AMSR/E (Cloud properties, precipitation, total moisture) **12 channels at six discrete frequencies in the range of 6.9 to 89 GHz

**MODIS (Cloud and aerosol properties etc.)**
- 36 spectral bands from 0.4 to 14 μm

**CERES (Radiant energy flux)**
- Two sensor, one scanning cross track, the other scanning azimuthally view in three channels per scanner: shortwave (0.3 to 5 μm), longwave (8 to 12 μm), and "total" (0.3 to > 50 μm)