# Presentation: 657294

## The Earth’s Ozone Shield protects all life 

- The Earth’s Ozone Shield protects all life
- The Earth’s Air Quality is fundamental to public health and ecosystems
- The Earth’s Climate is affected by changes in atmospheric composition
**Aura is designed to answer questions about changes in our life-sustaining atmosphere**

## Slide 2

## Formation flying in the “A” Train

## Microwave Limb Sounder (MLS)Science Objectives

***upper tropo-spheric water vapor ***

**Track recovery of the ozone layer **
**Track chlorine and bromine ****that destroy ozone**
**Closely diagnose the Arctic, ****where ozone loss may get ****worse before it gets better**
**Resolve issues in hydrogen ****chemistry, which dominates****ozone destruction at highest &****lowest altitudes in stratosphere **
**Understand aspects of how composition affects climate **** **
**Especially processes that control****water vapor in upper troposphere:****~8-15 km (~5-10 miles) high**
**Water vapor at these heights  ****can either amplify or attenuate ****the climate effects of other ****greenhouse gases, depending ****upon the process**
**Quantify aspects of pollution in the **_**upper**_** troposphere**
**ozone, carbon monoxide, hydrogen cyanide, methyl cyanide**

## MLS on Aura is an advanced follow-on to MLS on the Upper Atmosphere Research Satellite (UARS) launched in 1991 
advanced technology enables new measurements of many important chemical species    
Contains sensitive ‘radio receivers’ that ‘listen to’ natural microwave signals emitted by molecules   
detects signals down to 10-18 Watt  (“millionth of a millionth of a millionth of a Watt”) to measure trace amounts of key chemicals 
Can measure chemicals in the presence of ice clouds and aerosols that degrade other measurement techniques
needed to quantify some important processes affecting climate variability and ozone recovery

**advanced technology enables new measurements of many important chemical species    **
**Contains sensitive ‘radio receivers’ that ‘listen to’ natural microwave signals emitted by molecules   **
**detects signals down to 10****-18**** Watt  (“millionth of a millionth of a millionth of a Watt”) to measure trace amounts of key chemicals **
**Can measure chemicals in the presence of ice clouds and aerosols that degrade other measurement techniques**
**needed to quantify some important processes affecting climate variability and ozone recovery**

**The MLS Instrument**

## Early Results from MLS (1)

**Below -  multiple constituent measurements in the Antartic Ozone hole region - note the HCL “hole” that has already developed**

**Above  -  first measurement of OH in the middle stratosphere**

## Microwave Limb Sounder: 

**Development of the Antarctic Ozone Hole 2004**

## Early Results from MLS (2)

**Below -  Detection of Cirrus Ice consistent with AIRS cirrus measurements**

**Above  -  upper tropospheric water vapor (215 mb)**
**Right - detection of BrO, HO****2**** and HOCl**

## Tropospheric Emission Spectrometer (TES)

- TES is designed to make unique measurements from space of several tropospheric gases including ozone and carbon monoxide.

**The troposphere is the part of the atmosphere where we live. Ozone near the surface is a primary pollutant, higher up it creates OH which *****removes***** pollutants, near the tropopause it is a greenhouse gas and in the stratosphere it blocks out UVB radiation.**

- TES measurements will address scientific issues such as:
*- global assessment of pollution flow*
*- chemical reactions that “cleanse” the atmosphere*
*- the coupling of climate change and atmospheric chemistry*
*     **	**	*
*     **	*

- TES extends local ground-based measurements to a global scale.

## From TES we will learn about the sources and sinks of pollutants and how they are transported on a global scale

-  Fourier transform spectrometer
-  Wavelength response: 5 to 15.4 micron
-  One scan every 4 or 16 secs
-  Four optically-conjugated 1x16 pixel detector arrays
-  Spatial resolution of 5 x 8 km at nadir & 2.3 km at limb
-  Actively cooled
-  2-axis gimbaled pointing mirror

**SIDE-LOOKING (limb)**
**provides much better measurements of the height of the gases but views a larger area and therefore clouds are much more of a problem.**

**DOWN-LOOKING (nadir)**
**is best for looking at small areas (and finding gaps in the clouds) and is also better for obtaining gas concentrations close to the surface.**

## Early Results from TES Nadir Measurements

## Tropospheric Emission Spectrometer: 

**Tropospheric Emission Spectrometer: **
**South Atlantic Pollution Plume**

**TES made the first synoptic measurement of a pollution plume in the South Atlantic. **

## High Resolution Dynamics Limb Sounder(HIRDLS)

- Figure from J.Holton/UGAMP

**Science Objectives**

-  Observe and understand exchange of chemically and radiatively active species between the troposphere and stratosphere.
-  Observe and understand the processes maintaining the distributions of ozone, water vapor, aerosols, and other gases critical to the radiative balance of Earth (Climate Change).
-  Observe and understand the distributions of ozone and the species that control its abundance, to understand its changes with time (Ozone recovery)
-  Observe the distributions of several chemically important trace species in the upper troposphere     (Air Quality)

**High Resolution Dynamics Limb Sounder(HIRDLS)**

- HIRDLS

**Notes:**
This slide shows the major design drivers

1st  line:  numbers are for desired percentage accuracy, but limited at very low levels
2nd line:  max. acceptable numbers for this unwanted effect, again lim. At low levels
3rd line:  ditto
4th line:  desired random and systematic RELATIVE pointing uncertainty limits
5th line:  ditto - systematic only
6th & 7th lines:  max. desired error in knowledge at any point on profile.

## HIRDLS

**HIRDLS**
**Instrument Features**

**Cooler For**
**Long Life**

**HIRDLS is a 21 channel IR**
**limb scanner jointly developed**
**by the US and the UK **
**HIRDLS scans both vertically and horizontally.**

- Normal limb sounder

## Ozone Monitoring Instrument (OMI)

**Ozone Monitoring Instrument (OMI)**

***OMI Science objectives*****:***** ***
**Monitor predicted global ozone recovery**
**Map UV radiation, aerosols and trace gases that contribute to poor air quality **
**Collect data to quantify the role of aerosols and tropospheric ozone on climate**

**OMI**

**OMI is a hyperspectral wide swath ultraviolet and visible imaging spectrometer**
**A contribution to the Aura mission from the Netherlands and Finland.  The science team is joint with US.**

## OMI Technology

**UV and VIS backscatter instrument measures: Column O****3****, NO****2****, SO****2****, HCHO, BrO, OClO, and Aerosols**
**Wide swath telescope yields daily global coverage maps**
**Resolution (12x24 km) is best ever for urban scale air quality measurements from space**
**Continues the highly regarded TOMS data set with additional capabilities**

## Early Results from OMI

- OMI Total Ozone on Aug 21, 2004

- EP/TOMS Total Ozone on Aug 21, 2004

**Early Results from OMI**

## Preliminary Results

-  MLS - Operating nominally
- OMI - Operating nominally
-  TES - Operating nominally - with periodic cool downs for outgassing
-  HIRDLS - A piece of kapton is apparently blocking the optical path.  This material was blown through the instrument during outgassing.  Part of the earth can be viewed from one side of the scan.  Data from HIRDLS is TBD.