# Presentation: 188824

## Aura Top 10 Discoveries

## OMI: SO2 emissions from smelters can be seen from space

- The Peruvian copper smelters are among the world’s largest industrial point sources of SO2.

- Ilo

- La Oroya

- Carn *et al.*, in prep

*Peru*

- Daily SO2 burdens for 3 source regions
- Sept. 2004 - June 2005

- Average OMI SO2 vertical column
- Sep 2004 - June 2005

*Equador*

*Colombia*

**Notes:**
A processing plant that separates copper from copper ore is callsed a smelter.  Copper smelters emit a lot of SO2 because copper  ore is made of copper sulfide. The smelters in Peru are among the most polluting in the world. OMI is sensitive enough to be able to identify the copper being emitted from the La Oroya and Ilo smelters even though these produce less SO2 that the volcanoes (notice that the vertical scales are different).  In addition to air quality applications, these data provide insights into the different lifetimes, dispersal etc of volcanic vs. industrial emission plumes. The SO2 plumefrom the volcanoes extends into the Pacific because the SO2 is released at a higher altitude where it has a longer atmospheric lifetime.

## OMI & MLS: First global tropospheric maps show streams of tropospheric ozone crossing the oceans

- OMI & MLS can estimate the tropospheric ozone residual by subtracting the MLS stratospheric ozone from OMI column ozone.  High residual regions correspond to pollution sources and transport

- Ziemke et al., 2006

**Notes:**
The cartoon shows how tropospheric ozone residual (TOR) is computed by subtracting the stratospheric column ozone from the total column ozone.  The stratospheric column ozone is computed using the MLS limb measurements of ozone.  The total column O3 is measured by OMI, and the TOR is the difference between them.  The monthly mean maps of the TOR show pollution streaming from the U.S., Europe and China to the west in summer and pollution from biomass burning in the equatorial zone. 

##  Coincident measurements of tropospheric ozone and carbon monoxide are critical for understanding chemical and dynamical processes.  Note the tropical high ozone coincident with CO which is associated with biomass burning.

- Carbon Monoxide

- Ozone

**TES: First Maps of Tropospheric Ozone & Carbon Monoxide**

**Notes:**
Coincident measurements of tropospheric ozone and carbon monoxide are critical for understanding chemical and dynamical processes, 
which can be very complex in the troposphere. These circles on these maps illustrate the complexity using coincident measurements for three seasons - northern hemisphere summer (JJA, top), fall (SON, middle) and winter (DJF, bottom).  During SON and DJF, areas of high tropospheric ozone are colocated with areas of high CO.  During JJA, in the tropics tropospheric ozone is high and colocated with high CO, but in the northern hemisphere, tropospheric ozone is high but is not colocated with high CO.  

## MLS: First Global Measurement of Cloud Ice in Upper Troposphere    

- Upper troposphere cloud ice from MLS, ECMWF analyses, and various other GCMs.  Note the differences over South America.
- Li et al., 2005
- Cloud ice increase with sea surface temperature >300 K leads to convective moistening of UT, and H2O feedback above that implied solely by thermodynamics
- Su et al., 2006

- Cloud ice measurement will improve global circulation models used for weather and climate forecasts.  The measurements will also help quantify the upper tropospheric (UT) hydrological cycle, including water vapor feedbacks on climate change.

**greenhouse parameter**

- ‘greenhouse parameter’ is the fraction of radiation emitted by Earth’s surface that is _not_ radiated to space

**Notes:**
The amounts of water vapor, rainfall and cloud amounts in the tropics all play a role in the Earth’s climate.  Scientists their models by comparing their results with observations, and until now, upper tropospheric cloud ice has been an “unconstrained parameters” in most climate models.  This means that different models calculate different values, but there were no observations so no one could tell if their model made sense or not.  This first measurement of global cloud ice helps us answer that question.  Note the differences between the models in the figure (especially over South America).  
The lower figure shows that cloud ice is more frequently seen over warm oceans.  Not unexpected, warm oceans lead to stronger convection and the lofting of water and ice into the upper troposphere.  The break point is near 300K SST where there is significantly more water in the upper troposphere. This additional water and ice acts as a greenhouse gas blocking radiation from escaping to space.  This slide suggests that warmer oceans will lead to more trapping of radiation leading to warmer oceans... a positive feedback.

## HIRDLS: First Maps of Sub-Visual Cirrus                    

**in the Upper Tropical Troposphere    **

-  These cirrus layers play an important role in the earth’s radiative balance as well as in dehydrating the UT/LS
-  HIRDLS observes these layers at many latitudes, 2 times each day, permitting seasonal and inter-annual variations in this critical parameter to be determined
-  Note movement from SE Asia to India to Indonesia and from Central to South America.  This movement is related to the change in the location of deep convection.

- Daily global measurements of the location, height and optical thickness of subvisible cirrus show seasonal movements

**Notes:**
MLS sees cloud ice, but HIRDLS sees the clouds themselves, even clouds that are so thin that people cannot see them.  Just as in the MLS cloud ice map we see large amounts of this cirrus in regions of significant cloud ice.  However, the HIRDLS maps show us that thin cirrus is nearly everywhere we look in the tropics but thickest near convection.

## H2O (103ppmv)

- H2O (103ppmv)

- HDO/H2O (delta-D)

- Lower HDO/H2O ratio with latitude due to condensation along with poleward transport

- High H2O and  HDO/H2O ratio over land indicates strong evapo-transpiration as the water vapor source

- Relatively Low HDO/H2O ratio with high H2O indicates re-evaporation of precipitation in tropical cloud systems

- Water isotopes trace the history of an air parcel.
- Lighter isotopes preferentially evaporate and heavier isotopes preferentially condense thus more condensation leads to more isotope depletion.
- The TES measurements show that in the tropics, re-evaporation of precipitation is an important process controlling cloud formation. Up to 70% of precipitation is re-evaporated into the cloud.

**TES: First Global Observations of HDO/H****2****O ratio  - A Tracer of Global Hydrological Processes**

- Worden et al., submitted 2006

- ~700 hPA

- ~700 hPA

**Notes:**
The hydrological cycle acts differently in different location.  This slide shows first ever measurements of HDO and water from TES.  Over Africa, HDO is high as is water suggesting rapid recycling of both HDO and water.  Over the Indian ocean, HDO is depleted even though water is high suggesting the removal of water by precipitation but not much re-evaporation.  At high latitudes, water is low as is HDO suggesting that air parcels have repeatedly lost HDO through precipitation events.

## MLS: Measurement of CO in Upper Troposphere  

- Detection of CO pollution lofted to the upper troposphere and temporarily ‘trapped’ in anticyclone over south Asia
- Filipiak et al., 2005, Li et al., 2005, Fu et al., 2006
-  Detection of ‘CO tape recorder’ in lower stratosphere which is linked to seasonal changes in biomass burning
- Reproduced by GMI chemical transport model
- Schoeberl et al., 2006

- CO Perturbation

- Rapid
- Convective
- Lifting
- of CO

- Deep Convection Zone

- Slow UT/LS Lifting of CO

**Notes:**
CO is a signature of pollution and can be transported a long way from its source.  Not surprisingly, that transport can be vertical as well as horizontal. These images show how CO detected in the lower stratosphere can tell us something about where convection is occurring.  In the upper image, the hot-spot of CO over south-east asia shows that CO is lofting into the lower stratosphere during the asian monsoon season.  Interestingly enough the hot-spot is not over the sub-continent but at the edge of the Himalayan plateau where the convection can acutlly reach higher into the stratosphere.  The lower slide shows the lofting of CO plumes into the lower stratosphere during a year and half of observations.  The variation in CO with altitude shows that convection pushes the CO to about 16 km and then it moves more slowly into the lower stratosphere - which causes the CO plumes to tilt with eight. 

## MLS: Continuous measurement of HCl in stratosphere  

- The continuous measurement of HCl in the stratosphere shows the rapid recovery of this major chlorine reservoir after polar ozone loss, and continues the long-term measurements from UARS HALOE

- First continuous view of chlorine partitioning through polar winter
- MLS simultaneously measures reservoir (HCl) and active (ClO) chlorine
- Santee et al., 2006
- Decrease in upper atmospheric HCl
- MLS global data are consistent with rate at which anthropogenic chlorine is expected to be cleansed from stratosphere
- Pre-CFC values of HCl are <2 ppbv
- Stratospheric  ‘cleansing’ will take ~50 years
- Froidevaux et al., 2006

- In the polar vortex regions HCl is converted to ClO which destroys ozone

- HCl is slowly decreasing due to ban on CFC’s

**Notes:**
When CFC’s are photolyzed, the chlorine mostly goes to form HCl.  Thus monitoring HCl tells us about ozone loss processes and the recovery of the ozone layer.  The top slide shows how HCl is converted into ozone destroying ClO (also measured by MLS) during the polar winter.  In the Antarctic ozone hole, once ozone is gone, the free chlorine reacts with methane rapidly forming  HC.  In the northern winter, not all the ozone is destroyed so the recovery to HCl is not as rapid, both HCll and ClONO2 form.  

CFCs were banned in the 1980’s so the chlorine input to the stratosphere has decreased.  The lower graph shows the slow decrease in HCl 
with time as chlorine is leaving the stratosphere.  

## MLS: First Measurement of OH in the Middle Stratosphere  

- The MLS measurements of OH and HO2 have provided the first tests of global stratospheric hydrogen chemistry and resolved the disagreement between model estimates of OH and earlier observations - these data suggest earlier observations are suspect.

- Comparison of MLS (red) with balloon (green, blue) correlative measurements and model (dashed black line) over diurnal cycle
- Pickett et al., 2006
- Comparison of MLS (red), model (black) and balloon (green) for different seasons.  There is now reasonable agreement between measurement and model values.
-    Canty et al., GRL, 2006.

**OH**

**HO****2**

**  ****0            6           12          18          24****                 local time / hour  **

**  ****0            6           12          18          24****                 local time / hour  **

**37 km**

**37 km**

**32 km**

**32 km**

**10**
**5**
**0  **

**20**
**10**
**0  **

**20**
**10**
**0  **

**20**
**10**
**0  **

**10****6**** molecules / cm****3**** **

**Notes:**
In the stratosphere there is a natural balance between production of ozone (O3) and atomic oxygen (o) by photolysis of oxygen molecules (O2) and loss of O3 and O through reactions with with radical compounds like OH and HO2.  Aura MLS is making global measurements of both OH and HO2 for the first time.  Earlier limited measurements of OH did not agree with expected values calculated from measurements of water vapor and ozone using photochemical reactions measured in the laboratory.  These measurements of OH and HO2 agree with observations.  Since profiles measured by MLS cover the globe and have already been made for more than one year, scientists can test their consistency with other measurements and the laboratory photochemical reactions at different altitudes, latitudes, time of day and seasons. Some fast photochemical reactions convert OH to HO2 and back again, and comparing the ratio of HO2/OH to its calculated value tests this very fast photochemistry.  The calculated values and the ratio vary the same way as observed by MLS, showing that scientists understand and can model this important part of ozone chemistry.

## HIRDLS: First Global Measurement of Small Scale Gravity Waves in the Stratosphere    

- The temperature cross-section (over S. America) and enlarged view (right) depicts an alternating series of + and - wave fronts propagating from mid-latitude tropopause toward the mid-stratosphere  tropics.
- This is a gravity wave with short vertical     (~ 4 km) and horizontal (500 km) wavelength and small amplitude  (1-2K) that can not be observed with other techniques.
- Analyses of HIRDLS data allow determination of momentum input from small scale waves which can be used in global circulation models.

- HIRDLS high resolution temperature measurements show short vertical wavelength gravity waves, permitting assessment of gravity wave forcing in the stratospheric circulation