Transcript MLS: Continuous measurement of HCl in stratosphere

Aura Overview
Aura Instruments
•MLS - Operating nominally
–Band 13 electronics (HCl) are degrading rapidly due to HBT slow failure MLS will use Band 14 with occasional use of Band 13 to continue the
measurement
–Band 10 & Band 29 electronics (ClO) are degrading - seems to be a
workmanship problem; the ClO measurement can be recovered from Band 5.
•OMI - Operating nominally
• Solar measurement folding mirror anomaly has mostly been resolved.
Instrument was off for three days (Feb 28-March 2).
• TES - Operating nominally
–Increasing sign of bearing wear has caused some interruptions of
operations. TES is no longer doing routine limb mode to preserve lifetime.
• HIRDLS - Operating with reduced aperture
–A piece of Kapton® is blocking most of the optical path.
– HIRDLS teamhas developed a model of the radiance contribution from the
Kapton® piece and is beginning to produce data products
Aura Announcements
• Most of of the validation activities are behind us…
• Second validation meeting Sept. 11-15, ‘06 Boulder
• June ‘07 additional big Costa Rica mission with emphasis on
Cloudsat - CALIPSO validation DC-8, ER-2, WB-57
• AVDC is working well.
• Many new data sets are arriving to the DAAC including OMI data,
new algorithm version of MLS and TES
• HIRDLS data is coming to AVDC this month
• Special validation issue papers due date March 1, ‘07 - no delays
allowed
• Aura Science team re-propose - proposals due ~June 15, ‘07
• Exception - Recently selected OMI ST members
• Emphasis on science use and new product generation
Aura Top 10 Discoveries
OMI: SO2 emissions from smelters and volcanoes
Average OMI SO2 vertical column
Sep 2004 - June 2005
Colombia
Equador
Peru
La Oroya
Ilo
Carn et al., in prep
Ecuador/S. Colombia volcanoes
Ilo copper smelter
La Oroya copper smelter
Daily SO2 burdens for 3 source regions
Sept. 2004 - June 2005
• Daily monitoring of SO2 emissions is
possible with OMI.
• The Peruvian copper smelters are among
the world’s largest industrial point sources of
SO2.
OMI & MLS: Global Tropospheric Ozone Residual
Augmenting TES
tropospheric ozone
measurements, OMI &
MLS can produce a
tropospheric residual
product by subtracting
the MLS stratospheric
ozone from OMI
column ozone.
Ziemke et al. JGR, 2006
TES: First Maps of Tropospheric Ozone & Carbon Monoxide
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.
Ozone
Carbon Monoxide
MLS: First Global Measurement of Cloud Ice in Upper Troposphere
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
 UT cloud ice from MLS, ECMWF
analyses, and
various GCMs
 Li et al., GRL 32, L14826, 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., GRL 33, L05709, 2006
Aura MLS:
Jan 2005 mean
UCLA-Liou GCM:
5-year Jan mean
NCAR CAM3 GCM:
10-year Jan mean
ECMWF analyses:
Jan 2005 mean
GFDL-RAS GCM:
18-year Jan mean
GFDL-Donner GCM:
20-year Jan mean
convective
cloud ice


UT H2O
greenhouse
parameter
300K
300K
300K
sea surface temperature (K)
‘greenhouse parameter’ is the fraction of radiation emitted by Earth’s surface that is not radiated to space
HIRDLS: First Maps of Sub-Visual Cirrus
in the Upper Tropical Troposphere
Daily global measurements of the location, height and optical thickness of
subvisible cirrus show seasonal movements
• 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.
TES: First Observations of HDO/H2O ratio - A Tracer
of Global Hydrological Processes*
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 reevaporated into the cloud.
H2O (103ppmv)
High H2O and
HDO/H2O ratio over
land indicates strong
evapo-transpiration
water vapor source
HDO/H2O (delta-D)
~700 hPA
Relatively Low HDO/H2O
ratio with high H2O
indicates re-evaporation
of precipitation
(Diamonds) in tropical
cloud systems
Lower HDO/H2O ratio
with latitude due to
condensation along with
poleward transport
*submitted to Nature (John Worden, Kevin Bowman, David Noone, TES team members, and Christopher Webster)
~700 hPA
MLS: Measurement of CO in Upper Troposphere
 Detection of CO pollution lofted to the upper troposphere
and temporarily ‘trapped’ in anticyclone over south Asia
MLS 150 hPa CO: 25 Aug – 6 Sep 04
Filipiak et al., GRL 32, L14825, 2005
Li et al., GRL 32, L14826, 2005
Fu et al., Proc. Nat. Acad. Sci., April 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., GRL, 2006
CO Perturbation
CO deviation from mean vs. time and height
Convective
Lofting
of CO
orange is ~120 ppbv
green is ~60 ppbv
Deep
Convection
Zone
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
Santee et al., GRL 32, L12817, 2006;
Santee et al., to be submitted to JGR
 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
ppbv
ClO
2
ClO
HCl
1
01
Jun
1 Aug
HCl
1 Oct
1 Dec
1 Feb
1 Apr
In the polar vortex regions HCl is converted to
ClO which destroys ozone
3.50
Expected HCl trend
1%
pressure
/ hPa
3.45
ppbv
HCl
 MLS simultaneously measures reservoir
(HCl) and active (ClO) chlorine
3
Northern Hemisphere
lower stratosphere
(2004-05, 490K, 70-75o EqL)
Southern Hemisphere
lower stratosphere
(2005, 490K, 70-75o EqL)
3.40
 Stratospheric ‘cleansing’ will take ~50
years
MLS precision (±2σ) for monthly
global means shown here
3.35
Froidevaux et al., submitted to GRL
Jul 04
Jan 05
Jul 05
Jan 06
HCl is slowly decreasing due to ban on CFC’s
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.
OH
Pickett et al., GRL 33, L101808, 2006
Canty et al., GRL, in press
20
10
10
0
0
32 km
10
20
5
10
0
0
6
12
18
local time / hour
0
24
Dec 2004
Sep 2004
37 km
32 km
0
6
12
18
local time / hour
Mar 2005
24
Jun 2005
60
40
height / km
 Comparison of MLS (red), model (black)
and balloon (green) for different seasons.
There is now reasonable agreement
between measurement and model
values.
37 km
20
106 molecules / cm3
 Comparison of MLS (red) with balloon
(green, blue) correlative measurements
and model (dashed black line) over
diurnal cycle
HO2
0
2
4
0
2 + HO (107 cm2-3)
OH
2
4
0
2
4
60
40
0.1
1
10
1
HO2 / OH
1
0.1
1
10
HIRDLS: First Global Measurement of Small Scale
Gravity Waves in the Stratosphere
HIRDLS high resolution temperature measurements show short vertical
wavelength gravity waves, permitting assessment of gravity wave forcing in the
stratospheric circulation
The temperature cross-section (over S.
America) and enlarged view (right)
depicts an alternating series of + and wave fronts propagating from midlatitude tropopause toward the midstratosphere 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.
2008
2008
KNMI