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NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery
Guiding Recovery of Stratospheric Ozone
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery 2
GMD plays a central role in the global effort to monitor stratospheric ozone, ozone-depleting gases, and other processes affecting stratospheric ozone
– global-to-regional scale observations to assess global changes and influences from specific processes and regions (e.g., U.S.)
– Diagnosing observed changes to clarify the relative influence of policy decisions, other human behaviors, and natural processes
– To provide the highest-quality, policy-relevant science
Guiding the recovery of the ozone layer by informing Parties to the Montreal Protocol on the progress of recovery
Our focus:
Guiding Recovery of Stratospheric Ozone at GMD
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery 3
50
100
150
200
250
300
350
400
1960 1970 1980 1990 2000 2010 2020
January Ave
21 Sep-15 Oct ave
SPO ozonesonde record
Ozo
ne T
otal
Col
umn
(DU
)
January
late September
50
100
150
200
250
300
350
400
1960 1970 1980 1990 2000 2010 2020
15 Oct - 30 Oct ave
January ave
SPO ozone, GMD Dobson O
zone
Tot
al C
olum
n (D
U)
January
late October
Stratospheric ozone depletion a threat to life on Earth.
1950s: - NOAA begins measuring total column ozone
1970s: - Theory suggesting CFCs will deplete ozone - NOAA and NASA begin measuring CFCs
1980s: - Severe ozone depletion reported in Antarctica - Montreal Protocol controls CFC production - Antarctic ozone hole attributed to CFCs and other chemicals
1990s: - US Clean Air Act Amended: NOAA and NASA to monitor: tropospheric chlorine & bromine, & stratospheric ozone depletion to project: peak chlorine the rate of chlorine decline after 2000 the date when chlorine returns to two ppb
* 1996: tropospheric chlorine peaks (NOAA-GMD publication) * 2003: tropospheric bromine peaks (NOAA-GMD publication)
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery 4
A) Measuring chemicals that cause stratospheric ozone depletion One of two global networks tracking long-term changes in ozone-depleting gases
B) Measuring long-term changes in stratospheric ozone Providing reference-quality long-term measurements of stratospheric ozone
C) Advancing scientific understanding Understanding causes of atmospheric composition change
and improving our understanding of atmospheric processes
D) Communicating results to a broader audience (stakeholders)
through simple indices, web presence, open data policies, publications, and by contributing to national and international Scientific Assessments
Guiding Recovery of Stratospheric Ozone at GMD
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery 5
•
•
ALT
BRW
KUM
SPO
NWR
MLO •
CGO
SMO
weekly hourly
• •
•
•
•
PSA
MHD
THD
SUM
Aircraft CCGG
8 km8 km8 km
Tower CCGG • •
•
• •
•
•
•
•
• •
•
• • LEF
HFM • WIS (WLG) •
+ CCGG sites
• ~ 40 chemicals measured
• Multiple techniques
• Data records up to 40 years long updated regularly on web
• Addressing global and U.S.-centric issues
A) Measuring chemicals that cause stratospheric ozone depletion
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery
220
225
230
235
240
245
250
255
260
265
2000 2005 2010 2015 2020120
140
160
180
200
220
240
260
2000 2005 2010 2015 2020
1
10
100
2000 2005 2010 2015 20205
6
7
8
9
10
11
2000 2005 2010 2015 2020
CFC-11
CH3CCl3 CH3Br
HCFC-22 ln
(ppt
) pp
t
ppt
ppt
(log scale)
NH
SH
NH
SH
NH
SH
NH SH
6
A) Measuring chemicals that deplete stratospheric ozone − Concentrations of ozone-depleting chemicals for which PRODUCTION IS
CONTROLLED by the Montreal Protocol
All major ozone-depleting gases are measured at NOAA/GMD. Emphasis is on high precision and accuracy. the better the measurement, the more one can learn…
Recent related pubs: Montzka et al., 2015; 2018; Rigby et al., 2017
See talks by S. Montzka, and by P. Yu
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery 7
0
2
4
6
8
10
12
14
16
18
2000 2005 2010 2015 2020
450
470
490
510
530
550
570
590
610
630
2000 2005 2010 2015 2020
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
2000 2005 2010 2015 2020
0
10
20
30
40
50
60
70
80
2000 2005 2010 2015 2020
CHCl3
CH2Cl2
ppt
ppt
ppt
ppt
NH
SH
NH
SH
NH
SH
NH
SH
CH3Cl
CH2Br2
Recent related pubs: Hossaini et al., 2016; 2017
Shorter-lived gases also add chlorine and bromine to the atmosphere. having human and natural sources. changing over time? Also: N2O, COS
A) Measuring chemicals that deplete stratospheric ozone − Concentrations of halogenated chemicals NOT CONTROLLED by the
Montreal Protocol, but that can influence stratospheric ozone:
See poster by G. Dutton
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery 8
14
15
16
17
1990 1995 2000 2005 2010 2015
Atm
osph
eric
Br (
ppt)
3.2
3.3
3.4
3.5
3.6
3.7
3.8
1990 1995 2000 2005 2010 2015
Atm
osph
eric
Cl (
ppb)
Decline in total Chlorine Decline in total Bromine Science 1996; Nature 1999 GRL 2003
A) Measuring chemicals that deplete stratospheric ozone − Changes in “controlled” tropospheric chlorine and bromine:
Sum of all controlled gases measured at GMD
directly addressing Congressional mandate
updated annually on NOAA web page: ftp://ftp.cmdl.noaa.gov/hats/
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery 9
556065707580859095
100
1990 1995 2000 2005 2010 2015
OD
GI
AntarcticMid-latitude
In 2017: •Antarctic ODGI was 80 •Mid-latitude ODGI was 56
Annually updated at http://www.esrl.noaa.gov/gmd/aggi/
O
zone
Dep
letin
g G
as In
dex
(O
DGI)
A) Measuring chemicals that deplete stratospheric ozone – Distilling GMD measurements of controlled gases into a single index:
The Ozone Depleting Gas Index Measuring progress in the decline of ozone-depleting halogen back to 1980 concentrations (pre-ozone hole)
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery
0
20
40
60
80
100
120
2000 2005 2010 2015 20200
2
4
6
8
10
12
2000 2005 2010 2015 2020
0.0
0.2
0.4
0.6
0.8
1.0
1.2
2000 2005 2010 2015 20200.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
2000 2005 2010 2015 2020
HFC-134a
HFC-365mfc HFC-227ea
HFC-152a
ppt
ppt
ppt
ppt
NH
SH
NH
SH
NH
SH
NH
SH
10
A) Measuring substitute Hydrofluorocarbons − Concentrations of chemicals for which PRODUCTION IS CONTROLLED by the
Montreal Protocol, but that do NOT deplete ozone
Recently added to the Montreal Protocol list of controlled substances. These results enable a tracking of radiative forcing from ODS substitution. Most substitute HFCs are measured at NOAA/GMD.
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery 11
B) Measuring long-term changes in stratospheric ozone Providing reference-quality long-term measurements of stratospheric ozone
Using a range of techniques to obtain: Ozone total column density: Dobson Brewer Ozone concentration vertical profile : Ozone Sondes (highest vertical resolution) Umkehr Ozone concentrations near Earths surface
To allow an understanding of ozone concentration changes: over time developing and applying statistical models to provide trend estimates as a function of altitude stratospheric changes (upper vs lower stratosphere) tropospheric changes (pollution-related or transported from stratosphere) as a function of latitude future ozone changes are expected to be latitude-dependent aerosol, GHGs, circulation...
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery 12
NOAA-GMD Dobson ozone program:
- Forms a global backbone of robust, calibrated total column ozone data
- Provides an essential reference for other ozone measurements (satellites, other Dobsons, etc.) through calibration transfers
- Maintains the WMO reference Dobson instrument (#D083)
NOAA-GMD ozone sonde program: - adds high vertical resolution (data were
recently homogenized) - Strengthens and augments the SHADOZ
program for tropical ozone data
Recent Dobson- and sonde-related pubs: Petropavlovskikh et al. (2015), Nair et al., 2015; Evans et al., 2016, Thompson et al., 2017, Sterling et al, (2018)
B) Measuring long-term changes in stratospheric ozone
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery
MLO
B) Measuring long-term changes in stratospheric ozone − To allow an understanding of ozone column changes by latitude (ODS+GHG+transport)
13
SPO MLO FBK+BRW
USA+OHP PTH
LDR SPO
SMO
1998-2016
1979-1997
Sept-Oct only
All data
See posters by G. McConville, K. Miyagawa
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery
B) Measuring long-term changes in stratospheric ozone - To allow an understanding of ozone column changes by altitude (ODS+GHG+transport)
14
LOTUS 2018 and Ozone Assessment 2018 used GMD data and developed statistical models to derive trends in ozone profiles and total column.
trend attribution
Boulder Umkehr, 40 km
Boulder ozonesonde, 5 km
Boulder total column
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery
B) Measuring long-term changes in stratospheric ozone – To allow an understanding of ozone column changes by altitude (ODS+GHG+transport)
15
Is ozone in lower stratosphere still decreasing? Ball et al (2018) analyses are based on satellite records
Homogenization for GMD (Sterling et al, 2018) and SHADOZ (Witte et al, 2017) ozonesonde data - improved records for future trend analyses
Oral presentation by Witte
40 %
30 %
20 %
10 %
0 %
-10 %
-20 %
-30 %
-40 % 1982 1987 1992 1996 2002 2007 2012 2017 1982 1987 1992 1996 2002 2007 2012 2017
Sonde - SBUV 25.45 - 16.06 hPa
20⁰S-20 ⁰ N
Satellite and CCMI model averaged trends (LOTUS, 2018, Ozone Assessment) - disagreement between models and observations?
Trends in the low stratosphere will be soon assessed from homogenized ozone-sonde data in tropics and middle latitudes.
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery 16
B) Measuring long-term changes in stratospheric ozone – Ozone, vertical profiles from ozone sondes on balloons
Recent related pubs: Solomon et al. 2016 – ozone-sonde detected recovery, observed in September when dynamics are quiet. Hofmann(2010)? Recovery after the September depletion rate is less than 2.7 DU/day
Pre-1971 (pre ozone-hole) Ozone-hole conditions Focus on depleted layer:
See talk by B. Johnson, poster by P. Cullis
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery 17
C) Advancing scientific understanding (Q3 & Q4 in New Research Plan) Understanding the cause of atmospheric composition changes
sources, sinks, and transport Improving our understanding of trace-gas sources and sinks Sinks: Measuring the atmospheric oxidation capacity over time budget analyses of long-lived gases
1
10
100
1992 1996 2000 2004 2008 2012 2016 2020
CH
3CC
l 3he
mis
pher
ic
mea
ns (p
pt)
NH
SH
Science 2000; Science 2011;
PNAS 2017
Inferred [OH] inter-annual changes
-20%
-10%
0%
10%
20%
30%
40% A) on [OH]G from: CH3CCl3
CH4 (constant emissions)
CH4 (v ary ing emissions)
Prinn et al. (− − −) Bousquet et al ( )
The exponential decline in CH3CCl3
M3 data
1985 1990 1995 2000 2005 2010
[OH]
var
iabi
lity
(% y
r-1)
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery
0
1
2
3
4
2.5 3.5 4.5 5.50
1
2
3
4
2.5 3.5 4.5 5.5
kinetics-only (OH) (k1/k2) = 1.8
1:1
18
C) Advancing scientific understanding (Q3 & Q4 in New Research Plan) Understanding the cause of atmospheric composition changes
sources, sinks, and transport Improving our understanding of trace-gas sources and sinks Sinks: Measuring the atmospheric oxidation capacity over time budget analyses of long-lived gases
Alternative approaches to CH3CCl3: * Deriving OH loss from consideration of hemispheric mole-fraction differences Long-lived gases (Liang et al., 2017) Short-lived gases From network and special projects (e.g., Atom)
ln(C
H 2ClC
H 2Cl)
log transform
NH
SH
ln(CH2Cl2)
latitude
CH2C
l 2 ppt
)
10
30
50
70
90
110
130
150
170
190
-90 -60 -30 0 30 60 90
0 to 4 km
4 to 8 km
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery 19
C) Advancing scientific understanding (Q3 & Q4 in New Research Plan) Understanding the cause of atmospheric composition changes
sources, sinks, and transport Improving our understanding of trace-gas sources and sinks Sources, particularly U.S. contributions, but also on a global scale
Why are CCl4 emissions continuing now that CFC production is negligible?
SPARC Report focus in 2016
What we found: US emissions are 10% of global total * associated with chemical industry * this process likely accounts for much of the remaining global emissions (Hu et al., 2016)
Other similar findings related to CFC-11 will be discussed in meeting
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery 20
C) Advancing scientific understanding (Q3 & Q4 in Research Plan) Understanding the cause of atmospheric composition changes
sources, sinks, and transport Improving our understanding of trace-gas sources and sinks
Surface measurements are influenced by variations in sources and sinks:
0
10
20
30
40
50
60
70
80
90
100
1995 2000 2005 2010 2015
Prod
uctio
n or
Em
issio
n (G
g/yr
)
Reported Production
CFC-11 Emission
Northern Hemisphere Troposphere
Southern Hemisphere Troposphere
Emission
Stratosphere
latitude al
titud
e
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery 21
• Providing expertise to national and international Assessments on Ozone and Climate: – GMD scientists have been lead authors, co-authors, contributing authors,
and contributors to these Assessments – GMD data are prominent in these Assessments
Also: •UNEP/WMO, 2018 Scientific Assessment of Ozone Depletion—lead authors •UNEP/WMO, Twenty questions and answers about the ozone layer, 2015
2014 2016 2013 2014
D) Communicating results
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery 22
Guiding ozone layer recovery in the future at GMD: • Continue ongoing programs to:
– Monitor effectiveness of the Montreal Protocol for diminishing ozone-depleting gases – Accurately measure the response of stratospheric ozone to decreasing halogen and
increasing greenhouse gas concentrations
• Especially to address newly emerging issues: – increases in CFC-11, CH2Cl2, & CH3Br; and in future for VSLS-bromine? – HFCs and Kigali Amendment – locking in climate gains from the Montreal Protocol – lower stratospheric ozone declines (Ball et al. 2018)? Assess better-positioned GMD
measurements (Unkehr; ozone-sonde)
• Add capabilities where possible: – increased sampling frequency in tropics – validation of new instruments (i.e. Pandora) – validation of new operational NOAA satellite products (i.e., IPSS)
• Participate in periodic field campaigns to: – extend an understanding of surface-based results vertically – improve process-based understanding of the atmosphere – gauge the atmospheric response to increasing greenhouse gas concentrations
NOAA/ESRL Global Monitoring Division Laboratory Review, May 21-24, 2018 Guiding Ozone Layer Recovery 23
GMD plays a central role in the global effort to monitor stratospheric ozone, ozone-depleting gases, and other processes affecting stratospheric ozone
– global-to-regional scale observations to assess global changes and influences from specific processes and regions (e.g., U.S.)
– Diagnosing observed changes to clarify the relative influence of policy decisions, other human behaviors, and natural processes
– To provide the highest-quality, policy-relevant science
Guiding the recovery of the ozone layer by informing Parties to the Montreal Protocol on the progress of recovery
Our focus:
Guiding Recovery of Stratospheric Ozone at GMD