Transcript Natural Levels II Update.ppt

Update on Natural Levels II
Technical Review Committee
By Marc Pitchford for the
June 12th RPO Monitoring/Data
Analysis Conference Call
Overall Objective:
• To agree on a methodology that estimates the worst and
best natural conditions for each monitoring site for use
with current conditions estimated by the new IMPROVE
algorithm so that Regional Haze Rule glide paths can be
calculated in a consistent way for states that wish to use
the new algorithm.
Concerns Raised:
1.
The new IMPROVE algorithm uses concentrations in an empirical
approach to determine how much of the sulfate, nitrate, and
organic concentrations should be in the large and small size
distributions. We should assume that natural conditions have both
large and small size distributions in about the same frequency but
with (possibly) much lower concentrations.
2.
All components of aerosol extinction should be scaled to Trijonis'
natural values in a consistent manner.
3.
Use of the baseline (2000 to 2004) to estimate site specific haze
distribution functions (i.e. the standard distributions) on a site by
site basis is liable to give distortions because one of the years had
very unusual fire impacts at a number of western sites thereby
giving a false sense of the width of the distributions.
4.
We should check that the best day natural haze estimates at each
site are consistent with the current best days (i.e. they shouldn't
be larger than current best days).
Further modifications to natural
condition estimates
1. Use scattering efficiencies as prescribed by the new IMPROVE
algorithm
• natural scenario “N”
2. Test the effect of basing natural mass concentrations on current
values.
• Assume 80% of current OMC is natural
• Test the effect of using current OMC, EC, fine soil, and CM on
G90 dv natural estimates
• Look at the difference between current mean mass
concentrations and naturals estimates by aerosol species
Scenarios where individual aerosol species mass is
adjusted from natural estimates to current levels
• N – uses Trijonis east/west mass concentrations
• N1 – scale only SO4 and NO3 to estimated natural mass
concentrations (presentation 5)
• N2 – scale only SO4, NO3 and EC to estimated natural mass
concentrations (presentation 5)
• N3 – OMC adjusted to 80% of current mean
• N4 – OMC = current mean
• N5 – EC = current mean
• N6 – fine soil = current mean
• N7 – coarse mass = current mean
• N8 – fine soil and CM = current mean
• Sensitivities of scenario N to scenarios N3…N8
• Mass adjustments (current to natural estimate mean mass shifts)
Scale aerosol mass frequency distributions
Current 2000-2004
Natural Estimate
Hanging bars
Solid - current mean
Dashed - natural estimate mean
• Sipsey Alabama
• Each aerosol species
mass concentration
frequency distribution
scaled to estimated natural
mass concentrations
• If current species mean is
less than natural estimate,
the that species is not
scaled
• Geometric shape of
species distributions is
unchanged
Scaled aerosol extinction distributions
Current 2000-2004
Natural Estimate
Hanging bars
Solid - current mean
Dashed - natural estimate mean
• Sipsey Alabama
• For SO4, NO3 and OMC
use the current daily
scattering efficiencies to
calculate species extinction
(scenario Nb)
• Joint aerosol extinction
frequency distribution
shape is altered from the
current distribution
Aerosol bext and dv frequency distributions
current and scenario Nb
• Sipsey Alabama
• Natural scenario joint distribution shape is derived from scaling current
aerosol species mass concentrations to natural condition estimates
• Allows estimation of worst 20% dv or aerosol species extinction
Scenario N G90 dv
•All species adjusted to natural estimate east/west mean mass concentrations
Scenario N3 G90 dv
•All species except OMC adjusted to natural estimate east/west means
•OMC adjusted to 80% of current mean
Scenario N4 G90 dv
•All species except OMC adjusted to natural estimate east/west means
•OMC = current mean
Scenario N5 G90 dv
•All species except EC adjusted to natural estimate east/west means
•EC = current mean
Scenario N6 G90 dv
•All species except fine soil adjusted to natural estimate east/west means
•fine soil = current mean
Scenario N7 G90 dv
•All species except CM adjusted to natural estimate east/west mean
•CM = current mean
Scenario N8 G90 dv
•All species except fine soil and CM adjusted to natural estimate east/west mean
•Fine soil and CM = current mean
Sensitivity of G90 dv: scenario N to N3
•G90 dv change – increase OMC from natural estimate to 80% of current levels
Sensitivity of G90 dv: scenario N to N4
•G90 dv change – increase OMC from natural estimate to current levels
Sensitivity of G90 dv: scenario N to N5
•G90 dv change – increase EC from natural estimate to current levels
Sensitivity of G90 dv: scenario N to N6
•G90 dv change – increase fine soil from natural estimate to current levels
Sensitivity of G90 dv: scenario N to N7
•G90 dv change – increase CM from natural estimate to current levels
Sensitivity of G90 dv: scenario N to N8
•G90 dv change – increase CM and Soil from natural estimates to current levels
5-yr baseline vs. long-term estimates
scenario Nb
Difference in
2000-2004
worst 20% dv
natural
estimate
1988-2004
Site
Param
n
g90
ng90
n
g90
ng90
DG90
DG90%
DnG90
DnG90%
ACAD1
BADL1
dv
dv
568
568
23.1
17.2
12.8
8.5
1618
1668
24.5
17.6
13.3
8.2
-1.3
0.4
5.7
2.6
-0.6
0.2
4.3
-2.7
BAND1
dv
547
12.3
6.6
1581
12.7
6.3
0.4
3.1
0.3
-4.4
BIBE1
dv
527
17.5
7.5
1581
17.5
7.2
0.0
-0.2
0.3
-3.9
BRCA1
dv
519
11.8
7.3
1535
11.4
6.7
0.5
-4.0
0.6
-8.6
BRID1
dv
566
11.2
7.0
1618
10.9
6.9
0.3
-2.4
0.1
-1.0
CANY1
dv
533
11.3
6.8
1571
11.9
6.5
0.6
5.0
0.4
-5.1
CHIR1
dv
577
13.7
7.6
1607
13.5
7.0
0.2
-1.2
0.5
-7.1
DENA1
dv
549
10.0
7.4
1588
10.7
8.0
0.7
6.5
-0.6
7.8
GLAC1
dv
509
20.5
9.8
1630
20.1
9.2
0.4
-2.1
0.5
-5.6
GRSA1
dv
558
13.0
7.0
1659
12.3
6.6
0.6
-4.9
0.5
-6.8
GRSM1
dv
566
30.2
12.2
1554
31.4
12.5
1.2
4.1
-0.3
2.3
GUMO1
dv
512
17.3
7.0
1535
16.2
6.6
1.1
-6.6
0.4
-5.7
MEVE1
dv
528
13.3
7.5
1571
12.1
6.7
1.2
-9.0
0.8
-10.3
MORA1
dv
552
18.3
9.2
1585
20.4
9.5
2.1
11.5
-0.3
3.5
PEFO1
dv
513
13.7
7.0
1507
13.1
6.4
0.6
-4.4
0.6
-8.4
PINN1
dv
524
18.6
8.4
1575
19.7
8.7
1.1
6.1
-0.3
3.8
REDW1
dv
525
18.6
14.2
1595
19.9
14.5
1.3
6.8
-0.3
2.3
SHEN1
dv
537
29.6
12.2
1525
30.7
12.3
1.1
3.8
-0.1
1.1
TONT1
dv
535
14.5
7.0
1512
14.6
6.7
0.1
0.7
0.2
-3.5
WEMI1
dv
543
10.5
6.5
1585
10.7
6.4
0.2
2.3
0.1
-2.0
YOSE1
dv
521
18.0
8.6
1575
17.8
8.2
0.2
-1.3
0.4
-4.4
Status/Next Steps
• Status:
– The “N” approach (current baseline values scaled to
Trijonis average natural species concentrations and
using the new algorithm extinction without
adjustments) is the most defensible of the
approaches tried.
– The use of current (or 80% of current) OMC as
natural may be justifiable for many sites, but is
beyond the committee’s purview and time frame.
• Next Steps:
– Present material to larger audience
– Document it for further dissemination and review
Appendix
Maps of the difference between current
species concentrations and natural levels.
aSO4: mass adjustment
(Current – natural estimate) mean mass concentration difference
aNO3: mass adjustment
(Current – natural estimate) mean mass concentration difference
OMC: mass adjustment
(Current – natural estimate) mean mass concentration difference
EC: mass adjustment
(Current – natural estimate) mean mass concentration difference
Soil: mass concentration adjustment
(Current – natural estimate) mean mass concentration difference
CM: mass adjustment
(Current – natural estimate) mean mass concentration difference
Sea Salt: mass adjustment
(Current – natural estimate) mean mass concentration difference