Post on 04-Aug-2020
transcript
How can Ocean Color help Marine Managers? • The color of coastal waters can tell us much about water quality
• Satellite Ocean Color Data is a good source of water quality information
• Of the many Ocean Color products, two are most commonly used for
monitoring water quality: • Chlorophyll-a (Chl-a) is the most commonly used parameter for
monitoring phytoplankton biomass and nutrient status (i.e. productivity), as an index of water quality.
• Kd(490) is the diffuse attenuation coefficient at 490nm (or light blue in the visible spectrum) and is a good measure of the total organic and inorganic matter held in solution and suspension (i.e. turbidity) within the water column.
Climatology (Normals): Chlorophyll-a (2012-2015) E. Caribbean Overview: Red box: 12-22 °N, 60-70 °W
Point A – 10km x 10km Guánica Virtual Station
Used for Puerto Rico Climatology 17.92347 °N, 66.90108 °W
Climatology = Average of all Monthly means from Jan 2012 to Aug 2015 (Our definition of “normal” expected levels)
20N
15N
70W 65W 60W
VIIRS Target Site (A) – Guánica Watershed outfall area 10km x 10km – Water pixels only
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0.1
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3 ½ Year Monthly mean Time-series
chl-a
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0.01
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2011
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2012
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2012
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k(490)
10 Km around Point A (17.92347 °N, 66.90108 °W) Target Site: Guánica watershed discharge site
Chl-a
(m
g/m
3 )
K d(49
0) (
m-1
)
Date Format (YYYYMM)
Tropical Storm Cristobal - > 5in @ La Parguera Tropical Storm Bertha
Large Nov Rain event - ~ 5in @ La Parguera
Chlorophyll-a --- Chl-a ---
Depth-integrated attenuation coefficient – Kd(490) (“turbidity”)
--- Kd(490) (mean: 0.052)
Kd(490)
Chl-a
--- Chl-a (mean: 0.316)
Aug 2014 Anomaly Images
Kd(490) anomaly Chl-a anomaly
Nov 2014 Anomaly Images
Kd(490) anomaly Chl-a anomaly
- 0.05 0.05 - 0.5 0.5 0 0 Chl-a (mg/m3) Kd(490) (m-1)
Red Box (circle) = Target A Guánica Watershed Outfall
Comparing monthly imagery of Kd(490) and Chl-a against the
expected Normal levels (mean)
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0.05
0.1
0.15
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0.25
0.3
Monthly Mean Time-series
chl-a
0.02
0.025
0.03
0.035
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0.045
0.05
k(490)
Large 10 x 10 degree average in box (12-22 °N, 60-70 °W) Ch
l-a (
mg/
m3 )
K d(
490)
(m
-1)
Date Format (YYYYMM) Summer Max
Winter Min
Chl-a
--- Chl-a (mean: 0.161)
--- Kd(490) (mean: 0.036)
Kd(490)
Aug 2014
Kd(490) : Aug 2014 minus Climatology Chl-a: Aug 2014 minus Climatology
0.5
VIIRS Monthly Anomalies Expanded Area (August: typically highest levels)
0 -0.05 0.05 0 -0.5
Regional View of Anomalies for most of Eastern Caribbean Basin
Reports of Potential Sargassum Invasion: 2014 & 2015
“Climatology” = Expected Normal condition for all months (Jan2012-Aug2015)
Kd(490) anomaly (m-1) chl-a anomaly (mg/m3)
Nov 2014
Kd(490) : Nov 2014 minus Climatology Chl-a: Nov 2014 minus Climatology
0 -0.05 0.05 0 -0.5 0.5
VIIRS Monthly Anomalies Expanded Area (November: typically average levels)
Kd(490) anomaly (m-1) chl-a anomaly (mg/m3)
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2013
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2013
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2014
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Geo
-Pol
ar B
lend
ed 5
km N
ight
-Onl
y SS
T An
alys
is (°
C)
SST
SST (mean: 27.96)
Date Format (YYYYMM)
Additional Information
NESDIS/STAR’s 5 km Geostationary-Polar Blended Satellite Sea Surface Temperature (SST) Time Series for
Point A, Guánica Virtual Station (17.92347 °N, 66.90108 °W)