The document discusses operational biogeochemical modeling in the Arctic by TOPAZ, an ArcMFC forecasting system. It describes the current and future states of TOPAZ's operational forecasting system and biogeochemical reanalysis efforts. The current forecasting system has 12km resolution and forecasts for 10 days, while the future 2021 system will have 6km resolution and include carbon chemistry variables and runoff from Greenland. The current reanalysis covers 2007-2010 at 30km resolution, and future reanalyses aim to cover 2007-2017, assimilating more biogeochemical variables using EnKF and smoothing methods.

1. Annette Samuelsen, Caglar Yumruktepe, Tsuyoshi Wakamatsu and
Laurent Bertino, NERSC; Ute Daewel, HZG; Arne Melsom, MET
Norway
O p e r a t i o n a l b i o g e o c h e m i c a l
m o d e l i n g i n t h e A r c t i c

2. B i o m o d e l p r o d u c t s
TOPAZ: The ArcMFC forecasting
system

3. B i o m o d e l p r o d u c t s
Forecasting system - present
Ocean model: HYCOM ~12 km resolution
Biogeochemical model: ECOSMO ~12 km resolution
Assimilations: As in the physical forecast – physical variables only
River runoff: Climatology from hydrological model
River nutrient load: Annual values from a global model
Forecast length: 10 days

4. B i o m o d e l p r o d u c t s
Biogeochemical model
Operational since April 2017

5. B i o m o d e l p r o d u c t s
0o
15o
E 30o
E 45o
E
64o
N
68o
N
72
o
N
76
o
N
80o
N
50
100
150
200
250
300
350
M o d e l e v a l u a t i o n :
h i n d c a s t
In-situ observations (colorscale -
day of year):
Observed annually:
Nutrients (Si, Pho, N)
Chlorphyll
Oxygen
Salinity
Temprature

6. B i o m o d e l p r o d u c t s
M o d e l e v a l u a t i o n :
h i n d c a s t v s . c l i m a t o l o g y

7. B i o m o d e l p r o d u c t s
M o d e l e v a l u a t i o n : r e a l - t i m e
http://cmems.met.no/ARC-
MFC/V2Validation/chlA/index.h
tml

8. B i o m o d e l p r o d u c t s
• Nitrate
• Silicate
• Phosphate
• Oxygen
• Chlorophyll
• Phytoplankton biomass
• Light attenuation
• Gross primary production
• Flux of organic matter to the sea floor
• Zooplankton biomass
C h e m i c a l & b i o l o g i c a l v a r i a b l e s
i n t h e f o r e c a s t
C
o
n
f
i
d
e
n
c
e

9. B i o m o d e l p r o d u c t s
Forecasting system – future (2021)
Ocean model: HYCOM ~6 km resolution
Biogeochemical model: ECOSMO ~6 km resolution
Both physical and biogeochemical model nested into the global operational
model.
River runoff: HYPE + runoff from Greenland
River nutrient load: Annual values from a global model
Model includes atmospheric nutrient deposition.
Assimilation: Nudging towards satellite derived chlorophyll, No physical
assimilation
Products will include carbon chemistry (pH, ALK, pCO2)
Forecast length: 10 days

10. B i o m o d e l p r o d u c t s
Biogeochemical reanalysis –
present (pilot)
Ocean model: HYCOM ~30 km resolution
Biogeochemical model: NORWECOM ~30 km resolution
Assimilations: Temperature, salinity, chlorophyll (EnKF)
Joint state-parameter estimation.
River runoff: Climatology from hydrological model
River nutrient load: Annual values from a global model
Reanalysis period 2007-2010

11. B i o m o d e l p r o d u c t s
Joint state-
parameter
estimation
Assimilated,
temerature,
salinity and
ocean color

12. B i o m o d e l p r o d u c t s
Assimilating
physics only
Assimilating
physics +
chlorophyll
Evalu ation of
rean alysis
again st
independent
obser vation s

13. B i o m o d e l p r o d u c t s
Biogeochemical reanalysis - future
Ocean model: HYCOM ~30 km resolution
Biogeochemical model: ECOSMO ~30 km resolution
Assimilations: Chlorophyll, nitrate, phosphate, silicate, no
temperature and salinity
Using EnKF + smoother
Joint state-parameter estimation.
River runoff: Climatology from hydrological model
River nutrient load: Annual values from a global model
Reanalysis period 2007-2017
0o
15o
E 30o
E 45o
E
64o
N
68o
N
72o
N
76o
N
80o
N
50
100
150
200
250
300
350

14. B i o m o d e l p r o d u c t s
Validation results – updated reanalysis
(Barents Sea)