Global high-resolution marine isoprene emission derived from VIIRS-SNPP and MODIS-Aqua ocean color observations 1/25/2016Air Resources Laboratory1 Daniel Tong, Hang Lei, Li Pan, Pius Lee NOAA Air Resources Laboratory (ARL), College Park, MD Menghua Wang NOAA Center for Satellite Applications and Research (STAR), College Park, MD Brett Gantt and Sarwar Golam US EPA Office of Research and Development Jeff McQueen and Ivanka Stajner NOAA National Weather Services Acknowledge: NOAA Joint Satellite System Proving Ground Program for funding support;

2  Oceans cover 70% of Earth’s surface, but marine emissions are highly certain;  Marine emissions play oversized roles in cloud formation in pristine environment; Isoprene (CH2=CH-C(CH3)=CH2) is a biogenic hydrocarbon emitted by trees, grasses and ocean phytoplankton. Marine Isoprene Emission  Anthropogenic emissions decreasing and ozone standards tightened  marine emissions and chemistry become increasingly important;  Marine chemistry being added to CMAQ  carefully verified emissions; There is a similar need for climate models and Earth System models.

National Air Quality Forecast over Hawaii 1/25/2016Air Resources Laboratory3  Isoprene;  Dimethyl Sulfide (DMS);  Organic Aerosols; A suite of reactive gases and aerosols emitted from the Ocean:

Algae Bloom and Ocean Cloudiness 1/25/2016Air Resources Laboratory4 (Meskhidze and Nenes, Science, 2006)

A Review of Approaches for Marine Isoprene Emissions 1/25/2016Air Resources Laboratory5  Shaw et al. (2003):  Palmer & Shaw (2005):  Gantt et al. (2009): E iso - Isoprene emission; [Chl-a] - Isoprene emission; V – euphotic water volume; EF – Emission factor; k AS – exchange coeff.; C W – isop. conc. in water H – Henry’s law constant; C A – isop. conc. in the air P – isoprene production; H max – euphotic zone height; Z ML – mixing layer height; k i – chemical reaction rate for oxidant i; k bio – bacterial loss rate; L MIX – loss due to downward mixing;

JPSS marine Isoprene algorithm (V1.0) 1/25/2016Air Resources Laboratory6  Built upon several pioneering works: I 0 – ground radiation; K490 – defuse attenuation coefficient in water JPSS Products Used:  [Chl-a]  Kd490  PAR Euphotic zone height (Gantt et al., 2009) Phytoplankton Functional Types (PFTs) (Arnold et al., 2009) Determine emission factor (EF) and abundance (f); No data available from JPSS, using SeaWiFS climatological data

7 Chlorophyll-a and K d (490)  Sensor/Satellite: Visible Infrared Imaging Radiometer Suite (VIIRS) on SNPP  Ocean Color Data Processing: - Multi-Sensor Level-1 to Level-2 (MSL12) is used for VIIRS ocean color data processing - Routine ocean color data production from SDR (Level-1B) to ocean color EDR (Level-2), and to global Level-3 data, including nL w, chlorophyll-a, and K d (490). - Level 3: Products are mapped to the CoastWatch geographic regions  Algorithms (Ocean Color EDR Team): – Chlorophyll-a concentration: VIIRS OC3 algorithm – Diffuse attenuation coefficient at 490 nm K d (490): Wang et al. (2009) algorithm Chlorophyll-a K d (490)

Global Distribution of Marine Isoprene

1/25/2016Air Resources Laboratory9 Isoprene Observations and Reprocessing Issue: Some data can not be directly used for product validation. Reprocessing Approach: Air-sea mass transfer. Convert seawater conc into flux: C W – isop. conc. in water H – Henry’s law constant; C A – isop. conc. in the air k AS – exchange coeff.; Calculate exchange coeff based on wind speed: U – surface wind speed;T – Sea surface Temperature (Wanninkhof et al., 2004)

Isoprene applications: National and regional air quality forecasting Global Isoprene (April 2014) Isoprene into CMAQ domains

Marine Isoprene Data Spatial coverage: global 4km; Temporal: hourly, daily, weekly, monthly, or yearly; Two products: 1) emission rate with GFS; 2) normalized emission with own met; Data format: 1) netCDF; 2) IOAPI; Data projection: 1) lat-lon; 2) Lambert Conformal Conic 11 Data access Forecasters – Direct data access from NOAA CMAQ and other model users – RSIG(EPA) or CMAS? University users – NSF EarthCube (PI: L. Di) Contact information:

1/25/2016Air Resources Laboratory12 Summary & Future Plan  Derived global high-resolution marine isoprene emissions;  The emission data validated with ship measurements;  Data will be made available to CMAQ users;  Future plans include adding additional trace gases and organic aerosol emissions to better capture ocean emissions into the air.