# Presentation: 874228

## The SURFA Project: Reconciling in situ and Operational NWP Surface Fluxes

- C. W. Fairall1, H.-M. Zhang2, S. Smith3, E. Kent4, A. Bentamy5, R. Weller6, M. Miller7
- 1PSD3 Earth System Research Laboratory; 325 Broadway; Boulder, CO 80305
- 2NOAA NCDC;3Florida State University; 4NOC, Southhampton UK; 5IFREMER, France; 6Woods Hole Oceanographic Institution, 7ECMWF UK

**Introduction**
- Project SURFA is an initiative of the World Climate Research Programs (WCRP) Working Group on Numerical Experimentation (WGNE) and the Working Group on Surface Fluxes (WGSF). The ultimate objective of SURFA is to institutionalize the evaluation of near real-time NWP fluxes (and related fields) with high quality reference data.  During the pilot study phase the feasibility and value of this activity will be reviewed before the decision is made to develop an operational program.  If successful, the SURFA infrastructure will also be utilized to evaluate climate models with the most accurate observations available.

**2. Motivation**
- Coupled Ocean-Atmosphere climate models are subject to a variety of biases.  Fig. 1 shows an example of tropical SST and wind biases due, in part, to inadequate model representations of air-sea interactions.  SURFA hypothesis is that these interactions can be examined by comparing flux observations with operational NWP fluxes.  A example of this concept for solar flux cloud forcing is shown in Fig. 2 where two reanalysis products are compared with three independent observations in the tropical Eastern Pacific.

**References:**
- Cronin M. F., N. A. Bond, C.W. Fairall and R. A. Weller, 2006: 	Surface Cloud Forcing in the East Pacific Stratus Deck/Cold 	Tongue/ITCZ Complex, J. Climate., **19**, 392-409.
- Fairall, C. W., J. E. Hare, T. Uttal, D. Hazen, Meghan Cronin, 	Nicholas A. Bond, and Dana Veron, 2007:  Observations of 	clouds, radiation, and surface forcing in the Equatorial 	Eastern Pacific.  J. Clim., to appear.
- Wang, W., S. Saha, H.-L. Pan, S. Nadiga, and G. White, 2005: 	Simulation of ENSO in the new NCEP coupled forecast 	system model (CFS03). Mon. Wea. Rev., 133, 1574-1593.

**Contact Information:**
- C. W. Fairall
- NOAA ESRL, PSD3
- 325 Broadwayt, Boulder, CO 80305 USA
- Email: chris.fairall@noaa.gov; Phone: 303-497-3253

- Fig. 1:Annual-mean SST biases (°C) of the coupled simulations by the CFS (Wang et al. 2005).

**3. Implementation**
- SURFA will reside at the NOAA National Climate Data Center (NCDC) as a component of the NOMADS system.   Huai-Min Zhang will be the NCDC contact. Detlev Majewski (Deutscher Wetterdienst Research and Development) will be the WGNE coordinator.  Shawn Smith (FSU) will be the *in situ* data coordinator.

- Fig. 2: Cloud forcing as a function of latitude along 110/95 W averaged for October 1999-2003.  The symbols for measurements are: TAO buoys – circle, NOAA ship data – square, ISCCP – right pointing open triangle, mean of these three - solid red line.  The symbols for the reanalysis products are:  NCEP2 – left pointing triangle, and ERA40 – star (Cronin et al., 2006; Fairall et al. 2007).

**4. Model Variables and Formats**
- Both land and ocean fluxes will be archived.
**Grid:**
- All fields must be provided on a regular latitude – longitude grid at a grid spacing of 0.25° x 0.25°.
**Initial time and forecast ranges:**
- All forecasts must start at 12 UTC.  For accumulated values (where the accumulation starts at the 0-h forecast) and for instantaneous values (which are valid at the given forecast range) the following forecast ranges have to be provided: +12h, 15h, +18h, +21h, +24h, +27h, +30h, +33h, +36h.
**List of instantaneous variables**:
**List of accumulated variables (since start of the forecast):**
**List of optional variables (depending on availability)**

**Summary & Future Work:**
- *SURFA will draw heavily on the Ocean Observing Network to advance the representation of surface fluxes in numerical models.  This will have applications in operational oceanography, improvements of medium range forecasts, and parameterizations in climate models.
- *The SURFA archive will reside at NOAA/NCDC.  The model fields from ECMWF and NCEP will the archived for one year beginning in late 2007.
- *A pilot evaluation of SURFA will be done near the end of 2008.
- *The SURFA working group will recommend any changes and the rest  of the WGNE member NWP centers will be invited to participate.

**5. In Situ Data**
- Ocean fluxes will be derived from a collection buoy, VOS, and research vessel observations in coordination with OCO climate reference data project.  The SAMOS and SEAFLUX projects will cooperate.  Land fluxes will be obtained through the GEWEX LANDFLUX program (still under study).  An *in situ* data working group will be created.