SURFA Update on Recent Activities C W Fairall

SURFA – Update on Recent Activities C. W. Fairall, H. Zhang, Ge Peng, Scott Stevens, Andy Brown, Detlev Majewski • Background • Short review of past work • Recent new work • Plans WGNE Boulder October 2011

About SURFA (Surface Flux Analysis) • Driver: Surface processes are key in improving NWP & climate model forecast skills • Objective: SURFA is to institutionalize the evaluation of near real-time NWP (& Climate Model & Reanalysis) fluxes and related fields with high quality reference data • Interested Groups: WCRP WGSF, WGNE, GEWEX … WGNE Boulder October 2011 2

List of model variables • • Global forecast fields on regular latitude – longitude grid Resolution 0. 25° x 0. 25° Initial date: 12 UTC Forecast ranges: +12 h to +36 h, 3 -hourly Two constant fields: ORO, LSM 16 instantaneous variables: e. g. PS, ALBEDO, SEAICE, U_10 M, … 13 accumulated variables: e. g. LS_PREC, CO_PREC, SO_NET, … 3 optional variables: TH_DO_CS, SO_DO_CS, PBL_DEPTH WGNE Boulder October 2011 3

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BIG PICTURE Oceanic Near-Surface Observations Gulev et al. , Surface energy and CO 2 fluxes in the global ocean-atmosphereice system. Plenary White Paper, Ocean. Obs 2009 • Satellite – J-Ofuro, HOAPS, EFREMER, Goddard • Blended/Hybird – OAFlux (WHOI), CORE (NCAR), U. Wash. • In situ – NOAA ESRL Ship-based (40 cruises) – SAMOS Archive of R/V (20 vessels) – Ocean Sites Archive flux buoys (20 sites) – Operational TAO/PIRATA/RAMA (200 sites) – VOS/VOSCLIM Volunteer vessels (declining numbers) WGNE Boulder October 2011 5

Previous Data analysis • Preliminary study with WHOI Stratus buoy • Additionally high quality ship observations (cloud and BL observations) • Some comparisons with VOSClim (E. Kent) • Some comparisons with land fluxes (Zhang) • Seawinds (Peng) New Analyses * Ocean. Sites buoys – Peng et al. * Ship-buoy intercomparisons WGNE Boulder October 2011 6

Evaluating Global High-Resolution Remotely-sensed Ocean Surface Winds, NWP Short-Range Forecast Winds, and NCEP/CFRS Reanalysis Winds with ocean. SITES Buoy Winds Ge Peng 1, 2 , Scott Stevens 3, Huai-min Zhang 2 1 2 STG, Inc Remote Sensing and Applications Division National Climatic Data Center 3 CICS-NC Other Collaborators Jean-Raymond Bidlot: ECMWF Helmut Frank: DWD Masakazu Higaki: JMA Bill Hankins: STG, INC/NCDC WGNE Boulder October 2011 7

Data Outline • NCDC Blended Sea Winds: 6 -hourly, 0. 25 ox 0. 25 o grid, ice free ocean • NWP Winds (ECMWF, DWD, JMA): 3 -hourly, 0. 25 ox 0. 25 o grid, global • NCEP/CFSR Winds: hourly, T 382 grid, 0. 31 ox 0. 31 o at the tropics, global • ocean. SITES Winds: daily 2009, only stations with more than 75% wind measurements, adjusted to the 10 -m height assuming a logarithmic (neutral) wind profile with roughness length = 0. 15 mm This is a continuation of a previous study using three ocean. SITES TAO buoys in the equatorial Pacific (Peng et al. 2011). WGNE Boulder October 2011 8

c Red triangles are the ocean. SITES station locations that have surface wind measurements. Encircled stations are used in this extended analysis (more than 75% records existed for 2009). WGNE Boulder October 2011 9

Time Series and PSD of u & v Indian Ocean WGNE Boulder October 2011 10

Pacific Ocean WGNE Boulder October 2011 11

Atlantic Ocean WGNE Boulder October 2011 12

Bias and rms of u-comp Mean 0. 025 m/s 0. 005 m/s 0. 1696 m/s -0. 148 m/s Basin mean of all wind products 1. 45 m/s 1. 83 m/s 1. 38 m/s Mean 1. 58 m/s WGNE Boulder October 2011 13

Bias and rms of v-comp Mean -0. 02 m/s -0. 082 m/s -0. 108 m/s 0. 155 m/s Basin mean of all wind products 1. 70 m/s 1. 99 m/s 1. 45 m/s Mean 1. 74 m/s WGNE Boulder October 2011 14

Average Wind Direction and Directional Anomaly WGNE Boulder October 2011 15

Cross-Correlation for u- and v-comp Mean 0. 91 0. 936 0. 896 0. 908 Mean 0. 84 0. 914 0. 757 WGNE Boulder October 2011 0. 876 16

Summary • Improved NWP short-range winds a result of improved models and analyses assimilating satellite and buoy winds • Good correlation between various winds with in situ winds, with CFSR winds having the highest cross-correlation coefficients • In addition to the systematic bias in meridional winds found previously in equatorial Pacific stations, a smaller negative/positive bias can be seen at 8 o. S, 67 o. E /12 o. N, 23 o. W • The averaged bias values of all locations/products could give a more optimal impression – the devil is in the details WGNE Boulder October 2011 17

Future Work • Other years (2010) • Other centers (French and UK Met Offices) • Cruise winds (collaborating with Chris Fairall) WGNE Boulder October 2011 18

Ship and Flux Reference Buoys WHOTS @ 22 deg 45 N, 158 deg W NTAS @ 14 deg 50'N, 51 deg W STRATUS @ 19 deg S, 85 deg W SHOA DART @ 19 deg S, 74 deg W KEO @ 32. 25 deg N, 144 deg 30’E PAPA @ 50 deg N, 145 deg W. WGNE Boulder October 2011 19

Stratus cruise tracks WGNE Boulder October 2011 20

20˚S surface heat budget 250 200 solar flux (W m-2) 150 100 net 50 0 -50 sensible longwave -100 latent -150 -86 -84 -82 -80 WGNE Boulder October 2011 longitude -78 -76 -74 21

-80 -120 latent -40 100 sensible assess analyses and models IROAM -40 70 0 -10 -20 -30 100 85 70 -40 0 0 -25 -50 -75 -100 solar 85 0 -40 longwave October heat fluxes at 20˚S: GFDL CM 2. 1 100 85 70 -100 300 250 200 150 100 85 west longitude 150 85 70 100 85 2270 160 120 80 net Model 160 120 WHOI ORS buoy 80 WHOI (1984 -2002) analysis 40 0 CORE (1984 -2004) 100 85 WGNE Boulder October 2011 70 100 40 70 0

Wind and Temperature Comparisons Comparison of 10 -m wind speeds for Oct 2008: Upper panel – speed; middle – zonal wind; lower – meridional wind. ECMWF – green; DWD – blue; Buoy – red dots. Comparison of temperatures for Oct 2008: Upper panel – SST; lower – 10 -m air temperature. ECMWF – green; ECMWF+warm layer – magenta; DWD – blue; Buoy – red dots. WGNE Boulder October 2011 23

Ship-Buoy Intercomparisons WGNE Boulder October 2011 24

Data analysis plans (Chris Fairall) • Use all NWP sources available in archive • Focus on 6 buoys that have surface met and flux observations • Additionally high quality ship observations (cloud and BL observations) • Analysis along lines of preliminary work – means, fluxes, crude cloud variables WGNE Boulder October 2011 25

Future: NSF OOI Buoys High Latitude Emphasis WGNE Boulder October 2011 26