[148] | 1 | TROPFLUX DATA README |
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| 2 | ==================== |
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| 3 | |
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| 4 | Complete information about the TropFlux project and data can be found at: |
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| 5 | http://www.locean-ipsl.upmc.fr/tropflux/ |
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| 6 | |
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| 7 | Short description of TropFlux |
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| 8 | ----------------------------- |
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| 9 | |
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[202] | 10 | The TropFlux project aims at providing daily, timely, accurate air-sea heat and momentum flux data for the entire 30°N-30°S region. Wind stresses and the four components of net surface heat flux are currently available for the entire 1979 to March 2013 period. We are currently working on a regular (~monthly) update of the TropFlux product until 3-4 months behind realtime. |
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[148] | 11 | |
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[200] | 12 | TropFlux is largely derived from a combination of ERA-I re-analysis data for turbulent and longwave fluxes, and ISCCP surface radiation data for shortwave flux. All input products are bias- and amplitude-corrected on the basis of Global Tropical Moored Buoy Array data, before surface net heat flux and wind stresses are computed using the COARE v3 bulk algorithm. A precise description of the flux computation procedure, as well as a detailed evaluation against other timely, daily air-sea heat flux alternatives (OAFLUX, NCEP, NCEP2, ERA-I) is provided in Praveen Kumar et al. 2012. The wind stress product is described, evaluated and compared against other widely used products (QuikSCAT, NCEP, NCEP2, ERA-I) in Praveen Kumar et al. 2013 |
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[148] | 13 | |
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| 14 | We believe that this product offers the following advantages: |
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| 15 | |
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| 16 | - better variability and less biases than re-analysis fluxes (and equivalent or slightly better than the best performing products: OAFLUX for heat fluxes and ERA-I for wind stresses) , |
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[202] | 17 | - available until March 2013, and soon updated every month, lagging realtime by ~3 months, |
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[148] | 18 | - a simple estimate of surface shortwave radiation is provided from OLR data, as a near-realtime alternative to the more accurate but irregularly updated ISCCP data. |
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| 19 | |
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| 20 | The TropFlux product has been developed under a collaboration between the Laboratoire d'Océanographie: Expérimentation et Approches Numériques (LOCEAN) from Institut Pierre Simon Laplace, France and National Institute of Oceanography/CSIR, India. Bilateral scientific visits to France and India have been supported by Institut de Recherche pour le Développement, France. |
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| 21 | |
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| 22 | Data format |
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| 23 | ----------- |
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| 24 | |
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| 25 | The following variables are provided: |
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| 26 | |
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| 27 | - surface net short wave radiation (swr, W/m^2, positive downward) |
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| 28 | - surface net longwave radiation (lwr, W/m^2, positive downward) |
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| 29 | - latent heat flux (lhf, W/m^2, positive downward) |
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| 30 | - sensible heat flux (shf, W/m^2, positive downward) |
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| 31 | - net air-sea flux (netflux, W/m^2, positive downward) |
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| 32 | - zonal wind stress (taux, N/m^2, positive eastward) |
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[189] | 33 | - meridional wind stress (tauy, N/m^2, positive northward) |
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[148] | 34 | - wind stress module (tau, N/m^2, positive) |
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| 35 | - wind module at 10m height (ws, m/s, positive) |
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| 36 | - Specific humidity at 2m height (q2m, g/kg, positive) |
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| 37 | - Air temperature at 2m height (t2m, degC) |
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| 38 | - Bulk sea surface temperature (sst, degC) |
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| 39 | |
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[160] | 40 | The data is provided in NetCDF format, with one file per variable for the complete dataset. |
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[148] | 41 | Daily (almost 1Gb per file) and monthly (32Mb per file) average data are proposed. |
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| 42 | The data is provided on a 1° resolution grid (with the same land-sea mask than for the OAFLUX project, http://oaflux.whoi.edu/ ). |
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[160] | 43 | There are 60 points in latitude at -29.5, -28.5, ..., 28.5 (positive north of the equator). |
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| 44 | There are 350 points in longitude at 30.5, 31.5, ..., 379.5 (eastward of the Greenwich meridian). |
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[148] | 45 | This choice on longitude has been made: to avoid including points with only land (in central Africa)and to avoid cutting through a tropical ocean. |
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| 46 | |
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| 47 | References |
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| 48 | ---------- |
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| 49 | |
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[186] | 50 | Praveen Kumar, B., J. Vialard, M. Lengaigne, V. S. N. Murty, M. J. McPhaden, 2012: TropFlux: Air-Sea Fluxes for the Global Tropical Oceans - Description and evaluation, Climate Dynamics, 38, 1521-1543, doi:10.1007/s00382-011-1115-0 |
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[148] | 51 | |
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[200] | 52 | Praveen Kumar, B., J. Vialard, M. Lengaigne, V. S. N. Murty, M. J. McPhaden, M.F. Cronin and F. Pinsard and K. Gopala Reddy, 2013: TropFlux wind stresses over the tropical oceans: evaluation and comparison with other products, Climate Dynamics, 40(7-8), 2049-2071, doi:10.1007/s00382-012-1455-4 |
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