scholarly journals Ocean Surface Flux Algorithm Effects on Tropical Indo-Pacific Intraseasonal Precipitation

2021 ◽  
Author(s):  
Chia-Wei Hsu ◽  
Charlotte A. DeMott ◽  
Mark Branson ◽  
Jack Reeves Eyre ◽  
Xubin Zeng
Keyword(s):  
Surface Flux ◽  
Ocean Surface

scholarly journals An Assessment of the Uncertainties in Ocean Surface Turbulent Fluxes in 11 Reanalysis, Satellite-Derived, and Combined Global Datasets

2011 ◽  
Vol 24 (21) ◽  
pp. 5469-5493 ◽  
Author(s):  
Michael A. Brunke ◽  
Zhuo Wang ◽  
Xubin Zeng ◽  
Michael Bosilovich ◽  
Chung-Lin Shie
Keyword(s):  
Wind Stress ◽  
Coupled System ◽  
Surface Flux ◽  
Ocean Surface ◽  
Turbulent Fluxes ◽  
Department Of Energy ◽  
Strong Wind ◽  
Wind Speeds ◽  
Direct Covariance ◽  
Environmental Prediction

Abstract Ocean surface turbulent fluxes play an important role in the energy and water cycles of the atmosphere–ocean coupled system, and several flux products have become available in recent years. Here, turbulent fluxes from 6 widely used reanalyses, 4 satellite-derived flux products, and 2 combined product are evaluated by comparison with direct covariance latent heat (LH) and sensible heat (SH) fluxes and inertial-dissipation wind stresses measured from 12 cruises over the tropics and mid- and high latitudes. The biases range from −3.0 to 20.2 W m−2 for LH flux, from −1.4 to 6.0 W m−2 for SH flux, and from −7.6 to 7.9 × 10−3 N m−2 for wind stress. These biases are small for moderate wind speeds but diverge for strong wind speeds (>10 m s−1). The total flux biases are then further evaluated by dividing them into uncertainties due to errors in the bulk variables and the residual uncertainty. The bulk-variable-caused uncertainty dominates many products’ SH flux and wind stress biases. The biases in the bulk variables that contribute to this uncertainty can be quite high depending on the cruise and the variable. On the basis of a ranking of each product’s flux, it is found that the Modern-Era Retrospective Analysis for Research and Applications (MERRA) is among the “best performing” for all three fluxes. Also, the European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis (ERA-Interim) and the National Centers for Environmental Prediction–Department of Energy (NCEP–DOE) reanalysis are among the best performing for two of the three fluxes. Of the satellite-derived products, version 2b of the Goddard Satellite-Based Surface Turbulent Fluxes (GSSTF2b) is among the best performing for two of the three fluxes. Also among the best performing for only one of the fluxes are the 40-yr ERA (ERA-40) and the combined product objectively analyzed air–sea fluxes (OAFlux). Direction for the future development of ocean surface flux datasets is also suggested.

scholarly journals High-Resolution Satellite Surface Latent Heat Fluxes in North Atlantic Hurricanes

2011 ◽  
Vol 139 (9) ◽  
pp. 2735-2747 ◽  
Author(s):  
Jiping Liu ◽  
Judith A. Curry ◽  
Carol Anne Clayson ◽  
Mark A. Bourassa
Keyword(s):  
High Resolution ◽  
Latent Heat ◽  
North Atlantic ◽  
Weather Prediction ◽  
Surface Flux ◽  
Ocean Surface ◽  
Ocean Waves ◽  
Heat Fluxes ◽  
Atlantic Hurricanes ◽  
Better Than

This study presents a new high-resolution satellite-derived ocean surface flux product, XSeaFlux, which is evaluated for its potential use in hurricane studies. The XSeaFlux employs new satellite datasets using improved retrieval methods, and uses a new bulk flux algorithm formulated for high wind conditions. The XSeaFlux latent heat flux (LHF) performs much better than the existing numerical weather prediction reanalysis and satellite-derived flux products in a comparison with measurements from the Coupled Boundary Layer Air–Sea Transfer (CBLAST) field experiment. Also, the XSeaFlux shows well-organized LHF structure and large LHF values in response to hurricane conditions relative to the other flux products. The XSeaFlux dataset is used to interpret details of the ocean surface LHF for selected North Atlantic hurricanes. Analysis of the XSeaFlux dataset suggests that ocean waves, sea spray, and cold wake have substantial impacts on LHF associated with the hurricanes.

On the possibility of remotely sensing global dimethyl sulfide sea-to-air flux

Polar Record ◽  
1995 ◽  
Vol 31 (177) ◽  
pp. 251-256 ◽  
Author(s):  
Clara M. Jodwalis ◽  
Richard L. Benner
Keyword(s):  
Dimethyl Sulfide ◽  
Surface Flux ◽  
Ocean Surface ◽  
Global Scale ◽  
The Arctic ◽  
Remotely Sensed Data ◽  
Gas Flux ◽  
Measuring Surface ◽  
A New Technique ◽  
Chemiluminescence Detector

AbstractBiogenic emissions of sulfur from the ocean surface are believed to be a significant contribution to the atmospheric aerosol burden, thus playing a significant role in climate. The possibility exists for using remotely sensed data to locate sources, map distributions, and estimate global-scale fluxes of marine sulfur flux. By definition, estimates of surface trace-gas flux from satellites are indirect. Empirical algorithms must be derived using direct surface flux measurements. This technology does not currently exist, and may be many years from coming to fruition. This paper discusses the possibilities of developing a satellite-based dimethyl sulphide (DMS) flux capability and describes a new technique that can be used to develop the necessary empirical relationships. It demonstrates the feasibility of using a sulfur chemiluminescence detector (SCD) for measuring surface sulfur-gas flux directly from the ground. It also estimates ocean surface sulfur-gas flux using two related, indirect methods, known as the variance method and the inertial dissipation method. These methods can be used in the Arctic, where the ocean-to-atmosphere flux may be a significant fraction of global biogenic sulfur emissions.

scholarly journals The Naval Research Laboratory Ocean Surface Flux (NFLUX) System: Satellite-Based Turbulent Heat Flux Products

2016 ◽  
Vol 55 (5) ◽  
pp. 1221-1237 ◽  
Author(s):  
Jackie C. May ◽  
Clark Rowley ◽  
Neil Van de Voorde
Keyword(s):  
Heat Flux ◽  
Satellite Data ◽  
Surface State ◽  
Research Laboratory ◽  
State Parameter ◽  
Surface Flux ◽  
Ocean Surface ◽  
Turbulent Heat Flux ◽  
Naval Research ◽  
Turbulent Heat

AbstractThe Naval Research Laboratory ocean surface flux (NFLUX) system provides satellite-based surface state parameter and surface turbulent heat flux fields operationally over the global ocean. These products are presented as an alternative to using numerical weather prediction models—namely, the U.S. Navy Global Environmental Model (NAVGEM)—to provide the surface forcing to operational ocean models. NFLUX utilizes satellite sensor data records from the Special Sensor Microwave Imager/Sounder (SSMIS), the Advanced Microwave Sounding Unit-A (AMSU-A), the Advanced Technology Microwave Sounder (ATMS), and the Advanced Microwave Scanning Radiometer-2 (AMSR-2) sensors as well as satellite environmental data records from WindSat, the Advanced Scatterometers (ASCAT), and the Oceansat scatterometer (OSCAT). The satellite data are processed and translated into estimates of surface specific humidity, surface air temperature, and 10-m scalar wind speed. Two-dimensional variational analyses of quality-controlled satellite data, in combination with an atmospheric-model field, form global gridded surface state parameter fields. Bulk formulas are then applied to produce surface turbulent heat flux fields. Six-hourly analysis fields are created from 1 January 2013 through 31 December 2013. These fields are examined and validated against in situ data and NAVGEM. Overall, the NFLUX fields have a smaller bias, lower or similar root-mean-square error, and increased skill score relative to those of NAVGEM.

Surface Flux Observations on the Southeastern Tropical Pacific Ocean and Attribution of SST Errors in Coupled Ocean–Atmosphere Models

2010 ◽  
Vol 23 (15) ◽  
pp. 4152-4174 ◽  
Author(s):  
Simon P. de Szoeke ◽  
Christopher W. Fairall ◽  
Daniel E. Wolfe ◽  
Ludovic Bariteau ◽  
Paquita Zuidema
Keyword(s):  
Heat Flux ◽  
Pacific Ocean ◽  
Radiative Forcing ◽  
General Circulation ◽  
Surface Flux ◽  
Ocean Surface ◽  
Tropical Pacific ◽  
Turbulent Heat ◽  
Tropical Pacific Ocean ◽  
Coupled Models

Abstract A new dataset synthesizes in situ and remote sensing observations from research ships deployed to the southeastern tropical Pacific stratocumulus region for 7 years in boreal fall. Surface meteorology, turbulent and radiative fluxes, aerosols, cloud properties, and rawinsonde profiles were measured on nine ship transects along 20°S from 75° to 85°W. Fluxes at the ocean surface are essential to the equilibrium SST. Solar radiation is the only warming net heat flux, with 180–200 W m−2 in boreal fall. The strongest cooling is evaporation (60–100 W m−2), followed by net thermal infrared radiation (30 W m−2) and sensible heat flux (<10 W m−2). The 70 W m−2 imbalance of heating at the surface reflects the seasonal SST tendency and some 30 W m−2 cooling that is mostly due to ocean transport. Coupled models simulate significant SST errors in the eastern tropical Pacific Ocean. Three different observation-based gridded ocean surface flux products agree with ship and buoy observations, while fluxes simulated by 15 Coupled Model Intercomparison Project phase 3 [CMIP3; used for the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report] general circulation models have relatively large errors. This suggests the gridded observation-based flux datasets are sufficiently accurate for verifying coupled models. Longwave cooling and solar warming are correlated among model simulations, consistent with cloud radiative forcing and low cloud amount differences. In those simulations with excessive solar heating, elevated SST also results in larger evaporation and longwave cooling to compensate for the solar excess. Excessive turbulent heat fluxes (10–90 W m−2 cooling, mostly evaporation) are the largest errors in simulations once the compensation between solar and longwave radiation is taken into account. In addition to excessive solar warming and evaporation, models simulate too little oceanic residual cooling in the southeastern tropical Pacific Ocean.

scholarly journals Ocean Surface Flux Algorithm Effects on Earth System Model Energy and Water Cycles

2021 ◽  
Vol 8 ◽  
Author(s):  
J. E. Jack Reeves Eyre ◽  
Xubin Zeng ◽  
Kai Zhang
Keyword(s):  
Surface Flux ◽  
Ocean Surface ◽  
Earth System Model ◽  
Surface Fluxes ◽  
System Model ◽  
Earth System ◽  
Ocean Heat Uptake ◽  
Wind Speeds ◽  
Global Mean ◽  
Water Cycles

Earth system models parameterize ocean surface fluxes of heat, moisture, and momentum with empirical bulk flux algorithms, which introduce biases and uncertainties into simulations. We investigate the atmosphere and ocean model sensitivity to algorithm choice in the Energy Exascale Earth System Model (E3SM). Flux differences between algorithms are larger in atmosphere simulations (where wind speeds can vary) than ocean simulations (where wind speeds are fixed by forcing data). Surface flux changes lead to global scale changes in the energy and water cycles, notably including ocean heat uptake and global mean precipitation rates. Compared to the control algorithm, both COARE and University of Arizona (UA) algorithms reduce global mean precipitation and top of atmosphere radiative biases. Further, UA may slightly reduce biases in ocean meridional heat transport. We speculate that changes seen here, especially in the ocean, could be even larger in coupled simulations.

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