Fluxes With input from: USCLIVAR Working Group on High-Latitude Fluxes: Ed Andreas, Cecelia Bitz, Dave Carlson, Ivana Cerovecki, Meghan Cronin, , Will Drennan , ( - ) Chris Fairall Sarah Gille co chair , , , Ross Hoffman Gudrun Magnusdotti Rachel Pinker, Ian Renfrew, Mark Serreze, Kevin Speer, Lynne Talley, Gary Wick Fluxes from Space: Carol Anne Clayson, Sarah Gille, Darren Jackson, Brent Roberts, Joel Scott, Shawn Smith, Gary Wick Ocean Modeling and Reanalysis Comparison: Dmitry Dukhovskoy and Paul Hughes Mark A. Bourassa COAPS & EOAS, Florida State University, [email protected]
Transcript
Fluxes
With input from:USCLIVAR Working Group on High-Latitude Fluxes: Ed Andreas, Cecelia Bitz, Dave
Carlson, Ivana Cerovecki, Meghan Cronin, Will Drennan, Chris Fairall, Sarah Gille (co-chair), Ross Hoffman, Gudrun Magnusdotti, Rachel Pinker, Ian Renfrew, Mark Serreze, Kevin Speer, Lynne Talley, Gary Wick
Fluxes from Space: Carol Anne Clayson, Sarah Gille, Darren Jackson, Brent Roberts, Joel Scott, Shawn Smith, Gary Wick
Ocean Modeling and Reanalysis Comparison: Dmitry Dukhovskoy and Paul Hughes
Mark A. BourassaCOAPS & EOAS, Florida State University, [email protected]
Distribution of SHF is Inconsistent Among Products
Selected Motivations Differences between flux products are much too large
Differences are reduced in modern products (Bourassa et al.) It has been suggested that surface fluxes play a large role in several
aspects of Arctic ice melt and growthLinks to oceanic deep convection
Deep water formation in the Southern Ocean might be influenced by fluxes – particularly latent heat flux (Speer)
Indian ocean dynamics very sensitive to surface fluxes Large latent heat flux over water contributes to both the energy and
water cycles Observed changes in Hadley and Walker circulation should be
associated with changes in surface fluxes SST gradients near western boundary currents estimated to cause
monthly averaged regional changes in latent heat flux of >30Wm-2
Surface moisture convergence linked to some clouds?
Accuracy Requirements Fluxes are estimated through bulk formulas Goal <5Wm-2 bias in sum of latent and sensible heat flux
Goal assessments were done by Chris FairallWind spd: 0.4 m/s threshold; 0.2 m/s goal; 0.1 m/s outstandingSST: 0.2 C threshold; 0.1 C goal; ? outstandingAir Temp: 0.2 C threshold; 0.1 C goal; ? OutstandingSpec humidity: 0.6 g/kg threshold; 0.3 g/kg goal; ? Outstanding
Goals on random error are not clear, as they are more relevant to short-lived and smaller area forcingFor the larger scale applications, sampling will overcome
random error. Both of the above statements assume that there is no cross
correlation of errors between variables.
Comparison of Two Retrieval Techniques
Blue – Roberts et al. (SeaFlux)
Red – Jackson and Wick
Need more data to improve extremes
Discussion
The period for comparison (for which all products are available) is 03/1992 through 12/2000.
Black line is the track from Ryan Maue’s data set Lack of retrieval in areas with too much rain
Input to Bulk Fluxes
USCLIVAR/SeaFlux 8
CCMP
NCEPRCFSR
0.004
0.03
0.05
0.08
0.1
0.12
0.15
Gree
nlan
dGr
eenl
and
Gree
nlan
d
ASR
Exceedance Probability (U>17 m/s) , winter 2005-2007
Evaluation of Satellite Retrievals of 10m Ta and Qa
Comparison to research vessel observations from SAMOS
