**APPENDIX III. COMPARISON OF
FORMULAE AND DATA SOURCES USED ON THE HEAT FLUXES ESTIMATION IN THE GULF OF
MEXICO BY VARIOUS AUTHORS**

*1. Q _{c} computations*

For the computation of

Qusually the radiation in clear sky is computed first and with this data the net short-wave radiation is computed including the effect of clouds. The clear sky short-wave radiation_{s}(Qhas been computed by several authors:_{c})Hastenrath (1968) and Hastenrath and Lamb (1978) takes data from Bernhard and Phillips (1958) maps.

Etter (1983) and Etter

et al.(1987) used a combination of results from Bunker (1976) and Hastenrath and Lamb (1978).Bunker (1976) based its computations on Budyko (1963).

Adem

et al.(1993) used data from Budyko (1974).This work uses Seckel and Beaudry formula:

Q_{c}= A_{0}+ A_{1}cosɸ + B_{1}sinɸ + Acos_{2}2ɸ + Bsin_{2}2ɸ,from Reed (1977) and Reed (1983) for the coefficients values.

*2. Q _{s} estimations*

Hastenrath (1968) takes data from Bernhard and Phillips maps (1958). He used

A =6%.Etter (1983), and Etter

et al.(1987) used a combination of results from Bunker (1976) computed with the formula of Budyko and Hastenrath and Lamb (1978) data.Adem

et al.(1993) used the formula given by Budyko (1974),(_{1}I =Q + q)_{0}(1-(a + bC)C)(1-A),where (Q+ q)_{0}is the total radiation received by the surface with clear sky witha =0.35,b =0.38, (parameters recommended for 25°N),Cis the cloud cover in tenths, andA =6% the albedo at the sea surface.In this work we follow Reed (1977) using the formula

Q(1 - 0.62_{s}= Q_{c}C+ 0.0019)(1-A).

*3. Q _{b} computations*

Hastenrath (1968) used

Q_{b}= Q_{b0}_{}(1—0.60C), whereQ_{b0}_{}is the long-wave radiation for clear skies, andCthe fraction of sky covered by clouds (in tenths). He follow Kuhn (1962) for the computation ofQ_{b0}_{}.Etter (1983) and Etter

et al.(1987) used Hastenrath and Lamb (1978) results.Adem

et al.(1993) usedQ=_{b}-δσT[0.254 - 0.0066Ue_{a}^{4}_{s}(T)](1 -_{a}AC) -4δσT(_{a}^{3}T - T_{a}_{});from Budyko (1974), whereδ =0.96 is the emissivity of the sea surface,Ais the cloud cover coefficient (= 0.65 in their computation),Uis the relative humidity andethe saturation vapor pressure._{s}In this work we use

Q=_{b}σ∈T(0.254 - 0.00495e_{a}^{4}_{a})(1- 0.7C) following Reed (1983).

*9.4.* *Q _{e},
Q_{h}, C_{E}*

All works use the formulae:

Q_{e}= ρ(_{a}C_{E}wLq_{s}— q_{a}_{}) andQ_{h}= p(_{a}C_{p}C_{H}wT_{s}— T_{a}_{}),or an equivalent set using different unit system, but with different turbulent coefficients.Hastenrath (1968) used

C1.4 x 10_{E}= C_{H}=^{–3}.Etter (1983) and Etter

et al.(1987) computedQas an average of the results of the work of Budyko (1974), which uses_{e}C_{E}= C2.1 x 10_{H}=^{–3}, and Bunker (1976) with turbulent coefficients computed as a function of the wind speed and the difference of temperature between the air and the sea surface(Cand_{E}Cget values from 0.071 x 10_{H}^{–3}to 2.52 x 10^{–3}).Adem

et al.(1993, 1994) used an equivalent formula, withC_{E}=C= 1.6 x 10_{H}^{–3}.In this work

C_{E}=C= 1.4 x 10_{H}^{–3}, a value slightly higher than those suggested in recent papers (Geernaert, 1990).