Low Inflow Estuaries (LIEs) Hypersaline, Inverse & Thermal Estuaries Stommel Transitions

Low Inflow Estuaries (LIEs) Hypersaline, Inverse & Thermal Estuaries Stommel Transitions

Largier’s Notes

Depends on the Density gradient (Hearn and Sidhu, 2003) How and when does the system reverse? Hypersaline but not Inverse

Heating Precipitation Freshwater Se, Te Flux out Q So, To Flux in Cooling Evaporation Freshwater So, To Flux in Se, Te Q Flux out INVERSE Salt and Heat Conservation CLASSICAL Relative influence of temperature and salinity on density gradients

Largier’s Notes Hyposaline but not classical…

IN Guaymas Bay OUT Inverse Estuary OUT OUT IN Classical Estuary Valle-Levinson et al., 2001

Wet Period: Classical Dry period: Inverse Neap Tides Distance from Transect Origin (km) Mean Flow – Transect 4 Interface slope, spring tides ~ 2.5e-03 (25 m in 10 km) Interface slope, neap tides ~ 2.0e-03 (18 m in 9 km) IN OUT IN OUT Importance: Water and Soil Quality (?) Climate Variability Valle-Levinson and Bosley, 2003

Largier’s Notes Stommel Transitions

Can we detect Stommel Transitions in Florida’s lagoons and estuaries? What is the temporal scale of these transitions? What happens to the sites adjacent to the lagoons (agriculture, tourism)? Do they become more vulnerable to droughts? Implications for water and soil quality

Pine Island San Sebastian Ft.Matanzas

Global Conveyor Belt (From Broecker,1990; in Pinet, 1998)

From conservation of salt and heat, the difference between oceanic and estuarine salinity is defined as S and given by: The difference between oceanic and estuarine temperature is defined as T and given by: and the difference between oceanic and estuarine density is defined as Δρand given by: So the relative influence of T and S can be calculated as: but: Relative influence of temperature and salinity on density gradients Whitehead (1998, Estuaries, 21(2), 281) O refers to oceanic and R to river; Qis volume influx from ocean to estuary; tS is the basin Volume V divided by River Discharge; tT is 15 times smaller than tS

In reality: Relative influence of temperature and salinity on density gradients Salinity Influence Net influence Temperature Influence V = 109 m3 q = 100 m3/s SO – SR = 15 TO – TR = 25 Q

For multiple states, a) Q = 0 when ; and b) the line intersects the density curve at 3 points Multiple states --- Stommel Transitions S mode Salinity Influence Net Influence Temperature Influence T mode Q

Salinity-dominated response Temperature-dominated response

Critical Response for Development of Multiple States Salinity Influence Net Influence Temperature Influence Q

(Proxy for Evaporation) (Hearn and Sidhu, 2003)

(Hearn and Sidhu, 2003)

L = 15 km L = 0.85*15 km (Evaporation) (Hearn and Sidhu, 2003)

The truncation of the lagoon may impede a transition to INVERSE ESTUARY (Hearn and Sidhu, 2003)

Low Inflow Estuaries (LIEs) Hypersaline, Inverse & Thermal Estuaries Stommel Transitions