Variation and uncertainty in evaporation from a subtropical estuary: Florida Bay

Abstract

Variation and uncertainty in estimated evaporation was determined over time and between two locations in Florida Bay, a subtropical estuary. Meteorological data was collected from September 2001 to August 2002 at Rabbit Key and Butternut Key within the bay.Evaporation was estimated using both vapor-flux and energy-budget based methods. The results were then placed into a long-term temporal context using 33 years of temperature and rainfall data collected in south Florida. Evaporation also was estimated from this long-term data using an empirical formula relating evaporation to clear sky solar radiation and air temperature.Evaporation estimates for the 12 month period ranged from 144 to 175 cm yr -1 , depending on location and method, with an average of 163 cm yr -1 ("9%). Monthly values ranged from 9.2 cm to 18.5 cm, with the highest value observed in May, corresponding with the maximum in measured net radiation. Uncertainty estimates derived from measurement errors in the data were as much as 10%, and were large enough to obscure differences in evaporation between the two sites. Differences among all estimates for any month indicate the overall uncertainty in monthly evaporation, and ranged from 9% to 26%. Over a 33-year period (1970 -2002), estimated annual evaporation from Florida Bay ranged from 148 to 181 cm yr -1 , with an average of 166 cm yr -1 . Rainfall was consistently lower in Florida Bay than evaporation, with a long-term average of 106 cm yr -1 Rainfall considered alone was uncorrelated with evaporation at both monthly and annual time scales; however, when the seasonal variation in clear sky radiation also was taken into account both net radiation and evaporation were significantly suppressed in months with high rainfall.

Assessment of uncertainty in estimating the evaporation from the Curonian Lagoon

“…Winter (1981) indicated that errors in estimates of evaporation could vary widely depending on instrumentation and methodology; according to this scientist, the energy budget is the most accurate method (errors are in 10-15 percent range). Price et al (2007) investigated variation and uncertainty in evaporation from subtropical estuary and found out that the uncertainty estimates derived from measurement errors in the data were 10 percent. In the water balance study of the Great Lakes immense hydrologic system, evaporation uncertainty was assumed to range between 10 and 35 percent (Neff, Nicholas 2005).…”

Long-term (11 years) study of water balance, flushing times and water chemistry of a coastal wetland undergoing restoration, Everglades, Florida, USA

“…In ArcGIS, the station data was used to create Thiessen Polygon layers to obtain spatial precipitation values for each month. Precipitation data used in the water budget were assumed to have a 10% error (Price et al, 2007). Monthly and annual precipitation totals calculated for southern Taylor Slough between 2001 and 2011 were compared to 40-year (1970-2010) average values for the Royal Palm Ranger Station (RPL; Fig.…”

Preliminary Hybrid Modeling of the Panama Canal: Operations and Salinity Diffusion

“…EX L3 and EX L4 are the exchange ratios for Locks L3 and L4, respectively. Piecewise linear profiles of Evaporation (Evaporation (t)) and precipitation (Precipitation (t)) are added to the calculations of V GL [13][14][15][16][17]. The different equations were implemented in AnyLogic [7,[18][19][20].…”