An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea.

Estuaries form a transition zone between river environments and ocean environments and are subject to both marine influences, such as tides, waves, and the influx of saline water; and riverine influences, such as flows of fresh water and sediment. The inflow of both seawater and freshwater provide high levels of nutrients in both the water column and sediment, making estuaries among the most productive natural habitats in the world.

Most modern-day estuaries were formed during the Holocene epoch by the flooding of river-eroded or glacially-scoured valleys when sea level began to rise about 10,000-12,000 years ago. Estuaries are typically classified by their geomorphological features or by water circulation patterns and can be referred to by many different names, such as bays, harbors, lagoons, inlets, or sounds, although sometimes these water bodies do not necessarily meet the above criteria of an estuary and may be fully saline.

Tom Harrell (born June 16, 1946) is a renowned American post-bop jazz trumpeter, flugelhornist, composer and arranger.

Harrell has won numerous awards and grants, including multiple Trumpeter of the Year awards from Down Beat magazine,SESAC Jazz Award, BMI (Broadcast Music Incorporated) Composers Award, and Prix Oscar du Jazz. He also received a Grammy nomination for his big band album, Time's Mirror.

He has been recorded on over 260 albums (according to the discography on his website) and continues to actively compose, record and tour extensively around the world.

Tom Harrell was born in Urbana, Illinois, but moved to the San Francisco Bay Area at the age of five. He started playing trumpet at eight and within five years, started playing gigs with local bands. In 1969 he graduated from Stanford University with a music composition degree and joined Stan Kenton's orchestra, touring and recording with them throughout 1969.

After leaving Kenton, Harrell played with Woody Herman's big band (1970–1971), Azteca (1972), the Horace Silver Quintet (1973–1977), with whom he made five albums, the Sam Jones-Tom Harrell Big Band, the Lee Konitz Nonet (1979–1981), George Russell, and the Mel Lewis Orchestra (1981). From 1983 to 1989 he was a pivotal member of the Phil Woods Quintet and made seven albums with the group. In addition, he recorded albums with Vince Guaraldi for whom he also did some arranging for the Peanuts television specials, Bill Evans, Dizzy Gillespie, Ronnie Cuber, Bob Brookmeyer, Lionel Hampton, Bob Berg, Cecil Payne, Bobby Shew, Phillipe Catherine, Ivan Paduart, Joe Lovano, Charlie Haden's Liberation Orchestra, Art Farmer, Charles McPherson, David Sánchez, Sheila Jordan, Jane Monheit, King's Singers and Kathleen Battle among others.