Premium
River runoff effect on the suspended sediment property in the upper C hesapeake B ay using MODIS observations and ROMS simulations
Author(s) -
Liu Xiaoming,
Wang Menghua
Publication year - 2014
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2014jc010081
Subject(s) - bay , environmental science , estuary , moderate resolution imaging spectroradiometer , discharge , surface runoff , sediment , chesapeake bay , total suspended solids , hydrology (agriculture) , storm , satellite , oceanography , geology , drainage basin , geography , chemical oxygen demand , wastewater , ecology , cartography , geotechnical engineering , engineering , biology , aerospace engineering , paleontology , environmental engineering
Abstract Ocean color data derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the satellite Aqua from 2002 to 2012 and simulations from the Regional Ocean Modeling System (ROMS) are used to study the impact of the Susquehanna River discharge on the total suspended sediment (TSS) concentration in the upper Chesapeake Bay. Since the water in the upper Chesapeake Bay is highly turbid, the shortwave infrared (SWIR)‐based atmospheric correction algorithm is used for deriving the normalized water‐leaving radiance nL w ( λ ) spectra from MODIS‐Aqua measurements. nL w ( λ ) spectra are further processed into the diffuse attenuation coefficient at the wavelength of 490 nm K d (490) and TSS. MODIS‐Aqua‐derived monthly TSS concentration in the upper Chesapeake Bay and in situ Susquehanna River discharge data show similar patterns in seasonal variations. The TSS monthly temporal variation in the upper Chesapeake Bay is also found in phase with the monthly averaged river discharge data. Since the Susquehanna River discharge is mainly dominated by a few high discharge events due to winter‐spring freshets or tropical storms in each year, the impact of these high discharge events on the upper Chesapeake Bay TSS is investigated. Both MODIS‐measured daily TSS images and sediment data derived from ROMS simulations show that the Susquehanna River discharge is the dominant factor for the variations of TSS concentration in the upper Chesapeake Bay. Although the high river discharge event usually lasts for only a few days, its induced high TSS concentration in the upper Chesapeake Bay can sustain for ∼10–20 days. The elongated TSS rebounding stage is attributed to horizontal advection of slowly settling fine sediment from the Susquehanna River.