The effects of convective and wind-driven mixing on springtime phytoplankton dynamics as simulated by a mixed-layer model

• Other Authors: Eslinger, David LeMar., Florida State University
• Format: Text
• Language: English
• Subjects: Biology; Oceanography; Bering Sea
• Online Access: http://purl.flvc.org/fsu/lib/digcoll/etd/3162197; http://fsu.digital.flvc.org/islandora/object/fsu%3A78395/datastream/TN/view/The%20effects%20of%20convective%20and%20wind-driven%20mixing%20on%20springtime%20phytoplankton%20dynamics%20as%20simulated%20by%20a%20mixed-layer%20model.jpg

A mixed-layer model of springtime phytoplankton dynamics was used to simulate spring phytoplankton blooms on the Bering Sea shelf, on the northern Mid-Atlantic Bight shelf, and over the entire Mid-Atlantic Bight. Convective mixing of the water column, caused by atmospheric cooling of the surface waters, was important in determining the timing of the spring phytoplankton bloom in all model domains. In the Bering Sea during 1980 and 1981, the spring bloom did not occur in the first period of low wind speed, but rather occurred in the first period of low wind speed following the cessation of convective mixing. However, interannual differences between the 1980 and 1981 phytoplankton blooms indicate that winds have significant effects on phytoplankton dynamics. Small differences in the magnitude and variability of wind speed can significantly affect the strength and character of the phytoplankton bloom. In the northern Mid-Atlantic Bight simulation, net phytoplankton growth occurred only in the absence of deep convective mixing. Upon the initiation of vernal atmospheric warming and the cessation of deep convective mixing, the major spring bloom occurred on the northern Mid-Atlantic Bight shelf in 1984. When run as an N $\times$ 1-D model over the entire Mid-Atlantic Bight, the model simulated the general features of the 1979 Mid-Atlantic Bight spring phytoplankton bloom seen in a series of CZCS images. In the Mid-Atlantic Bight model, convective mixing controlled the timing of the spring bloom and, through spatial variations in convective overturning of the water column, the spatial distribution of the bloom. Source: Dissertation Abstracts International, Volume: 51-12, Section: B, page: 5743. Major Professor: Richard L. Iverson. Thesis (Ph.D.)--The Florida State University, 1990.