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Title page. Physiological Considerations of Phytoplankton in the Context of GEOCAPE Capabilities Tiffany H.A. Moisan (NASA/GSFC), John R. Moisan (NASA/GSFC), and Rachel Steinhardt (Sigma Space). “ Possible Geocape Capabilities Measurements of Diurnal Variability with
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Title page Physiological Considerations of Phytoplankton in the Context of GEOCAPE Capabilities Tiffany H.A. Moisan (NASA/GSFC), John R. Moisan (NASA/GSFC), and Rachel Steinhardt (Sigma Space)
“ Possible Geocape Capabilities Measurements of Diurnal Variability with Requirements of hours to days……………. “
Diel Periodicity of Photosynthesis Variability Prezelin 1972
Objectives • Demonstrate experimental results of Diurnally bio-optical characteristics, • Show cloud cover probability maps of different light intensities (PAR) in the GEOCAPE target area, • Pigment ratios which are affected by nutrients (e.g. eutrophication/pollution) can affect chlorophyll a fluorescence, • Demonstrate how chlorophyll a and FLH correlates in the GEOCAP target area (example: harmful algal bloom).
Chesapeake Light Tower ** Diurnal Cycle for One Year at the mouth of the Chesapeake Bay
LEO Probability of one clear pixel on a given day The probability of obtaining a complete time series over one single day of observing with a GEO satellite is about what is Is for obtaining a pixel on a given day for a LEO satellite. John R. Moisan GEO Probability of at least on clear pixel per day
Leo and Geo Derived PAR Products John R. Moisan
Time Series along the COBY Transect In the Mid Atlantic Bight (Moisan et al. 2010)
Diurnal Experiments of Phytoplankton Physiology • Conducted Diurnal Experiments • Incubations begin at ~6 a.m. and sample for • 12 hours every two hours • Every hour around noon • Measurements include • Fluorescence • Variable fluorescence • Estimate non-photochem. • quenching • Chl-specific absorption • HPLC pigments • Temperature • Light • Cell counts • Taxonomic composition • POC/PON
Xanthophyll Cycling of Diatoxanthin and Diadinoxanthin: Changes in Chlorophyll a Fluorescence
Diel Periodicity varies with Different PFTs
MODIS/Aqua images on 21 January 2005 Most of the band-ratio “Chl” is a false interpretation of CDOM and suspended sediments, but FLH is a more accurate indicator of biomass. In this case, the high FLH patch off Tampa Bay is a confirmed Karenia brevis bloom. (a) ERGB (b) Chl (c) FLH A B Courtesy of Dr, Chuanmin Hu
Questions and Conclusions • The temporal resolution of Geocape will support new physiological • observations on unprecedented spatial scales • “linking short-time processes to remotely- sensed scales such • as mixing, productivity (biophysical constraints), uptake etc.” • Defining diurnal responses with Geocape requirements will • be a next challenge in understanding probabilities of cloud-free • skies • The temporal resolution will most likely lead to a more detailed • development of satellite products as we merge spatial and temporal • scales.
Observations of Diurnal Variability will increase the accuracy of estimates of Phytoplankton Physiology • Including relative more low light observations will increase carbon estimates significantly; • Inclusion of a diurnal signal will increase the accuracy of primary productivity, possible drawdown of pollution, and give status estimates of health (photoinhibition and pollution by eutrophication); and, • Diurnal signals of productivity can vary seasonally with temperature, nutrients (eutrophication) and light (PAR, spectrally).