Marine Chemistry and Biological Oceanography 海洋化學與生物海洋.
-
date post
20-Dec-2015 -
Category
Documents
-
view
299 -
download
5
Transcript of Marine Chemistry and Biological Oceanography 海洋化學與生物海洋.
Marine Chemistry and Biological Oceanography
海洋化學與生物海洋
Biology starts with chemistry
• Biological processes – the levels of elements and compounds
• Abundance of biota and tropic relationship – chemical parameters, salinity, dissolved oxygen and nutrient
Global water cycle
turnover time
• The ocean has a turnover time of about 37,000 years with respect to river inflow. This is how long it would take to fill the ocean if it were totally dry.
• Turnover times are defined as the mass in the reservoir divided by the input or removal rate. By comparison the average residence time of water in the atmosphere with respect to evaporation from the oceans and continents is only about 10 days.
Scope of Chemical Oceanography: Fundamental Questions
• - What are the chemical controls on biological production and food web structure of the ocean? In some ocean areas iron limits phytoplankton growth.
• Martin (1991) conducted experiments where he added iron to samples and showed that adding iron stimulated growth rate and also stimulated diatom production.
• Martin (1991) conducted experiments where he added iron to samples and showed that adding iron stimulated growth rate and also stimulated diatom production.
- In what ways do biological processes control the distributions of chemicals in the ocean?
• Photosynthesis and respiration control the distribution of many elements in seawater.
Compositions of sea water
• 0.45 m filter
• Passed –
• Can not pass –
• Humic acid, protein and amino acid, polysaccharide, pigments, inorganic colloids (iron hydroxide)
salinity
• Total amount of salts in water
Bioavailability
• Can be utilized by cells - membrane• related to dissolved materials and particulate ma
terials
• Most particulate materials can not be efficiently utilized by phytoplankton and algae
• 理由 : large size of particulate materials – can not pass through cell membrane or via the channel
Speciation and global hydrological cycle
7 days
3550 days
Global hydrological cycle
Time-dependent events
Dissolved gases
• Oxygen: dissolved oxygen (DO)
• Surface, temperature, biological utilization and emission
• 2.0-10 mg/L intertidal regions
• Vertical distribution: 50 m no variation
• Photosynthesis (+O2)
• Respiration (-O2)
Primary productivity
CO2 cycle
• CO2 (gas) ↔ CO2 (dissolved)• H2O + CO2 ↔ H2CO3
• H2CO3 ↔ H+ + HCO3-
• HCO3- ↔ H+ + CO3
2-
• Ca2+ + CO32- ↔ CaCO3 (solid)
• 表示法 : alkalinity (A) – the number of moles of hydrogen ion required to convert all anions of weak acids to their unionized form in 1 kg of water
pH and CO2
CO2 cycle
C cycle
Nutrient
• Phosphorus (P)• Nitrogen (N)• Co-variation of N and P• Refield atomic ratio: C:N:P=106:16:1 (1934, 1
963)• N:P ratio > 30:1 P limitation• N:P ratio < 10:1 N limitation
• Silicon
Spatial variations
Temporal variations
Organic carbon
• Dissolved organic carbon DOC
• Particular organic carbon POC• POC in photic zone is recycled by micro-organisms.