(1) Please define GPP. NPP, NEP respectively. (9 pt)

(2) Scientists use eddy-covariance tower to measure Net Ecosystem Exchange (NEE), which is a measure of CO2 fuxes between the ecosystem and its surro ounding environments. Does NEE equal to GPP or NPP or NEP? Why? (6 pt)

(3) View the latitudinal distribution of the global NPP below. A is global average, B is land average, and C is ocean average. Different lines indicate different seasons as explained in the figure captions. Please describe the latitudinal distribution patterns for NPP for land (5 pt) and ocean (5 pt) respectively. You may have noticed that for both land and ocean NPP. there is a local minimum around 20-30 degree N/S. Do they have similar or different reasons? Please explain. (10 pt)

(4) Now compare the latitudinal patterns of carbon storage on land in the following figure. The areas above 0 on the y axis is carbon storage above ground, and the areas below 0 on the y axis is carbon storage below ground (or soil organic carbon SOC for diflerent depths shown in the figure caption). Summarize the similarity and differences between the two (5 pt), explain what proce cesses drive the similarities and differences (5 pt). How would we predict future changes in carbon storage under the direct influence of CO2 rise and global warming (5 pt)?The latitudinal patterns of terrestrial carbon stocks, both aboveground living plant biomass (green) [data from Gibbs et al. (114)] and soil carbon stocks (brown) [data from Hengl et al. (18)].

(a) (6 pts) Above the ground and near the surface layer, aerobic(有 氧) respiration is a major process. Please write the overall reaction for aerobic respiration and calculate AE°(w) (using CH2Oas the reactant).

(b)(10 pts) Below the surface (anoxic(缺氧)conditions), other respiration processes, such as denitrification, sulfate reduction, and methanogenesis, might become significant. Please write the overall reaction for denitrification and sulfate reduction, and calculate AE°(w), respectively.

(c) (12 pts) Given your listed rcactions above (in a&b), please estimate their Gibbs free energy yield per clectron (in the unit of kcal per electron), using △G0 = - zF△E°(w) (z is the number of electrons, F is Faraday's constant 23.06 1 kcal/volt). Compare their Gibbs free energy, and explain how this would control the oxidation/reduction sequence in the sediments with the observed profile shown in Figure A. 

(d)Nitrification is the biological oxidation of ammonium to nitrite, followed by the oxidation of nitrite to nitrate under aerobic conditions.  (i) (4 pts) Please write the nitrification net reaction with a reactant of amnonium and the final product as nitrate.  (ii) (8 pts) If global net primary productivity on land is g C/yr, and the average C/N ratio of plant biomass is 100, what is the upper limit (i.e., maximum estimate) of oxygen used every year in microbial nitrification?

a) (8pts) The ozone formation ion over the stratosphere is based on the Chapman mechanism. Please describe the four major reactions of the Chapman mechanism.

b) (16 pts) The predicted [O3] profile based on steady-state assumption overestimates theO3 concentrations by a factor of 2 or more as shown in Figure 1-1 due to the missing sinks for O3, i.e., HOx, NOx and ClOx with the following propagation reactions: X is a catalyst such as OH, NO, and Cl Please describe what the initial chemical con mponents associated with HOx, NOx, and ClOx, and where they come from, and how the initial HOx, NOx, and ClOx are formed (the initiation step for radical formation).(明確描述在平流層産生HOx,NOxand CIOX的最原始物質及其來源為何,這些原始物質如何進到或出現在平流層,如何初步產生 HOx, NOx, and ClOx).

c) (12 pts) In the troposphere, ozone can be transported from stratosphere but is mainly produced by chemical reactions. Figure 1-2 shows the cyeling of HOx and O3; production in a polluted atmosphere. Please describe in detail how the ozone is formed in the troposphere (you can use CO or CH4 as an example to illustrate the processes).

110年 - 110 國立臺灣大學_碩士班招生考試_大氣科學研究所甲組:生地化循環與氣候#100478