jones123

Hi, my textbook has given the following weather sounding as a typical formation of a cumulonimbus (thunderstorm) cloud. But I don't really understand why this can happen on this figure. The LCL is situated left of the environmental temperature (red curve) so actually, the air parcel should stop rising in the middle between the LCL arrow and the Γ = Γd arrow (since it's in a stable layer) right? So i see this as a situation where no clouds can form. Can someone confirm this or explain why I'm wrong? Thanks!

No it isn't. We've breen through it in class today but I didn't really get it. We are supposed to see the flow direction by looking at smooth slopes on one side of the (inner/outer) curve and steep slopes on the other. But as I said, I don't understand that reasoning...

Hello, I do not really understand how one can determine the flow direction of a river by looking at a topographic map (see attachment). Does the river flow from north to south or from south to north? I think it has to do something with the steepness of the meanders on either side, but I do not really understand the full process. Can anyone help me figure it out? Thanks already!

Hi, I'm having troubles understanding the principles of dew point temperature. From wikipedia: "The dew point is the temperature below which the water vapor in a volume of humid air at a given constant pressure will condense into liquid water" "Relative humidity is the ratio of the partial pressure of water vapor in an air-water mixture to the saturated vapor pressure of water at a prescribed temperature" so RH = e/es. My question is: If air cools, it could hold less water vapor, so es will decrease (Clausius Clapeyron law) so that RH must increase. But how do I have to interpret dew point temperature? The definition says air must cool at a constant pressure (es). But I just mentioned that es must decrease when air cools so basically it can never be constant when air cools? It seems a bit confusing to me. I hope I made my problem clear and that someone can explain! Thanks!

Okay, thank you for making that clear to me. Actually, these aren't homework questions but these are problems that I encountered while reading through my lecture notes 1) What makes the difference if a soil will leach out completely or a soil where clay or other material illuviation will take place? I think this one has something to do with the nature of the sediments which build up the soil. Some minerals like calcite will easily solve when percolating water passes (soil particles will leach out completely), others are more weathering-resistant, leaving behind fine clay minerals which accumulate in the B-horizont but I'm not quite sure (= luvisols). 2) Why are podzolic soils acidic? Podzolisation is the process in which acidic organic matter-metal complexes are formed, which then move downward in the soil. I'm not sure if it is the presence of this organic matter that makes the soil acidic (I'd say that because they move downward the acidity will as well) or other processes? 3) Why is there an upward movement of groundwater in arid areas (what causes this)? I think this has to do something with capillary forces being larger than gravital forces. But I don't really know if this is the only aspect influencing this proces 4) Why is kaolinite often formed at the base of tropical soils? Probably due to high and intensive rainfall and percolation of dissolved soil particles, leaving clay minerals behind (ferralsols, ...), but then what's the difference with luvisols because clay accumulation is much deeper in tropical areas? I hope this wil prove you some evidence that I did try to answer these questions

1) What makes the difference if a soil will leach out completely or a soil where clay or other material illuviation will take place? 2) Why are podzolic soils acidic? 3) Why is there an upward movement of groundwater in arid areas (what causes this)? 4) Why is kaolinite often formed at the base of tropical soils? Thanks!

Hi, I was asked to evaluate the following article, concerning the disadvantages of biofuels: http://faculty.ucmerced.edu/ecampbell3/duane/Fargione-carbondebt-2008.pdf But there are some things about figure 1 that I do not completely understand: 1) In the text it says: "Converting lowland tropical rainforest in Indonesia and Malaysia to palm biodiesel would result in a biofuel carbon debt of ~610 Mg of CO2 ha−1 that would take ~86 years to repay (Fig. 1D)" while the figure shows 702? 2) Figure 1C and D: "Number of years after conversion to biofuel production required for cumulative biofuel GHG reductions, relative to the fossil fuels they displace, to repay the biofuel carbon debt" Does this mean while continuing biofuel (and so CO2) production (then there would be more CO2 released during these years which accumulates to the initial release...) or after it stopped 50 years earlier? And what does this 'relative to fossil fuels they displace' mean? Thanks a lot!