Pauline, I don't see how you can retrieve LWP without anyhow involving a LWC profile. This for the simple reason that arts does not take LWP as input, but a LWC profile. So you must assume some default LWC profile, that I guess you scale.
> But I have a high convergence problem in Qpack when I retrieve the > liquid water content but I had to do some modifications in the oem.m > routine due to different units in my background error covariance > matrix and my jacobians. The problem is that the conversion from > kg/kg to g/m³ depends on pressure, temperature and the liquid water > content whereas the B matrix was computed from an ensemble > assimilation system with several members during a large period of > time with different LWC profiles.. I do not think I can convert my B > matrix to g/m3 by selecting one profile of liquid water content, > temperature or pressur randomly. The covariances depend on the > atmospheric state. The effect of the atmospheric state on B must really be second order. I think you easily can ignore it. LWC retrievals are tricky as the measurements hardly provide any altitude information. Ask Ole Martin and the guys in Bern for hints, they have worked on this. > Thus, I have already reviewed one my article and said that I cannot > retrieve the liquid water content profile. Now it is the second > review and the reviewer thinks it would be easier with the liquid > water path. Maybe the rate of convergence with the liquid water path > will be better as ground-based microwave radiometers are only > sensitive to the integrated content and not the profile. I don't agree with the last statement, as I tried to explain in my last email. This email is the last help I can provide in this matter. I am just too busy ... Bye, Patrick _______________________________________________ qpack mailing list [email protected] https://www.sat.ltu.se/mailman/listinfo/qpack
