Does some one know if there is any record of precipitation isotope in westerlies controlled region? For example, Xinjiang or Central Asia. There are plenty of records of monsoon precipitation isotope records, such as cave deposits.
The timescale better restricted since LGM or the Holocene. Thanks for your help.
Best
I don't know about the existence of monsoon precipitation records in Asia. However, concerning the link "westerlies" and monsoon systems I would say that the first is a large component of the second. For the West African monsoon, the reinforcement of southeasterlies in the south hemispere (let's say at around 5°S) coincides with the begining of the monsoon. The increase of the southeasterlies creates the Atlantic cold tongue, by cooling the sea surface temperature south of the equator (see the oceanic processes at work in my references); then a coupling between the ocean and the atmosphere is established; passing the Equator, the southeasterlies veers to southeasterlies and reinforce the monsoon flow over the ocean. This inflow force precipitation at the coast and the local oceanic circulation helps the monsoon system to migrate northwards. You can find some details of the coupling and link of the southeasterlies with the African monsoon in Caniaux et al. JGR 2011.
The Westerlies, anti-trades,[1] or Prevailing Westerlies, are prevailing winds from the west toward the east in the middle latitudes between 30 and 60 degrees latitude. They originate from the high-pressure areas in the horse latitudes and tend towards the poles and steer extratropical cyclones in this general manner..........now monsoon is...traditionally defined as a seasonal reversing wind accompanied by corresponding changes in precipitation,[1] but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with the asymmetric heating of land and sea
There has been a recent effort to explore Central Asian caves and retrieve speleothemes to map the regions under predominant westerlies or monsoon influence. I know that Sebastian Breitenbach (ETH Zurich) is working on the analysis of samples from Uzbekistan. You can find some isotope data (∂18O ∂D) in a conference paper (ICS 2013) he uploaded in the link below.
You might find additional ressource on his profile page: https://www.researchgate.net/profile/Seb_Breitenbach
Good luck
Conference Paper Element and Stable Isotope Aqueous Geochemistry from Baysun ...