TY  - JOUR
A1  - Anoop, Ambili
A1  - Prasad, S.
A1  - Plessen, Birgit
A1  - Basavaiah, Nathani
A1  - Gaye, B.
A1  - Naumann, R.
A1  - Menzel, P.
A1  - Weise, S.
A1  - Brauer, Achim
T1  - Palaeoenvironmental implications of evaporative gaylussite crystals from Lonar Lake, central India
JF  - Journal of quaternary science
N2  - We have undertaken petrographic, mineralogical, geochemical and isotopic investigations on carbonate minerals found within a 10-m-long core from Lonar Lake, central India, with the aim of evaluating their potential as palaeoenvironmental proxies. The core encompasses the entire Holocene and is the first well-dated high-resolution record from central India. While calcite and/or aragonite were found throughout the core, the mineral gaylussite was found only in two specific intervals (46303890 and 2040560 cal a BP). Hydrochemical and isotope data from inflowing streams and lake waters indicate that evaporitic processes play a dominant role in the precipitation of carbonates within this lake. Isotopic (18O and 13C) studies on the evaporative gaylussite crystals and residual bulk carbonates (calcite) from the long core show that evaporation is the major control on 18O enrichment in both the minerals. However, in case of 13C additional mechanisms, for example methanogenesis (gaylussite) and phytoplankton productivity (calcium carbonate), play an additional important role in some intervals. We also discuss the relevance of our investigation for palaeoclimate reconstruction and late Holocene monsoon variability.
KW  - evaporites
KW  - gaylussite
KW  - isotopes
KW  - Lonar Lake
KW  - monsoon
Y1  - 2013
U6  - https://doi.org/10.1002/jqs.2625
SN  - 0267-8179
VL  - 28
IS  - 4
SP  - 349
EP  - 359
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Menon, Arathy
A1  - Levermann, Anders
A1  - Schewe, Jacob
T1  - Enhanced future variability during India's rainy season
JF  - Geophysical research letters
N2  - The Indian summer monsoon shapes the livelihood of a large share of the world's population. About 80% of annual precipitation over India occurs during the monsoon season from June through September. Next to its seasonal mean rainfall, the day-to-day variability is crucial for the risk of flooding, national water supply, and agricultural productivity. Here we show that the latest ensemble of climate model simulations, prepared for the AR-5 of the Intergovernmental Panel on Climate Change, consistently projects significant increases in day-to-day rainfall variability under unmitigated climate change. The relative increase by the period 2071-2100 with respect to the control period 1871-1900 ranges from 13% to 50% under the strongest scenario (Representative Concentration Pathways, RCP-8.5), in the 10 models with the most realistic monsoon climatology; and 13% to 85% when all the 20 models are considered. The spread across models reduces when variability increase per degree of global warming is considered, which is independent of the scenario in most models, and is 8% +/- 4%/K on average. This consistent projection across 20 comprehensive climate models provides confidence in the results and suggests the necessity of profound adaptation measures in the case of unmitigated climate change.
KW  - monsoon
KW  - variability
KW  - CMIP-5
Y1  - 2013
U6  - https://doi.org/10.1002/grl.50583
SN  - 0094-8276
VL  - 40
IS  - 12
SP  - 3242
EP  - 3247
PB  - American Geophysical Union
CY  - Washington
ER  -