https://www.whoi.edu/cms/files/Fleitmann07_45483.pdf

Holocene ITCZ and Indian monsoon dynamics recorded in stalagmites from Oman and Yemen (Socotra)

Sediments from Lunkaransar dry lake in northwestern India reveal regional water table and lake level fluctuations over decades to centuries during the Holocene that are attributed to changes in the southwestern Indian monsoon rains. The lake levels were very shallow and fluctuated often in the early Holocene and then rose abruptly around 6300 carbon-14 years before the present (14C yr B.P.). The lake completely desiccated around 4800 14C yr B.P. The end of this 1500-year wet period coincided with a period of intense dune destabilization. The major Harrapan-Indus civilization began and flourished in this region 1000 years after desiccation of the lake during arid climate and was not synchronous with the lacustral phase.

/pdf/high-resolution-holocene-environmental-changes-in-the-thar-3v5d9fu5n0.pdf

High-Resolution Holocene Environmental Changes in the Thar Desert, Northwestern India

We have compiled 36 previously published palaeoclimate records to determine the timing and spatial pattern of century-scale abrupt changes in Asian monsoon precipitation since the last deglaciation. We identify abrupt events from (1) the interpretations of the authors of these records and (2) the more objective moving t-test calculation. Our results indicate that abrupt climatic changes occurred at ~11.5 cal. ka, ~4.5- 5.0 cal. ka and ad 1300. At the start of the Holocene (~11.5 cal. ka), Asian monsoon precipitation increased dramatically. This climatic change is synchronous with an abrupt warming in the North Atlantic. During the middle Holocene, there was a time of preferred and widespread weakening in monsoon strength (~4.5- 5.0 cal. ka). This result contradicts previous notions of either a gradual trend towards drier conditions or a series of abrupt events that occurred in an unorganized fashion across space and time. The middle-Holocene abrupt event could have been synchronous with an abrupt cooling event in the North Atlantic, as well as a warming and intensie cation of internannual variability in the tropical Pacie c. In contrast to previous periods, precipitation changes at ad 1300 have a heterogeneous spatial pattern. We e nd no conclusive evidence for a change in the Asian monsoon at ~8.2 cal. ka, as suggested by several previous studies. More high-resolution data may be needed to observe this short-lived event. Overall, our results attest to the potential for rapid and major shifts in Asian monsoon precipitation that may be triggered by variations in other components of the climatic system.

A synthesis of abrupt changes in the Asian summer monsoon since the last deglaciation

Holocene circum-Mediterranean vegetation changes: Climate forcing and human impact

POLLEN analysis is the term applied to the quantitative analysis of material containing pollen, by microscopic recognition of the species and genera of plants from which the pollen came. The pollen membranes have qualities of shape, size, surface, and structure which permit these identifications, and their preservation is often excellent. An Introduction to Pollen Analysis By Dr. G. Erdtman. (A New Series of Plant Science Books, Vol. 12.) Pp. xvi + 240. (Waltham, Mass.: Chronica Botanica Co.; London: Wm. Dawson and Sons, Ltd., 1943.) 5 dollars.

/pdf/an-introduction-to-pollen-analysis-4vjdb3zmyj.pdf

An Introduction to Pollen Analysis

Summary
A general survey of the pollen-rain from the vegetation of north-west India is described. The survey is based on the study of 114 modern pollen spectra from sixty-four different sites. It is revealed that with certain qualifications the major aspects of the extant vegetation belts of north-west India are reflected in the pollen-rain falling within them. In the territory as a whole, the pollen of herbs dominates that of trees and shrubs except in close proximity to one of the latter. Amongst the woody plant pollen that of shrubs is commonest in the arid belts but tree Pollen asserts itself as rainfall increases. The long-distance transport of pollen from one region to another does not affect the overall picture of the pollen-rain to any significant degree except in the areas bordering the Himalayas where pine pollen is over-represented. Cerealia type pollen usually occurs in areas where there is cereal cultivation but remains unrepresented in the very arid belt which is free of cereal agriculture. The pollen frequencies of Acacia, Prosopis, Zizyphus, Salvadora, Maytenus and the species belonging to Leguminosae, Labiatae and Geraniaceae are Under-represented. On the other hand 5% pine pollen occurs even as far as 600 km from the source.

https://nph.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-8137.1973.tb02025.x

Pollen-rain from the vegetation of north-west india

A phased array Doppler Mini-Sodar has been installed at Anupuram near Kalpakkam nuclear site during the Coastal Atmospheric Boundary Layer Experiments (CABLE) carried out on the east coast of India. Mini-Sodar was used to measure the wind profile and investigate the coastal boundary layer development due to land-sea breeze circulation for the study of coastal dispersion of pollutants. The atmospheric boundary layer, its variability during SW (August 13, 14 : ARMEX I and September 3, 7, 11, 14) and pre-monsoon period (April 27, 28 : ARMEX II) 2003 has been studied. Large wind direction change and  high vertical velocity variance were observed  during the onset of sea breeze. The Thermal Internal Boundary Layer (TIBL) height has been found to increase progressively with season: summer - 170 m, SW monsoon - 210 m and NE monsoon - 325 m  whereas the Nocturnal Boundary Layer (NBL)        height decrease progressively during the corresponding period: summer - 370 m, SW monsoon - 340 m and NE monsoon - 210 m.

https://mausamjournal.imd.gov.in/index.php/MAUSAM/article/download/898/745

Atmospheric boundary layer observations on the East Coast at Kalpakkam using Doppler mini-sodar during different seasons

The results from stratigraphy, radiocarbon dating and pollen analysis of three salt-lake deposits at Sambhar, Lunkaransar and Didwana in western Raj9asthan, and one freshwater lake deposit at Pushkar in the Aravalli Hills, are described in conjunction with pollen analysis of some archaeological soil samples from the Indus Valley site at Kalibangan in northern Rajasthan. The salt-lake deposits studied are stratigraphically divisible into (a) pre-lacustrine, (b) lacustrine and (c) post-lacustrine sections. The pre-lacustrine section is characterized by a thick bed of aeolian sand underlying lacustrine sediments, while the lacustrine and post-lacustrine sections are broadly circumscribed by laminated clay and nonlaminated silt respectively. The pollen record from the four lake profiles studied is divided into local pollen zones. Four regional pollen assemblage zones are delineated for the area west of the Aravalli Range in Rajasthan. The environmental history deduced from the pollen record is divisible into phases I-V, of which phases II-V follow the regional pollen assemblage zones. Phase I is stratigraphically determined, and is representative of severe arid environments under which the sand dunes, now stabilized, are suggested to have been active. The plant microfossils first appear in phase II with the deposition of lacustrine sediments dated to around 10000 b . p . The vegetation comprises an openland steppe which is rich in grasses, Artemisia and sedges and poor in halophytes. Artemisa, Typha angustata, Mimosa rubicaulis and Oldenlandia , which now grow under areas of comparatively higher average annual rainfall (above 50 cm), appear to have flourished in the semi-arid belt, while the first two plant taxa had encroached even as far as the arid belt, both suggesting that a general westward shift of the rainfall belts had taken place. Vegetation destruction through burning by man is suggested to have started together with the first occurrence of Cerealia-type pollen at about 7500 b . c . and continued thereafter throughout phases III and IV. The increase in swamp vegetation and the intensification of vegetation cover inland together with the maxima of all mesophytic elements in phase IV ( ca. 3000 b .c . to ca. 1000 b .c .) indicate an increase in the rainfall, apart from a short relatively drier time about 1800-1500 b . c . at Sambhar which correlates with the decline of the Indus culture in northwest India. Phase IV is immediately followed by aridity for which there is stratigraphic evidence that the salt lakes started drying. At Pushkar, there is evidence that the vegetation showed a marked change in the Aravallis. The onset of this aridity is suggested to have been widespread. The climate did not ameliorate until about phase V (? early centuries a .d . to present) at which time the Rangmahal culture perhaps flourished in Rajasthan, the remains of which imply good water supply. In conclusion it is suggested that the Rajasthan desert is primarily natural, its history punctuated by at least one more vegetated, humid period during the Holocene, the climatic control of which as indicated by the vegetation history is consistent with climatic events elsewhere in the world.

Late quaternary history of vegetation and climate of the Rajasthan desert, India

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Pollen-rain from the vegetation of north-west india

Atmospheric boundary layer observations on the East Coast at Kalpakkam using Doppler mini-sodar during different seasons

Late quaternary history of vegetation and climate of the Rajasthan desert, India